realization of etrs89 in greece by the hepos network twg minutes/53-gavle2010/05... · igs final...

KTIMATOLOGIO S.A.

Realization of ETRS89 in Greece by the Realization of ETRS89 in Greece by the HEPOS networkHEPOS network

53th EUREF TWG Meeting, Gävle, June 1, 2010

M. Gianniou

KTIMATOLOGIO S.A.KTIMATOLOGIO S.A. (Hellenic Cadastre)

Geodetic Department

[email protected]

1. HEPOS Project

2. Densification project

3. Initial and recent solution

Initial solution

OutlineOutline


4. Initial solution

5. Recent solution

6. Comparison of initial and recent solution

1. HEPOS Project1. HEPOS Project

Framework of establishment

• part of the project “Information and Technology Infrastructure for a modern Cadastre”

• a CSF-III project, co-funded by the European Regional Development Fund


• HEPOS was deployed in 2007, in less than 12 months

• supports other CSF-III projects, i.e. production of orthophoto maps for whole Greece

1. HEPOS Project1. HEPOS Project

98 Reference stations:


98 Reference stations:

• 87 supporting network- based techniques(VRS - FKP - MAC)

• 11 for Single- base

positioning

2. Densification project2. Densification project

GLSV

GRAZ

JOSE

WTZR

113 stations

EPN

Total 14

Class A 1313

In the densi-

fication zone

3


NICO

TRAB

ANKR

RAMO

MATE

NOT1

ORID

TUC2

NOA1

AUT1

fication zone

HEPOSHEPOS

Total 99(98+1)

4-char ID Full Name Country Domes No. Network

1 GLSV KIEV UKRAINE 12356M001 EPN class A, IGS

2 JOZE JOZEFOSLAW POLAND 12204M001 EPN class A, IGS

3 MATE MATERA ITALY 12734M008 EPN class A, IGS

4 NICO NICOSIA CYPRUS 14302M001 EPN class A, IGS

5 NOT1 NOTO ITALY 12717M004 EPN class A, IGS


EPN stations


5 NOT1 NOTO ITALY 12717M004 EPN class A, IGS

6 TRAB TRABZON TURKEY 20808M001 EPN class B, IGS

7 WTZR BAD KOETZTING GERMANY 14201M010 EPN class A, IGS

8 RAMO MITZPE RAMON ISRAEL 20703S001 EPN class A, IGS

9 ANKR ANKARA TURKEY 20805M002 EPN class A, IGS

10 GRAZ GRAZ AUSTRIA 11001M002 EPN class A, IGS

11 AUT1 THESSALONIKI GREECE 12619M002 EPN class A

12 NOA1 ATHENS GREECE 12620M001 EPN class A

13 TUC2 CHANIA GREECE 12617M003 EPN class A

14 ORID OHRID FYROM 15601M001 EPN class A, IGS


HEPOS stations

Equipment Model IGS code

All HEPOS stations are equipped with the same GPS equipment


Receivers Trimble NetRS TRIMBLE NETRS

Antennas Trimble Zephyr geodetic TRM41249.00

Domes Trimble spherical TZGD


HEPOS stations

All HEPOS antennas are mounted on steel masts

On roof of buildings or On side of buildings



HEPOS stations

All HEPOS antennas are mounted on the frame of the building (reinforced concrete )



Observations used

14 days of observations (7-20 October 2007)

3 additional days (17-19 November 2007)


3 additional days (17-19 November 2007) to include in the solution station 018B, which replaced station 018A.

3. Initial and recent solution3. Initial and recent solution

Initial solutionInitial solution

• Computed: December 2007

• ETRF2005 (current frame at that time)

• coordinates used for the HEPOS stations since HEPOS is operable

Recent solution Recent solution


Recent solution Recent solution

• Computed: May 2010

• Follows the latest EUREF standards, i.e.:

