the global magazine of leica...

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The Global Magazine of Leica Geosystems

63

2 | Reporter

Dear Readers,

New technologies are changing working styles and

methods for almost everyone who captures, pro-

cesses, or passes data on to others, or those who

further process or visualize data themselves. Our

everyday tasks and the whole job profile of our

industry have changed over recent decades. The last

10 years, especially, have seen expansion into new

business areas.

One of the technologies that has helped grow our

industry is laser scanning, which allows users to cap-

ture millions of points – whether from the ground or

from the air – in the shortest possible time. Laser

scanning has hugely expanded the range of possible

applications of traditional surveying, while also cre-

ating entirely new ones. Some extraordinary proj-

ects have already been completed with the new Leica

ScanStation C10, such as the scanning of the Mount

Rushmore National Memorial in the USA, featured

on the front cover of this Reporter. Scott Macleod

of Loy Surveys, who took delivery of one of the

first ScanStation C10s in Great Britain, has written

an exciting article on his first experiences with the

instrument.

Another new system, the Leica Viva Series, which we

introduced at the last Intergeo, is playing the lead-

ing role in Swiss mobile phone operator Swisscom’s

major infrastructure project, while models from the

proven Leica GPS1200+ and TPS1200+ series are in

use on the Russian bridge “project of the century”

over the Bosporus.

Now if we’ve piqued your curiosity, I look forward to

your visit at our booth at Intergeo in Cologne.

Juergen Dold

CEO Leica Geosystems

Editorial

Imprint

Reporter: Customer Magazine of Leica Geosystems

Published by: Leica Geosystems AG, CH-9435 Heerbrugg

Editorial Office: Leica Geosystems AG,

9435 Heerbrugg, Switzerland, Phone +41 71 727 34 08,

[email protected]

Contents responsible: Alessandra Doëll

(Director Communications)

Editor: Agnes Zeiner, Konrad Saal

Publication details: The Reporter is published in English,

German, French, and Spanish, twice a year.

Reprints and translations, including excerpts, are subject to

the editor’s prior permission in writing.

© Leica Geosystems AG, Heerbrugg (Switzerland),

September 2010. Printed in Switzerland

Cover: CyArk

CO

NTEN

TS Scanning on

Washington’s Shoulder

Accreditation Creates Confidence

Speeding Up on Channel Project

Embracing Point Clouds

Russian Marvel

Virtual 3D Urban Designfrom Laser Scan Data Big Ship, Tight Space

Utility Mapping with GNSS

CORS-Qatar: Updating Mapsin Real-Time Reacting to Climate Change

Modeling Istanbul: World’s Largest Scanning Project

Controlling Vertical Towers

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The Global Magazine of Leica Geosystems | 3

by Elizabeth Lee

3D laser scanning has already changed the fields

of surveying, engineering, construction, and

forensics. Now, 3D laser scanning is changing

the fields of education, cultural tourism, and

cultural heritage preservation and manage-

ment. With help and support from Scotland and

Leica Geosystems, the non-profit organization

CyArk carried out the first comprehensive docu-

mentation survey of the Mt. Rushmore National

Memorial.

In May 2010, teams from CyArk and the Scottish Center

for Digital Documentation and Visualisation (CDDV),

with additional support from Leica Geosystems,

deployed an array of Leica Geosystems laser scanners

to digitally capture the famous Mt. Rushmore National

Memorial. The memorial is a spectacular sculpture

carved high into the granite face of Mount Rushmore

in South Dakota (USA). It features four 18 m sculptures

of the heads of former US presidents George Wash-

ington, Thomas Jefferson, Theodore Roosevelt, and

Abraham Lincoln, or as many surveyors know them,

“three surveyors and some other guy (Roosevelt).”

Scanning on Washington’s Shoulder

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4 | Reporter

The memorial park site covers more than 5 km² and is

1,745 m above sea level.

The data capture is the first phase of a five-year proj-

ect between CyArk and the U.S. National Park Ser-

vice (NPS) to provide both engineering-grade data for

tasks such as rock-block monitoring, analysis, and site

resource management, as well as a base data set to

create virtual tourism and educational materials for

public outreach and data dissemination.

The project deployed up to three teams, operating

five scanners at once, in various locations throughout

the park and on the mountain. Complete coverage of

the mountain sculpture was a necessity for the engi-

neering and interpretive needs of the park; therefore

it was critical that all surfaces be scanned at a high

level of accuracy and resolution.

Four Leica Geosystems scanner models were used:

Leica ScanStation 2, Leica HDS6000, Leica HDS6100,

and the new Leica ScanStation C10. Each scanner mod-

el was strategically deployed within the site to utilize

its unique strengths; for example the ScanStation 2

with its long-range capabilities was used along the

base of the mountain. The speed and dense data cap-

ture abilities of the HDS6000 and HDS6100 were used

to capture all the details in the canyon behind the

sculpture and throughout the park grounds. Because

of its blend of range and speed the ScanStation C10

was used as the workhorse atop the mountain for

wide-view scans of the sculpture.

The new compact design of the ScanStation C10 and

its on-board controls were essential for using the

scanner in precarious positions on the mountain. In

one setup location, the NPS ropes team and scan team

lead, Douglas Pritchard of CDDV, rappelled from the

top of the monument down to George Washington’s

shoulder with the scanner. With the scanner secured

on the president’s shoulder and the scan settings

selected, Pritchard and the ropes team then rappelled

off the side of the shoulder to avoid obstructing the

scan. Scans captured from these positions were criti-

cal to the success of the project.

To ensure accuracy and complete coverage of the

mountain, a data command center was set up on

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The project was a tremendous success, resulting in

the first comprehensive survey documentation of Mt.

Rushmore. The capture of this American icon com-

plete, CyArk is now at work creating the engineering

and educational deliverables to supplement the laser

scan data in the CyArk archive. There, a digital 3D

Mt. Rushmore will sit alongside world treasures from

around the globe as the CyArk team takes on future

challenges to bring state-of-the-art survey and docu-

mentation techniques to other heritage sites for the

benefit of future generations.

About the Author:

Elizabeth Lee is Director of Projects and Development

at CyArk. http://archive.cyark.org/


site and all team members were equipped with two-

way radio systems. CyArk’s Justin Barton used Leica’s

Cyclone software to do daily registrations of the data.

This allowed the scan-team members on the mountain

or on the visitor’s trail to radio the command center

for up-to-date information on the scans and instant

feedback on proposed scanner setup locations.

The CyArk 500 and the Scottish 10

The non-profit organization CyArk was created to

apply the advantages of 3D laser scanning or High-

Definition Surveying™ (HDS™) to the field of digi-

tal heritage preservation. Rather than transporting

engineers to a digital plant, CyArk virtually transports

students and web travelers inside Native American

ruins at Mesa Verde National Park (USA) or to the

top of the Leaning Tower of Pisa in Italy. Instead of

capturing a crime scene for analysis, CyArk works to

capture cultural heritage sites around the world to

create a shareable, 3D digital record of humanity’s

tangible history.

CyArk was created shortly after the Taliban’s dramat-

ic destruction of the Bamiyan Buddhas in Afghani-

stan. Often credited as the Father of Laser Scanning,

Ben Kacyra knew the power of laser scanning to cap-

ture the built environment. Envisioning the creation

of a cyber archive for humanity’s cultural wonders of

the world, Kacyra (who also founded Cyra Technolo-

gies – now the laser scanning business unit of Leica

Geosystems), founded CyArk in 2003.

To date, CyArk has utilized HDS technologies to cap-

ture, process, archive, and disseminate digital data

for over 30 heritage sites around the world. This

progress became the catalyst for launching the

“CyArk 500 Challenge”, a challenge to digitally pre-

serve 500 important heritage sites. Upon hearing

about CyArk 500, the Scottish Minister of Culture,

Michael Russell, was impelled to get involved. Already

using HDS technology within Scotland and eager to

contribute to CyArk’s global mission, the visionary

Scottish Minister made the generous commitment of

the “Scottish 10”, the contribution of 10 projects

to the CyArk 500. These projects consist of the five

UNESCO World Heritage Sites within Scotland and

five international projects.

6 | Reporter

by Sabine Reischmann

Leica Geosystems is one of few surveying instru-

ment manufacturers in the world that is allowed

to issue calibration certificates as a nationally

accredited body. This expertise means increased

transparency and better comparability. Accredi-

tation and certification creates confidence in

the mind of the customer. And to take this a

step further: Leica Geosystems customers also

gains from the confidence that their clients

place in them.

René Scherrer and Wolfgang Hardegen, the current

and future managers of the accredited calibration

laboratories for Leica Geosystems in Heerbrugg,

compare calibration certificates with the fuel pump

gauge at filling stations: “The customer must be able

to trust that the gauge shows the actual quantity of

fuel being pumped. The customer can be sure that

what we promise is delivered.” A calibration certifi-

cate can be traced back to national standards and the

measurement uncertainties of the measured values

are fully documented. For the customer, this means

that he can be certain the actual parameters and

specifications of his Leica Geosystems product cor-

respond with those quoted in the product literature.

Several factors are critical to attaining the status

of an accredited body. Hardegen identifies the first

as quality management: “Our quality management

system, which is certified in accordance with ISO

9001, forms the basis for accreditation.” The exper-

tise of our staff is crucial: “All employees who work

in the calibration laboratory at Leica Geosystems

are trained accordingly.” Further prerequisites in-

clude an appropriate technical and organizational

infrastructure. Technical infrastructure includes the

premises; facilities and procedures; and consists of

the measurement baseline as well as laboratories for

distance, angle, frequency, and level measurements.

A further accreditation is being sought to augment

these five laboratories with a test laboratory for

laser classification.

Baseline

The baseline is not a typical laboratory, as it is situ-

ated on the west bank of the Rhine river at Kriessern,

a village near Heerbrugg. “The bank of the Rhine

here is straight for a length of three kilometers with

no obstructions to the line of sight – something sel-

dom encountered in the densely populated Rhine

valley among high Alpine peaks,” explains Hardegen.

Leica Geosystems can check the standard deviation

of distance measurements over lengths of 500 m,

Accreditation Creates Confidence


1,000 m, 2,000 m, or 3,000 m. The accurate determi-

nation of atmospheric parameters, such as tempera-

ture, pressure, and humidity is essential to obtain

precise results.

Calibration Laboratory for Distance

The calibration laboratory for distance, dubbed the

“railway line” by staff because of its length and

design, is used to determine deviations from linear-

ity over distances of 60 m and 120 m. The results

from this test determine the deviation of the highly

accurate interferometer distance compared to the

measured distance.

Calibration Laboratory for Angles

The calibration laboratory for angles is used to deter-

mine the standard deviation of horizontal and verti-

cal angle measurements. Leica Geosystems devel-

oped a very complex, highly accurate theodolite

testing machine (TPM), the only one in the world, to

carry out this task. This machine checks the horizon-

tal circle and zenith angles of the instrument com-

pletely automatically.

Calibration Laboratory for Frequency

In the calibration laboratory for frequency the accu-

racy of electronic distance meters (EDM) is checked

in a climatized cabinet that can be set at any tem-

perature between - 20° C and + 50° C. Analysis of the

frequencies determines the scale error of the EDM.

Calibration Laboratory for Levels

In the calibration laboratory for levels compensator

setting accuracies or horizontal optical line of sight

of levels are determined.

The demand for certificates is continuously rising

for various reasons. Wolfgang Hardegen cites the

increased competitive capability of customers in ten-

dering for public works contracts as a strong driver.

Large private companies also often ask for certifi-

cates or customers themselves like to be accredited

according to ISO 9001. But the main value added

for the customer is still increased transparency, con-

firmation of confidence in the instrument by Leica

Geosystems, and the improved comparability with

respect to other products.

About the author:

Sabine Reischmann is Marketing Communications

Executive at Leica Geosystems in Heerburgg/Switzer-

land.

Accreditation of

Calibration Laboratory

In 1997, the Swiss Accreditation Service (SAS),

which forms part of the State Secretariat for Eco-

nomic Affairs (SECO), confirmed Leica Geosystems in

Heerbrugg as an accredited body with a calibration

laboratory for distances and angles. Through multi-

lateral agreements with international organizations

such as EA (European cooperation for Accreditation)

and ILAC (International Laboratory Accreditation

Cooperation), these certificates are internationally

recognized in well over 100 countries. “Calibration

certificates are legal documents. Their falsification is

considered forgery and perpetrators would be appro-

priately punished,” stresses Wolfgang Hardegen, as

he highlights the credibility of the certificates.

Calibration laboratories have to be accredited by the

Swiss Accreditation Service (SAS) every five years.

Annual audits are carried out in accordance with

ISO/IEC17025 by the supervisory authorities between

accreditations. Official information about Leica

Geosystems’ accredited laboratories (SCS 079) can

be found on the SECO website (see below; search for

079 under Search “Accredited bodies”). The docu-

ment lists the tests the laboratory can carry out, as

well as measurement accuracies and uncertainties.

http://www.seco.admin.ch/sas/

8 | Reporter

Speeding Up on Channel Project by Daniel C. Brown

A 3D excavator guidance system is helping

earthmoving subcontractor Ebert Construction

beat the schedule by 15 percent on a 9-million

USD channel repair project for the U.S. Army

Corps of Engineers in Topeka, Kansas.

Ebert Construction Co., Wamego, Kansas, is using

Leica Geosystems machine control systems on its

excavators to help reshape 2.5 miles (4 km) of the

channel at Soldier Creek, which is contained by two

parallel levees spaced 300 feet (91.5 m) apart. In

2005 a major flood eroded the creek banks. This

project will repair the damage, helping to prevent

further flooding upstream of the reconstructed area.

Ebert has engaged a fleet of earthmoving equip-

ment to remove 350,000 cubic yards (270,000 m³) of

earth from the side slopes and take them to waste

areas behind the levee. Some 170,000 cubic yards

(130,000 m³) are being moved from cuts to fills on

the slopes.

Two hydraulic excavators, each fitted with a Leica

PowerDigger 3D machine control system, are being

used to shape the side slopes. Each slope is designed

with an upper and a lower bank, both on a 3:1 slope

and separated by a gentler 10:1 slope. Jim Ebert,

project manager for the contractor, says the Leica

PowerDigger 3D systems improve the excavators'

efficiency because no grade checking is needed. He

further states that the systems save Ebert 40,000

USD a year by eliminating the grade checker. The

PowerDiggers' screen shows the operators the cuts

and fills on a continuous basis. “Plus”, says Ebert,

“we can work underwater without having a grade

checker climb into the water.”

“The Leica Geosystems GPS system takes the guess-

work out of grading for the operators,” says Trent

Ebert, project superintendent. “And there's no more

calling us to say the stakes got run over by a dozer.

There's no downtime. Nobody has to watch the oper-

ators; they can dig, back up, find the next place to

cut and keep on going.” Completion is scheduled for

February 2011, but the contractors hope to achieve

substantial completion before winter.

About the author:

Daniel C. Brown is the owner of TechniComm, a com-

munications business based in Des Plaines, Illinois/

USA.


by Scott Macleod

Loy Surveys had been aware for a number of

years that laser scanning was going to be the

next big thing in surveying and would eventually

become a mainstream technology. They knew

they would have to master it in order to stay at

the leading edge of surveying. The only question

was, when? Senior Surveyor Scott Macleod on

how they met the challenge.

With the technology changing at a rapid pace and

becoming increasingly more affordable, it was a case

of finding the right balance. Fortunately we had the

opportunity to purchase the first commercially avail-

able Leica ScanStation C10. This is a bit of kit that

appealed to us and our style of workflow in a big

way. Not only was it a significant step ahead of previ-

ous scanners, it provided us with an excellent entry

point into scanning. Being both faster and lighter

it was ahead of the game and looked as though it

would be the pacesetter for the next few years. The

fact that everything came in a single manageable

package and did not need cables, external batteries,

and laptops to operate it, meant it fitted perfectly

into our flexible working system. Once in possession

of the Leica ScanStation C10 we were able to put it

straight to work.

Embracing

Point Clouds

>>

10 | Reporter

Monitoring Cooling Towers

With a job in the pipeline we were able to get an

early delivery of the ScanStation C10. The job was

to carry out a survey of three cooling towers at

the Grangemouth Oil refinery on Scotland’s Firth of

Forth. The ScanStation C10 was delivered to us on

the first morning of the job by Steven Ramsey from

Leica Geosystems. Steven was there for more than

just delivery. He had been involved in the testing and

development phase of the ScanStation C10 and, as

we were going to be the first company to use it on

commercial work, he joined us so that he could dem-

onstrate its capabilities and observe the scanner in a

commercial environment.

The purpose of the job was to survey the cooling

towers with a view to identifying any movement

and changes of shape or deformations in the tower

structures. Previous surveys had involved observing

points at set heights along a number of vertical lines

around the tower. Although these surveys had not

been carried out by Loy Surveys, we believed that

this method of setting out and surveying fixed points

around the tower could take two or possibly more

days per tower. By using the ScanStation we were

able to survey the three towers over the course of

two days, with a survey time for each individual tow-

er of approximately 2 ½ hours.

Not only was this a massive saving in site time, we

were also able to record infinitely more data on the

cooling towers. Each tower was scanned by plac-

ing the ScanStation C10 over known control points.

A total of five overlapping positions were used on

each tower and they were scanned at a 30 mm grid.

Importing and registering the individual scans proved

straightforward with the Leica Cyclone 7 software

and in less than an hour’s office time we had a 3D

model of the tower.

Dounreay Castle

One of our most recent jobs has been to carry out

a 3D scan of Dounreay Castle on Scotland’s north

coast. The castle, a scheduled monument (protected

national monument), is unique in this area of Scot-

land, as it has an L-shaped footprint that is more

commonly found in the Scottish Lowlands. This

makes it an important part of the history and heri-

tage of the area.

“... future comparisons

between 3D scanned

models will not be so

cumbersome ...”

As the castle is in a poor state of repair, Historic

Scotland are keen to see something done in order

to maintain and preserve the castle. It is current-

ly owned by the Dounreay nuclear facility and is

trapped by the coast on one side and the nuclear

facility on all others. The nuclear plant is currently

being decommissioned and the security and monitor-

ing controls in place during this process mean that

it is not viable or affordable to carry out a physical

restoration of the castle at present.

With this in mind we were approached by Dounreay

Site Restoration Ltd and asked to carry out a 3D scan

of the castle as a means of preservation by record.

Only an exterior survey of the castle was possible.

Its dilapidated condition meant that for health and

our productivity. For our clients, they are able to get

full 3D surveys in a fraction of the time and at an

affordable price. At present however, only a small

number of our clients are in a position to accept and

deal with full point cloud data, but this is something

we are keen to rectify.

With the purchase of the Leica ScanStation C10, Loy

Surveys has taken a major step into the world of 3D

scanning. In doing so we are expanding our capabili-

ties as a survey company and keeping ourselves at

the leading edge in a competitive industry. Having

put the ScanStation C10 to use, it is easy for us

to see the huge advantages to be gained through

highly detailed rapid 3D surveys, produced in record

time. Although new to scanning and still with much

to learn, we have no doubt that we have made the

right move at the right time.

About the author:

Scott Macleod originally worked as an archaeologist,

but soon developed an interest in land and building

surveying and joined Loy Surveys four years ago.


safety reasons we were not allowed within 10 m of

the structure. The ability to scan the castle was ideal

as it meant we could record it quickly and efficiently

at relatively low cost (compared to physical restora-

tion), and at the same time remain at a safe distance

from the structure.

The survey itself was carried out over two days with

a total of eleven overlapping scan positions. At a

different site, without the security protocols, we

could potentially have completed the survey in a day.

The castle was surveyed with an overlapping grid of

8 – 10 mm or less so that we had enough information

to see and record the individual stones within the

coursework. The end product for the client was the

full point cloud data, which they could present to His-

toric Scotland as a record of the castle in its current

state for future use and reference. We also produced

2D elevation drawings.

Convincing Clients

Looking at the long term, we see scanning as becom-

ing the norm in the survey world, and are aiming to

reach an ideal position where we will carry out the

scanning, register the data, and then pass the raw

point cloud straight to the client so that they can use

the data as they see best. This has huge benefits for

both us and our clients. For us it means less office

time and accordingly more survey time, which boosts

“… we have made the

right move at the right

time …”

12 | Reporter

Russian Marvel

by Pavel Antonov

Once finished, the “Bridge to Russky Island”

will connect the city of Vladivostok with Russky

Island and it is no exaggeration to say it is “the

project of the century”. The bridge will be the

largest in Russia and one of the longest world-

wide, with a total span length of 3,100 m. The

1.2 billion USD project, also proudly called “The

Russian Bridge”, is scheduled to be finished

by the opening of the Asia-Pacific Economical

Cooperation summit to be held in 2012 in Vladi-

vostok. Leica Geosystems equipment was cho-

sen to execute the surveying work.

In September 2008 the main contractor, USK MOST,

started construction work for the “Bridge to Russky

Island” across the so called “Eastern Bosporus”,

connecting Russky Island to the city of Vladivostok.

Before it even started, it had already gained the sta-

tus of one of the most demanding building projects

in history. Not only because of the sheer dimensions

of the bridge – the unique central span of 1,104 m

will be the longest in the world, the 320 m tall bridge

pylons will be the highest – but also because the

works are to be carried out on a tight schedule while

extreme winds, sea currents, and seismic activity are

a great challenge for the professionals involved.

Due to very strict project requirements, all surveying

tasks are being carried out with the highest possible

accuracy: from construction design to post-construc-

tion control. This is why Leica Geosystems equipment

was chosen to help complete this demanding job.

Surveying Tasks During Construction

The first task for the contractor was to supply a

precise and reliable control network. A geodetic net-

work (complying with the requirements of the State

Geodetic class II network) was created on Nazimova

Peninsula and Russky Island. The contractor had to

re-determine position and height coordinates of the

network points every six months, but as this was

nearly impossible to do with optical equipment, GNSS

sensors were chosen for the task. A reference sta-

tion mounted by Leica Geosystems’ Russian dealer

and partner Navgeocom was already available in

nearby Vladivostok, to deliver correction data for

precise RTK measurements. Two more reference

stations were mounted on Nazimova Peninsula and

Russky Island, both equipped with Leica GPS 1200+

GNSS sensors.

Before starting measurements in real time surveyors

had to determine transformation parameters from

WGS84 datum to the local coordinate system, so that

RTK jobs could be used in the local coordinate sys-


short time, it has completely fulfilled and surpassed

our expectations! Firstly, Leica Geosystems sensors

have a comprehensive, friendly user interface – this

means less loss of work time. Secondly, the equip-

ment performed magnificently in our severe environ-

ment with snow, wind, and low temperatures, all of

which never interrupted our sessions.”

USK MOST professionals have also remarked on some

of the exceptional functions of Leica Geosystems

equipment, such as the excellent performance of

the Leica TPS1200+ laser pointer by night. With this,

measurements could be performed even 450 m from

the total station. After the pylon height exceeds

100 m, triangulation will not be possible any more,

so professionals working with a combined TPS/GNSS

system. “Leica Geosystems equipment is modular

and scalable,” says Anton Shirokov, “you can work

with a total station or combine it with a GNSS sys-

tem, to set up a Leica SmartStation or a Leica Smart-

Pole. This way, you obtain baseline measurements to

perform tasks even when the visibility is poor.”

About the author:

Pavel Antonov is head of the technical department

of Navgeocom, Leica Geosystems’ authorized dealer

in Russia.

tem. Anton Shirokov, senior surveyor at USK MOST:

“Every construction stage was thoroughly controlled

by different geodetic methods; this is why we were

able to fulfill all requirements of geodetic tasks. The

difference between parameters obtained by TPS and

GNSS measurements were no more than 3 – 4 mm,

which was within the required tolerances. GNSS sur-

veying is really important when there is no way to

perform TPS measurements.”

Due to the strict requirements, surveyors had to

draw from their wealth of professional know-how

and experience in every construction phase. For

example: to obtain the most precise positioning for

bridge pylon parts, engineers used “conductors” (or

“towers”). Connected within different levels of con-

crete, these elements helped strengthen the whole

construction. There came a time when it became too

difficult to use total stations for this task, so Leica

Geosystems GNSS receivers were used to position

these “towers” in their proper place in real-time.

GNSS-technology helped reduce work time from

approximately 1.5 hours per “tower” to 15 min. The

time benefit is obvious.

Leica Geosystems Was the Best Choice

“We only started to work with Leica Geosytems equip-

ment in February 2010,” says Anton Shirokov. “In this

USK MOST

USK MOST was founded in 1991. A highly profes-

sional team, experienced in another “construction

project of the century” – the long term construction

of Baikal Amur Railway Project (BAM, 1975 - 1990) –

Bridge to Russky Island

Total bridge length: 1,885.5 m

Bridge width: 29.5 m

Number of driving lanes: 4 (two in each direction)

Under clearance: 70 m

Number of bridge towers: 2

Bridge tower height: 320.9 m

Number of cable stays: 168

Longest/shortest cable stay: 578.08 m/181.32 m

The bridge piles will be driven 77 m below ground.

On the island side 120 auger piles will be piled under

each of the two 320 m high bridge towers. The bridge

towers will be concreted using custom self-climbing

forms in pours of 4.5 m. Due to the A-shape of the

towers the use of standard forms is not feasible. An

individual set of forms were constructed for each

bridge tower. (Source: www.wikipedia.org)

runs the company. Nowadays “USK MOST” is a hold-

ing consisting of 15 different companies. Its activi-

ties cover repair and construction works for bridges,

pipelines, tunnels, etc.

14 | Reporter

Virtual 3D Urban Designfrom Laser Scan Data

by Konrad Saal

The Inselhalle in Lindau, Germany, a conference

center on an island in Lake Constance, was to

be refurbished and extended to meet modern

requirements. Since only incomplete records of

the original building existed, project organiz-

ers decided to capture the existing features of

this old conference hall and its surroundings

using laser scanning. The acquired data is now

available to architectural consultants for their

designs and for virtual “tours”.

Consulting engineers Zimmermann & Meixner Z&M

3D Welt GmbH, from nearby Amtzell, won the con-

tract for the building inventory documentation and

3D visualization. Their task was to capture the details

of the whole hall (interior and exterior) and the adja-

cent features including the bank of the lake in the

vicinity of the conference hall.

Survey of Existing Features Using

3D Laser Scanning

Surveying technician Viola Leibold and graduate

engineer Benjamin Sattes arrived on the island with

a Leica ScanStation 2 to produce as-built record-

ings of the original buildings and surrounding fea-

tures. This versatile 3D laser scanner captures up to

50,000 points per second and has a range of up

to 300 m. “Laser scanning provides surveyors with

a way to overcome the hurdle of capturing the fea-

tures of existing objects at an adequate level of

detail precisely and cost-effectively,” explains Ben-

jamin Sattes.

“The 3D laser scanner is linked to a laptop and con-

trolled using the Leica Cyclone software package,

which consists of several different modules. This

arrangement allows the user to define the required

scan window and point density and store the cap-

tured point data. Targets are set up and scanned at

the same time as the object to permit subsequent

geo-referencing, the linking of all captured point

clouds into a single, consistent system. We captured

an area of about 73,000 m² from 38 stations in five

days. The interior, for which we needed about 21

stations over three days, involved a total area of

5,000 m²,” says Viola Leibold. The Lindau fire brigade

even made a turntable ladder available to capture the

roofscape.


To edit the point clouds Leica Geosystems offers

modules that can interface with a number of engi-

neering CAD programs, allowing users to work in

their familiar software environment. The expanded

and partially automated functions in Leica CloudWorx

for AutoCAD allowed Benjamin Sattes to generate a

3D model of the whole object from the point clouds.

“Any section or view can be generated from the

model once complete.” Two cross-sections; layout

plans of the basement, ground, and first floors; as

well as four views were generated for the Inselhalle.

The 25 architectural consultancies selected for the

design competition used the model as the basis for

their designs. With a maximum deviation of one cen-

timeter from the actual dimensions of the building,

the data is considered equivalent to surveys of the

highest quality.

3D Visualization and Virtual Tours

“The particular aim of the exercise was to capture

the features of the Inselhalle at such a level of detail

and precision that the architects would have access

to a robust and comprehensive survey of the existing

building and would not have to produce one them-

selves,” explains Benjamin Sattes. “At the same time,

we were able to use Leica Geosystems’ free Internet-

based visualization software TruView to allow people

to take a virtual tour of the Inselhalle.”

Leica TruView can be used to analyze and take mea-

surements within large point clouds in a CAD or other

3D technology environment, even for users without

3D laser scanning experience. The point clouds are

presented as photorealistic images. Architects can

move around in a virtual world inside the point cloud,

measure distances, highlight details, make annota-

tions, and save the results. The project participants

can also use the processed data to communicate

effectively over the Internet. Using 2D layouts and a

3D model of the existing building, and with TruView

as a substitute for a site visit with the additional

feature of being able to take measurements, each

architect has the optimum basis for expressing his

ideas and designs.

Linking Designs to the Real World

Thanks to the visualization concept developed in-

house by Z&M 3D Welt, the architects, civil engi-

neers, and landscape planners can see how their

proposals and plans would look in the context of the >>

Leica TruView: Moving around in a virtual world in-

side the point cloud to take distance measurements.

16 | Reporter

Z&M 3D Welt is able to visualize the real environment

from the raw laser scanning results. The captured

point clouds visualize the existing objects and do not

have to undergo further processing into 3D models

with the customary loss of detail and accuracy.

The Sustainability of Using 3D Models

Users are often faced with the question of how best

to make data available for future use with minimum

cost and effort. The data obtained from laser scan-

ning can be accessed immediately to provide mea-

surements from the 3D model and pass them on to

the judging committee. The competitors particularly

appreciate the ease of operation – it is so easy that

no experience is needed to move about freely within

the model.

The future designs and animations for the “Inselhalle

Lindau” project can be found at: www.zm-3dwelt.de/

inselhalle.

About the Author:

Konrad Saal is a surveying engineer and Marketing

Communications Manager with Leica Geosystems in

Heerbrugg, Switzerland.

real situation. The design results can be delivered to

Z&M 3D Welt as 3D models or 2D views. The company

will then develop 3D models from the 2D drawings

or directly import the 3D models created in the cus-

tomer's own choice of software module. The data

is visualized in three-dimensional space with a new

road layout, open space design, landscape architec-

ture, and the existing real buildings and features.

The process is particularly interesting because of its

cost-effectiveness compared to previous methods:


The crane’s designers knew this, and planned to

cut and fold the cranes shortly before passage was

attempted. But this still left plenty of uncertainty. To

be sure he was making the right call, Murtha would

have to precisely equate tidal elevation values and

NAVD 88 (North American Vertical Datum of 1988),

determine the absolute Bay Bridge clearance, and

verify the total height of ship and cranes. And just

to complicate matters, he would have to do it all in

real-time; the San Francisco Bar Pilots who oversee

large vessel operations in the Bay wanted verifica-

tion of sufficient clearance as the cranes approached

the Bay Bridge. The Bay Bridge, incidentally, is known

to have several feet less clearance than the Golden

Gate Bridge, so Murtha’s work would automatically

confirm that the cranes could pass under the Golden

Gate.

Murtha had an idea that made use of his extensive

experience with leading edge survey techniques:

“Since RTK GPS methods are now being used to mea-

sure elevation profiles of airport runways, it didn’t

seem like a big stretch to adapt RTK methods to

verify load clearance. I told people in my organiza-

Big Ship, Tight Space

by Brad Longstreet and Dave Murtha

With a clearance of about 226 feet (69 m)

between Mean Lower Low Water (MLLW) and the

span underside of the San Francisco Bay Bridge,

there’s usually plenty of room for the world’s

biggest ships to pass through on their way to

the Port of Oakland. But when one of those

ships is loaded with three of the world’s tall-

est container cranes, maybe there’s not enough

room … or maybe there is. The job of deciding

fell to Dave Murtha, the Port’s chief surveyor.

The cranes in question are “Super-PostPanamax”

and they’re monsters – PostPanamax ships are too

big for the Panama Canal, and as more are built,

ports around the world are installing cranes that can

accommodate them. In this case, the cranes being

delivered are wide enough to reach across vessels

carrying up to 22 Sea-Land style cargo containers

side by side. Of more concern to Murtha was their

height: 253 feet (77 m). When loaded on a ship big

enough to carry them, this would easily exceed the

Bay Bridge’s clearance. >>

18 | Reporter

tion that I could measure the height of the cranes

as they approached the bridge. Eventually my claim

got passed on to the San Francisco Bar Pilots, and

they were very interested in having me provide that

information.” Airport runway profiles can be post-

processed and re-measured if necessary … but giv-

en the inertia of giant cargo vessels, there would

be no second chances to re-measure as the cranes

approached the bridge.

Laying the Groundwork

Providing real-time information for this project re-

quired painstaking preparation for several reasons.

For example, Murtha knew he needed a backup plan.

“Redundancy was a very important part of the sur-

vey plan,” he says, “Two different RTK rovers would

be used at the top of the load of cranes, one using

cellular modem communication equipment, and the

other using a spread-spectrum radio modem.”

The cellular modem could access a Leica GRX1200

Pro permanently installed at the Port’s headquar-

ters. This receiver is part of RTKMAX, a subscription

real-time network operated by Haselbach Surveying

Instruments (Leica Geosystems’ authorized dealer

for Northern California). But for reliable radio link

RTK, he would need a base station with line-of-sight

from both the Golden Gate and Bay Bridges. “The

levee on the west side of Treasure Island was the

perfect location,” says Murtha.

Work was already underway to verify the Port’s ref-

erence station and relate it to tide station values.

Murtha says: “I included the Port’s reference station

in a GPS control survey which I am submitting to

the National Geodetic Survey (NGS). The control sur-

vey was mostly conducted in June 2009 using Leica

ATX1230GG antennas. Additional vectors focusing on

height differences were measured in August 2009.

This control survey consists of more than 100 vec-

tors and also includes several miles of leveling con-

ducted in June 2009 with a Leica DNA03 digital level

and a calibrated pair of Wild GPCL3 Invar rods. Four

different tidal bench marks were part of this control

survey.”

To supplement the work for the crane height sur-

vey, Murtha planned a static control survey with two

objectives: establish the needed base station loca-

tion and elevation on Treasure Island, and relate local

tide datums to NAVD 88. He included six stations in

the final network. With control firmly established;

tide related to available benchmarks and NAVD 88;

and the Treasure Island station set, Murtha could

move on to additional tasks in this challenging proj-

ect: verifying Bay Bridge clearance and crane height

above the deck of the transport vessel.

Tricky Measurements on the High Seas

In 2000, when a shipment of Post-Panamax con-

tainer cranes was delivered to the Port of Oakland

at the Navy’s former Fleet Industrial Supply Center

(FISCO) in Oakland, Port personnel measured the Bay

Bridge’s mid-span clearance by trigonometric leveling

methods. This time, Murtha used RTK to establish

a spot elevation on the upper deck of the bridge,


then used a Leica TCRP 1201 total station to transfer

elevation from that point to a magnetically mounted

prism target that was visible from the upper deck and

from the base of the nearest suspension tower pier.

Then, in what must have been a fun day in the field,

Murtha took a boat to the pier and set up his total

station. Two CalTrans (California Department of

Transportation) employees, certified to climb on the

bridge, used safety harnesses and belaying equip-

ment to set another prism directly on the bridge’s

bottom chord. Murtha was able to confirm a clear-

ance of 226 feet (69m) above MLLW.

The three cranes, standing their full 253 feet (77m)

tall, arrived at Drake’s Bay, north of San Francisco, on

March 12, 2010, loaded on the Zhen Hua 15, a tanker

with a specially modified low deck. While anchored at

Drake’s Bay, the crew of the Zhen Hua 15 spent three

days folding over the crane apexes. Two days later,

Murtha traveled by boat to the vessel to verify the

final crane height, and to set GPS antenna mounts

at the top of the middle crane. It turned out to be

another exciting day in the field: “The crew of the

Zhen Hua hoisted our equipment up to the boom

level of the crane, which is about 180 feet (55 m)

above the deck of the vessel. Since the apex had

been folded over more than 70 degrees, the stairs

to reach the boom of the cranes were much more

difficult to climb – think of a jungle gym 200 feet in

the air slowly rocking back and forth with the waves.

Once we got to the top we set ourselves to the task

of setting up the GPS antenna mounts. I had modi-

fied two old tripods by removing the metal points

and replacing them with three inch (7.6 cm) diam-

eter disk magnets attached to the tripod legs by

metal hinges. Since tripods are excellent for setting

up over non-level surfaces, I figured these modified

tripods would be the best way to setup the antenna

mounts.”

With antenna mounts in place, Murtha and his crew

returned to the deck to take total station measure-

ments. Since the rolling of the deck ruled out the use

of the vertical compensator – “I could see the bull’s

eye bubble moving back and forth” – Murtha turned

it off and took a series of measurements intended to

define the deck plane and crane height above deck.

Back in the office, he “performed a classic seven-

parameter, three-dimensional coordinate transfor-

mation,” which confirmed what the crew’s engineers

had told him – the cranes had been lowered even

more than planned, and should clear the bridge with

about 10 feet (3 m) to spare.

The Big Day

The transit was set for March 16th. The Port of Oak-

land employees once again climbed to the boom

level, donned safety harnesses, and climbed to the

top of the center crane. Even with all the checking

and rechecking, it was still a tense moment; “We

got there just a few moments before the Zhen Hua

reached the Golden Gate Bridge,” says Murtha, “and

we were happy to see it pass under with what looked

like 15 feet (4.5 m) of clearance.”

Murtha put his equipment into stakeout mode and

started gathering data: “We hadn’t yet reached Alca-

traz, so we were still more than three miles away

from the Bay Bridge, and I was able to tell the pilot

that we had 9 feet (2.7 m) of clearance. I called him

again when we were between Alcatraz and Treasure

Island, and he called me once more when we were

much closer to the Bay Bridge to confirm the clear-

ance values. Shortly after that I realized I could see

the bottom of the bridge, so I called him on the radio

one more time and said, ‘I can see the bottom of the

bridge. We’re definitely going to clear it!’”

About the authors:

Brad Longstreet is a freelance writer who specializes

in construction and surveying. Dave Murtha is the

Chief Surveyor for the Port of Oakland.

20 | Reporter

Utility Mapping with GNSS by Thorsten Schnichels

Reliable digital data acquisition, robustness,

and ease of use – these were the requirements

stipulated by Swisscom AG when it set out to

acquire new GNSS instruments to determine

the positions of telecommunication infrastruc-

ture in the company's country-wide fixed-line

network. After a detailed evaluation the Swiss

telecommunications company decided in favor

of Leica Viva GNSS.

“Determining and recording the position of items in

our telecom network has been a long-standing daily

chore for us – in particular since cables were first

buried underground,” explains Andreas Häsler, Tech-

nical Project Manager at Swisscom. The conventional

methods being used were time-consuming and error

prone. Swisscom was therefore seeking a more effi-

cient and reliable method of data acquisition that

would reduce these recurring daily costs to a minimum.

Measuring System Requirements

The first requirement was for the measuring sys-

tem to provide reliable digital data acquisition to

allow data transfer to be extensively automated.

Furthermore, the system had to be robust, easy to

transport, and able to be used by staff who had no

detailed knowledge of surveying. The new satellite-

supported surveying system Leica Viva GNSS fulfilled

all these requirements – in addition to the GNSS

and communications technology, the client was also

impressed by the systems’ newly designed, easy to

use software, Leica SmartWorx Viva.

Example of an imported DXF infrastructure map on

the Viva Controller. Measured points and items are

shown immediately.


Comprehensive Training and

Support Concept

At the same time, Swisscom and Leica Geosystems

worked together to devise a comprehensive training

and support concept: ten people identified as Super-

Users, would, after intensive training, pass their

knowledge on to the 150+ Swisscom field engineers

who have access to the large pool of Leica GNSS

Viva instruments. The instruments are managed and

the firmware kept up to date through the myWorld@

Leica Geosystems Internet portal. The same system

offers Super-Users a continuous overview of all sup-

port and service cases.

Besides capturing the positions of existing cables,

the Leica Viva GNSS Rovers will also be used to set

out new telecom cables.

About the author:

Thorsten Schnichels is sales and support engineer at

Leica Geosystems AG, Glattbrugg/Switzerland.

GNSS (Global Navigation Satellite System) receives

GPS satellite data as well as signals from other sys-

tems (e.g. the Russian GLONASS satellites). The high-

er signal density provides more reliable reception,

which is necessary since Swisscom has to carry out

most of its surveys in urban areas. Corrections are

transmitted via mobile phone to the swipos refer-

ence service to achieve an accuracy of 1 – 2 cm.

Instruments and Software

Leica Viva GNSS (GS15, CS10)

used by approx. 150 engineers

Leica SmartWorx Viva software

Simple to operate

Rapid, accurate, and safe capture of objects

Reliable and robust system

Objective

Higher productivity with

better quality at lower cost

Benefits

22 | Reporter

CORS-Qatar: Updating Maps in Real-Time

by Konrad Saal

In the past few years the State of Qatar, a pen-

insula on the Arabian Gulf, has experienced

extensive infrastructure development. More

than twenty years ago the results of a user

needs assessment carried out by the govern-

ment clearly indicated an enormous need for

a fully integrated nationwide GIS. The govern-

ment then established the Centre for GIS (CGIS)

as a department of the Ministry of Municipal-

ity & Urban Planning. It is based in the capital

Doha and became the official mapping agency

of the State of Qatar. Since the end of October

2009, many public and private survey and map-

ping communities have been benefiting from a

nationwide Continuously Operating Reference

Station (CORS) network.

The CORS network was set up with receivers, anten-

nas, high-precision tilt sensors, and GNSS Spider

software from Leica Geosystems. Delivering highly

accurate data and comprehensive customer servic-

es, the CORS network now plays a major role in all

geodetic and topographic surveys to update Qatar’s

maps, as well as in integrating collected GIS data into

the common nationwide GIS database.

CGIS setup the CORS network to help achieve coun-

try-wide, homogenous horizontal and vertical accu-

racy and to ensure the availability of RTK corrections

for all survey and mapping communities in Qatar.

Many agencies can now log on to the CORS network

to carry out their tasks without needing to setup

single base stations. The new CORS-Qatar network

consists of nine reference stations and helps many

organizations using RTK and GIS rovers receive dif-

ferential corrections for their day-to-day activities.

All reference stations are homogenously distributed

throughout the country and were established at Al

Shamal, Al Thakhira, Al Jumailiya, Dukhan, Al Khara-

nah, Abu Samra, Mesaieed and Sawda Natheel, and

finally, at the Qatar University in Doha. Each of the

nine reference stations is equipped with future proof

Leica GRX1200+ GNSS receivers and highly accurate

Leica AR25 choke ring antennas. Due to the high

temperatures in Qatar, the receivers are installed in

air-conditioned indoor and outdoor cabinets. The

control center of the CORS-Qatar network is located

Many public and private survey and mapping

communities now have access to CORS-Qatar.


Points were automatically recorded at regular inter-

vals of 5 m. No office processing of the data was

required and the data could be quickly integrated

into the common CGIS database via GISnet high-

speed network. Qatar is the first country to imple-

ment a comprehensive nationwide GIS and is inter-

nationally recognized as having one of the finest GIS

implementations in the world.

The CORS network is now constantly in use for GIS

and GNSS surveys to keep Qatar’s maps up-to-date.

The network is also used for hydrographic surveys,

offshore and ocean navigation.

In the years to come, as Qatar’s infrastructure devel-

ops further, many of the organizations working with

GNSS will benefit from the homogenous CORS net-

work that provides consistent, high accuracy 24/7. All

installed Leica Geosystems receivers and antennas

are ready for future signals.

More information about the Centre for GIS in the

State of Qatar at: www.gisqatar.org.qa

at the Urban Planning sector building in Doha. CGIS

decided in favor of Leica Geosystems equipment

because of its high quality, outstanding customer

service, ease of use, and product durability. In the

meantime, the system has already passed durability

tests in the Middle Eastern summer temperatures.

Reliable GNSS Data and

Comprehensive Service

The physical stability of the antennas fixed on rig-

id masts is monitored to ensure the CORS network

delivers reliable and precise data. They are moni-

tored by Leica Nivel220 dual-axis high-precision tilt

sensors that deliver an accuracy of 3 mm @ 1,000 m.

The data is continuously streamed to check stability.

Tilt measurements at the Al Thakhira site for test-

ing purposes had proven that the position of the

Leica AR25 is very stable at 0.45 mm. Additionally,

the stability of the climatization inside the cabinets is

monitored by meteo sensors measuring temperature

and humidity.

The CORS-Qatar network is managed by CGIS. With

Leica GNSS Spider, CGIS provides correction data for

precise measurements for RTK surveys through TCP/IP,

network processing, raw data streaming status, and

satellite tracking for its customers 24/7. Leica Spider

Web is used for the convenient distribution of GNSS

data sets for public or internal access via standard

web browsers. The software allows keeping track

of data, downloads, users, and costs while provid-

ing additional services such as automatic coordinate

computation and a constant overview of file avail-

ability and data quality. Registered clients can simply

upload their GNSS raw data. SpiderWeb then uses

one or more nearest reference stations to calculate

the coordinates of their data sets. Leica GNSS Spi-

der with SpiderNet software then processes the raw

data to issue correction information to the users in

the field. The network and the services of CGIS bring

numerous benefits to users of RTK for land surveys.

The system operates without downtime and since

its establishment has routinely been used by land

surveyors and GIS professionals to position them-

selves with high accuracy anywhere within Qatar.

Leica Geosystems Spider Business Center makes it

easy to manage and track customers’ access to the

RTK network services.

Quick and Accurate Update of Maps

After the installation of the CORS network, agen-

cies began mapping Qatar’s main roads in real-time.

24 | Reporter

Reacting to Climate Changeby Konrad Saal

‘Sweden facing climate change – threats and

opportunities’ is the title of final report

SOU2007:60 presented by the ‘Swedish Com-

mission on Climate and Vulnerability’ in 2007.

Appointed by the Swedish government in 2005,

the commission’s task is to assess the impact

of global climate change on the country. Over

the last decades Sweden has suffered from sig-

nificantly rising numbers of floods, landslides,

and erosion. The persistent and increasing risk

will affect buildings, roads, and many other

infrastructure facilities. The Swedish govern-

ment has granted a considerable amount of mon-

ey to protect Sweden’s society, infrastructure,

industry, and agriculture. One of the preventive

measures is a new digital elevation model deliv-

ering highly accurate elevation data of Sweden.

As the Swedish mapping, cadastral, and land reg-

istration authority, Lantmäteriet is responsible for

the national co-ordination of the production, co-

operation, and development of geo-data. In 2009,

Lantmäteriet received a special grant from the gov-

ernment to start the new terrain elevation database

using airborne laser scanning technology. “The exist-

ing national Digital Elevation Model (DEM) database

covering Sweden is unsuitable for most of today’s

tasks. It was initially created only for in-house pro-

duction of orthophotos. Over time, it has become

obvious that a better DEM database is of great

importance for many required activities in the com-

ing years,” states Gunnar Lysell, Business Developer

at Lantmäteriet. Furthermore, the existing model

provides a height accuracy of only ± 2 m and has a

50 m grid spacing.

Highly Accurate LiDAR Data Acquisition

In summer 2009, Blom Sweden AB, a subsidiary

of Norway based Blom ASA, started the five-year

project. They were chosen to provide LiDAR data

to Lantmäteriet, but before the project could start

the Swedish mapping authority needed to verify the

LiDAR data from test flights. Among the equipment

chosen for data capture was a Leica ALS60 airborne

laser scanner. It delivered outstanding results that

fully met Lantmäteriet's expectations.


BLOM Group is a leading international company spe-

cializing in the collection and processing of high-

quality geographic information using airborne sen-

sors and the development of software applications

and services. Andreas Holter, Head of Resources at

BLOM, says: “LiDAR has become an efficient technol-

ogy to create digital terrain models of large areas.

The Leica ALS60 meets Lantmäteriet’s specifications,

delivering a height accuracy on hard and well defined

surfaces of 20 cm or better.” BLOM uses Leica Aero-

Plan60 to set up the ALS60, and the Leica FPES soft-

ware for cost efficient and detailed flight planning

and evaluation. The software computed a total flight

length of 550,000 km in approximately 12,500 lines

for the entire project.

According to the flight plans created in FPES, the

sensor is automatically activated for data acquisi-

tion by the Leica FCMS Flight & Sensor Control Man-

agement System. Up to 70,000 “shots” are captured

per second. The collected data is geo-referenced via

GNSS base stations which provide ground control

points. This data is post-processed through differ-

ent software, such as Leica IPAS Pro, NovAtel’s Graf-

Nav/GrafNet, Leica ALS Post Processor, Terrasolid's

TerraScan/TerraMatch, and BLOM’s own TEPP soft-

ware, and finally converted into ground coordinates

including latitude, longitude, elevation, and intensity

values. Andreas Holter confirms, “We are very sat-

isfied with the support from Leica Geosystems in

the integration of Leica ALS Post Processor with our

own software TEPP. This has sped up the processing

workflow. The accuracy of the final processed data

is very good, mainly because of the high accuracy

Inertial Measurement Unit (IMU). This, combined with

good flight and processing procedures, including

strip adjustment and ground truth verification, has

produced very good results.“

Great Benefits for Many Organizations

Lantmäteriet uses the geo-referenced point cloud

data to calculate the new digital elevation model.

“The benefits of the project appear to be many. We

have noticed a great interest from potential users

of both the DEM database and of laser data,” says

Gunnar Lysell. “The data can be used for almost any-

thing. We expect all Swedish Municipalities will use it

for their planning of new infrastructure and for flood

protection planning.” The data can also be import-

ed into GIS software suites and advanced software

packages to simulate floods for future infrastructure

planning. “The forestry industry will definitely use

the laser data for investigations on the wood yield of

Swedish forests,” continues Lysell, “and even Swed-

ish orienteering clubs will use it for production of

orienteering maps.”

For public authorities, municipal and governmental,

the elevation data will be available as part of the

European wide “Inspire” project. “When the new

data is available to end users, we will publish refer-

ences on our website to various applications where

the data is being used,” concludes Gunnar Lysell. Of

course, Lantmäteriet will use the data to update their

orthophoto production and to put height values on

cartographic features mapped in 2D.

Visualizing Historical

Shorelines

A first processing of the data has disclosed patterns

of historical shorelines after hiding the vegetation.

“These shorelines are remains of the raised sea

level after the last ice period some 10,000 years

ago. Ice melting caused an uplift of the land, up to

almost 300 m in some parts of Sweden,” explains

Lysell. “Before the new, accurate elevation data, this

pattern could only be found through field research,

but now we can see it easily by viewing the eleva-

tion model on our computer screens.” The old eleva-

tion model with 50 m grid and a height accuracy of

approximately ± 2 m could not resolve the patterns.

Even today, the land is still rising at a rate of approxi-

mately 1 cm per year in the central part of Sweden.

26 | Reporter

by Geoff Jacobs

With a population of over 12 million, Istanbul

is the world’s 5th largest city. Its rolling terrain,

rich architecture, and Bosporus Strait views also

make it one of the most magnificent. In 2003,

UNESCO designated large portions of the histor-

ic Istanbul peninsula as protected areas. All fur-

ther development of these areas was stopped

until a detailed and highly accurate as-built 3D

city model could be created for use by the city

planning commission. It was urgent to complete

the 3D city model as quickly as possible to lift

the moratorium on development.

The need to create the model quickly and with high

accuracy triggered the largest terrestrial scanning

project ever undertaken: 48,000 buildings (11,000

of which had great historic importance), 1,500 hect-

ares, 5.5 million m² of facade, and 400 km of city

streets. Included in this project was the creation of

highly accurate and detailed 3D models of many cul-

tural landmarks, including the famous Topkapi Palace

and Hagia Sophia mosque.

The project was conducted by IMP – BİMTAŞ, the

Istanbul Metropolitan Municipality’s Directory of the

Protection of Historical Environment. Over a period

of 18 months it involved approximately 120 field &

office staff and five Leica Geosystems HDS scanners,

including one in mobile mode.

Requirements

Requirements of 1/500 and 1/200 scale for the first

and second degree protection areas were critical.

This translated into a requirement of 2 cm point den-

sity for scanning facades. Landmarks, such as the

Süleymaniye mosque, required an even higher scan

density of 5 – 10 mm. All scan data had to be geo-

referenced for use in a city-wide GIS. Of course, the

other critical requirement was the 18-month sched-

ule.

After the data was collected, three types of deliver-

ables were required. One was a 3D wire frame model

of all of the external building facades and walls. For

cultural landmarks, fully textured 3D models were

required. For key city landmarks a third type of deliv-

erable was needed: a physical, solid 3D model made

Modeling Istanbul: World’s Largest Scanning Project

Scanning the Suleymaniye Mosque required a long-

range, high-accuracy Leica Geosystems laser scanner.

scan speeds > 125,000 points/sec. Scans were reg-

istered and tied to control using scan targets placed

on tripods, facades, or other convenient locations.

Control points were surveyed with total stations.

For cultural landmarks, BİMTAŞ turned to Leica

Geosystems’ versatile, high accuracy time-of-flight

scanner (HDS3000). Although not as fast as phase-

based scanners, this scanner was needed to achieve

high-accuracy (6 mm), high-density (5 – 10 mm spac-

ing) scan data at long ranges. The Süleymaniye

mosque, for example, features a 76 m minaret and

55 m dome.

As the project progressed, it became apparent

that even with four static phase-based scanners,

the schedule for the mammoth undertaking was in

jeopardy. To remedy this, BİMTAŞ secured the sys-

tem integration services of VisiMind from Sweden

to develop a mobile scanning system for one of the

phase-based scanners. BİMTAŞ was able to scan

while driving up to 5 km/h in the crowded city streets

and still achieve the required accuracy and 2 cm point

density.


from computer models by a 3D printing device. These

“exact replica” models are used on official occasions

by city personnel.

Field Methodology

To accomplish the data collection of the building

facades in the city’s narrow and crowded streets,

BIMTAS used four short-range, Leica HDS phase-

based scanners (HDS4500) on tripods. Each featured

>>

All laser scan data were accurately geo-referenced.

3D point clouds of facades along Suleymaniye Kirazli Mescit street.

Happy Clients and More Customers

Working with a highly accurate 3D city model, Istan-

bul city planners were extremely pleased. Prior to

this, they made important planning and zoning deci-

sions based solely on 2D drawings and photos. With

an accurate 3D model, they can better visualize pro-

posed projects, overlaying them in 3D against the

current city model. In particular, they can assess

the impact of proposals on views across the city’s

many beautiful areas. Another big plus is their ability

to accurately account for the rolling terrain and its

impact on views affected by new proposals.

The Istanbul 3D City Modeling project was so success-

ful that BİMTAŞ has received similar requests from

other cities for their scanning and modeling services

and executed additional projects with impressive and

valuable results.

About the author:

Geoff Jacobs is Senior Vice President, Strategic Mar-

keting, for Leica Geosystems’ HDS business.

28 | Reporter

Deliverables

After the scan data was cleaned, registered, and

geo-referenced (in Leica Cyclone Register software),

office staff worked within a custom 3D CAD environ-

ment to create the final 3D wire frame CAD deliv-

erables, including detailed stonework. These CAD

models were, in turn, combined with high resolu-

tion photographs in 3D Studio Max to create final,

textured models of stunning visual quality, all with

2 – 3 cm overall accuracy.


time the surveyor needs to know exactly how much

the building is offset from its design position and at

the same time he must know the precise position

at the instrument location. Construction vibrations

in the building and building movement further com-

plicate this situation, making it very difficult, if not

impossible, to keep an instrument leveled up.

Leica Geosystems has developed and tested a sur-

veying system, the Core Wall Control Survey System

(CWCS), using networked GNSS (GPS and GLONASS)

sensors combined with high precision inclination sen-

sors and total stations to deliver precise and reliable

coordinates on demand that are referenced to the

design frame, where the construction was designed

and projected, and that are not influenced by build-

ing movements. These coordinates are used to con-

trol the position of the climbing formwork systems

located at the top of any vertical structure, such as a

tall building under construction, as well as to monitor

the dynamics and behavior of the structure imple-

mented.

Active Control Points and

Inclination Sensors

As on most construction sites, surveyors typically

work around steel structures and obstructions and

beneath or beside materials being lowered by crane.

The working areas are congested with materials,

Controlling Vertical Towers

by Joël van Cranenbroeck

There has been considerable interest in the con-

struction of super high-rise and iconic buildings

recently. From a surveying perspective, these

towers present many challenges. The Burj Khal-

ifa in Dubai and the Al Hamra tower in Kuwait,

for example, have risen into territory previously

uncharted: methods and processes normally

used to control tall buildings have needed a re-

think. Leica Geosystems’ Core Wall Control Sur-

vey System (CWCS) delivers precise and reliable

coordinates on demand that are not influenced

by building movements.

In addition to being very tall, high-rise buildings are

often quite slender and during construction there is

usually a lot of movement of the building at upper

levels due to wind loads, crane loads, construction

sequence, and other factors. It is essential that a

straight “element” be constructed that, theoretically,

moves around its design center point due to varying

loads and, if all conditions were neutral, would stand

exactly vertical. This ideal situation is rarely achieved

due to differential raft settlement, differential con-

crete shortening, and construction tolerances.

Structural movement creates several problems for

correct set-out of control: at a particular instant in >>

Burj Khalifa in Dubai (828 m)

30 | Reporter

equipment, and people, and of course working at

height requires a special regard for safety. Under

these conditions surveying becomes difficult.

In time, surveying becomes very much a steering of

the vertical alignment of every single wall element by

making discrete corrections to the position of each,

but with strict limitations placed on the amount of

correction per rise. This needs to be done while the

structure continues to move as usual. The optimum

method for placing survey control for tall buildings

needs much consideration. The use of conventional

methods such as optical plumbing of control through

slab penetrations is very limited for such structures.

Core walls are constructed in a sequence of several

concrete pours. After each pour, three to four GNSS

antennas combined with a GNSS permanent refer-

ence station and a total station are set up. The total

station observes the geometry of the GNSS antennas

by measuring angles and distances to the 360° col-

located reflectors (Active Control Points). This infor-

mation and the GNSS data are either post-processed

at the survey office or calculated in real-time on site.

The resulting coordinates are transferred to the total

station to update its coordinates and orientation.

Precise dual-axis inclination sensors are installed at

ground level and at about every given number level

above. The information from the inclination sen-

sors is logged at the survey office and the exact

amount in Δx and Δy that the building is offset from

its vertical position is applied as corrections to the

coordinates of the Active Control Points. The total

station then observes the control points (nails set in

the top of the concrete) to derive the corrections to

be applied to the formwork structure. These coor-

dinates are in relation to a continuous line of the

building as defined by the control lines and therefore

when the points are used to set the formwork for the

next pour, the construction progresses as a straight

element regardless of building movement.

From WGS to Gravity Vertical

All the results from GNSS surveying refer to an ellip-

soidal normal as reference for the Z component

(WGS84). Therefore a transformation is carried out

to transform the results obtained by GNSS to the

same local coordinate reference frame as the prima-

ry survey control network. If this transformation is

limited to a single point, the difference between the

gravity vertical (that could be visualized by a plumb

line) and the ellipsoid normal (deflection of the verti-

cal) will introduce a bias that will impact the vertical

alignment of the construction. The transformation

needed to get GNSS to provide coordinates and ori-

entation for the total station is derived by using the

coordinates of the reference frame and the coordi-

nates obtained for the same marks with GNSS.

To summarize, GNSS receivers, automatic total sta-

tions, and precise inclinometers must all refer to the

same reference frame, where the gravity vertical is

the most sensitive component as the building’s main

axis reference.

Benefit

The real advantage is that the surveyor is able to

continue to set control – even when the building has

moved “off centre” – confident that he will construct

a straight concrete structure. With the networked

dual-axis precise inclination sensors he also obtains

precise information about building movement.

The analysis isolates factors such as wind load, crane

loads, and raft slab deformation and also relates

movement to the construction sequence. This infor-

mation is of great benefit in explaining to the client


what is actually happening to the structure. If there

is a trend in any one direction it can be identified and

an RFI (request for information) submitted for a cor-

rection based on reliable data obtained over a long

period of time.

Another advantage is that the surveyor is able to

get precise positions at the top of the formwork

without the need of sighting external control marks,

which become increasingly difficult to observe as the

building rises. The control surveys are completed in a

shorter time, improving productivity, and the instru-

ments do not need to be leveled during the survey,

which is an important consideration when the build-

ing is moving or there are vibrations.

A Tribute to Chief Surveyors and

Structural Engineers

Doug Hayes, an Australian surveyor who worked on

a number of large construction projects world-wide

and was Chief Surveyor at Samsung Engineering &

Construction, United Arab Emirates, immediately rec-

ognized the merit of Leica Geosystems’ Core Wall

Survey Control System proposal and largely contrib-

uted to the success of its implementation during the

construction of Burj Khalifa in Dubai.

A short time after the installation of the CWCS in

Dubai we were contacted about the Al Hamra tower

project in Kuwait. The contractor was requesting a

similar system and a professional surveyor that would

be able to drive it. Soang Hoon from South Korea

was willing to accept the challenge and became Chief

Surveyor for the contractor. Even though the system

was similar to the one delivered for the Burj Khalifa,

he made necessary adaptations and we learnt how

tall buildings are different even if, from a surveying

point of view, they have the same specifications.

A year after the installation in Kuwait, we were asked

to provide a CWCS system for the Landmark tower

in Abu Dhabi. This tower was again slightly different

and the contractor had great interest in having the

system run in real-time mode. Mohammed Haider,

structural engineer for the contractor, oversees the

system and has been an outstanding supporter.

In this article I tried to review the state of the art

of an innovative surveying method to support the

construction of outstanding vertical structures. The

dedicated involvement of the surveyors and engi-

neers in this process has contributed greatly to the

sophistication of our system. In the near future we

would not be surprised to receive requests for semi

or fully automatic systems. After all, it is only the

first step in a long journey.

About the author:

Joël van Cranenbroeck is Business Development Man-

ager for Leica Geosystems, Heerbrugg, Switzerland

Australia

CR Kennedy & Company Pty Ltd.

Melbourne

Phone +61 3 9823 1555

Fax +61 3 9827 7216

Austria

Leica Geosystems Austria GmbH

Vienna

Phone +43 1 981 22 0

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Belgium

Leica Geosystems NV

Diegem

Phone +32 2 2090700

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Brazil

Comercial e Importadora WILD Ltda.

São Paulo

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Canada

Leica Geosystems Ltd.

Willowdale

Phone +1 416 497 2460

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Beijing

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Herlev

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Espoo

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France

Leica Geosystems Sarl

Le Pecq Cedex

Phone +33 1 30 09 17 00

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Germany

Leica Geosystems GmbH Vertrieb

Munich

Phone + 49 89 14 98 10 0

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Hungary

Leica Geosystems Hungary Kft.

Budapest

Phone +36 1 814 3420

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India

Elcome Technologies Private Ltd.

Gurgaon (Haryana)

Phone +91 124 4122222

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Italy

Leica Geosystems S.p.A.

Cornegliano Laudense

Phone + 39 0371 69731

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Japan

Leica Geosystems K.K.

Tokyo

Phone +81 3 5940 3011

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Korea (Republic of)

Leica Geosystems KK

Seoul

Phone +82 2 598 1919

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Mexico

Leica Geosystems S.A. de C.V.

Mexico D.F.

Phone +525 563 5011

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Netherlands

Leica Geosystems B.V.

Wateringen

Phone +31 88 001 80 00

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Norway

Leica Geosystems AS

Oslo

Phone +47 22 88 60 80

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Poland

Leica Geosystems Sp. z o.o.

Warsaw

Phone +48 22 260 50 00

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Portugal

Leica Geosystems, Lda.

Moscavide

Phone +351 214 480 930

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Singapore

Leica Geosystems Techn. Pte. Ltd.

Singapore

Phone +65 6511 6511

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South Africa

Hexagon Geosystems Pty.Ltd.

Douglasdale

Phone +27 1146 77082

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Spain

Leica Geosystems, S.L.

Barcelona

Phone +34 934 949 440

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Sweden

Leica Geosystems AB

Sollentuna

Phone +46 8 625 30 00

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Switzerland

Leica Geosystems AG

Glattbrugg

Phone +41 44 809 3311

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United Kingdom

Leica Geosystems Ltd.

Milton Keynes

Phone +44 1908 256 500

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UAE

Leica Geosystems c/o Hexagon

Dubai

Phone +971 4 299 5513

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USA

Leica Geosystems Inc.

Norcross

Phone +1 770 326 9500

Fax +1 770 447 0710

Illustrations, descriptions, and technical data are not binding. All rights reserved. Printed in Switzerland.

Copyright Leica Geosystems AG, Heerbrugg, Switzerland, 2010. 741802en – IX.10 – RVA

www.leica-geosystems.com

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