• “Specifications for reference frame fixing in the analysis of a EUREF GPS

campaign” Ver. 7, 24/10/2008

• “Guidelines for EUREF Densifications”, Ver. 1, 26/05/2009

• ETRF2000

4. Initial solution4. Initial solution

4-char ID Country Network Comments

1 AUT1 GREECE EPN class A fiducial

2 ANKR TURKEY EPN class A, IGS validation point

3 GLSV UKRAINE EPN class A, IGS validation point

4 GRAZ AUSTRIA EPN class A, IGS validation point

5 JOZE POLAND EPN class A, IGS validation point

6 MATE ITALY EPN class A, IGS validation point

Fiducial and validation points


6 MATE ITALY EPN class A, IGS validation point

7 NICO CYPRUS EPN class A, IGS validation point

8 NOA1 GREECE EPN class A validation point

9 NOT1 ITALY EPN class A, IGS validation point

10 ORID FYROM EPN class A, IGS validation point

11 RAMO ISRAEL EPN class A, IGS validation point

12 TRAB TURKEY EPN class B, IGS validation point

13 TUC2 GREECE EPN class A validation point

14 WTZR GERMANY EPN class A, IGS validation point

Note: At the time of computing the “HEPOS_initial” solution, there was no classification of

the EPN stations. The class given in this table refers to the status at the time of writing.


Coordinates of fiducial points

Coordinates and velocities used for AUT1 (from EUREF site)

ITRF2005 2000.04466283.4880

± 0.0030

1896166.7750

± 0.0020

4126096.7730

± 0.0030

-0.0126

± 0.0005

0.0213

± 0.0002

0.0028

± 0.0005


Computed Coordinates for AUT1 (at tc = 2007.79)

ITRF2005 2000.79 4466283. 3898 1896166. 9409 4126096. 7948


Datum definition (ITRF2005)

Minimal constraints, i.e. by fixing the coordinates of AUT1.

AUT1 is used to compute transformation parameters from ITRF2005 to

ETRF2005. For this reason AUT1 is also used for constraining the solution in

ITRF2005.


An important advantage of AUT1 is that it shows the smallest velocity among the

Greek EPN stations and could ensure maximum consistency between HTRS07

and ETRS89 in the northern part of Greece, i.e. on the borders between Greece

and the other European countries.


Processing parameters

Software used

Bernese 5.0

Processing Agency

IGN-Spain *


IGN-Spain *

* KTIMATOLOGIO S.A. procured the establishment of HEPOS as a turn-key solution including

the computation of the station coordinates. This task was assigned by the contractor (Trimble Europe B.V.) to IGN-Spain.


Orbits and ERPs

IGS final orbit and ERP information

Antenna calibrations – stations

Absolute antenna phase center corrections based on IGS05 model



Absolute antenna phase center corrections based on IGS05 model

(exceptions for stations with individual absolute calibrations listed in

epnc_05.atx) considering antenna radome codes.

Antenna calibrations – satellites

Absolute antenna phase centre corrections based on IGS05 model

calibrations



Preprocessing

Phase preprocessing in a baseline by baseline mode using triple

differences. In most cases cycle slips are fixed looking simultaneously at

different linear combinations of L1 and L2. If a cycle slip cannot be fixed


different linear combinations of L1 and L2. If a cycle slip cannot be fixed

reliably, bad data points are removed or new ambiguities are set up.

Basic Observable

Carrier phase, code only used for receiver clock synchronization.



Elevation angle cutoff

3 degrees + elevation dependent weighting with cos-z

Data sampling

For ambiguity resolution: 30 s.


For ambiguity resolution: 30 s.

For final processing: 180 s.

Modeled observable

Double-differences, ionosphere-free linear combination.


Troposphere

Dry-Niell as a priori model, estimation of zenith delay corrections at 1hour

intervals for each station, using the wet-Niell MF, no a priori sigmas.

Horizontal gradient parameter estimated/day/station (TILTING), no a



Horizontal gradient parameter estimated/day/station (TILTING), no a

priori constraints. Compute daily TRO files with fixed cumulative.

Coordinates input from weekly solution.

Ionosphere

Regional ionospheric model calculated. Only used for QIF ambiguity

resolution. Not modeled in final solution (ionosphere eliminated by forming

the ionosphere-free linear combination of L1 and L2).


Estimated parameters

Adjustment

Weighted least-squares algorithms.

Rejection Criteria

Daily RINEX observation files containing less than 10 percent of possible


Daily RINEX observation files containing less than 10 percent of possible

observation are ignored. The threshold value concerning data screening is

2.5 mm, specifically for a normalized, or L1 zero difference zenith residual.

Station where baseline data exceeding the overall sigma level of 5

millimeters is excluded.



Troposphere

Absolute constraints: 5.0 m, Relative constraints: 5.0 m.

Ionosphere

Regional ionospheric model for QIF ambiguity resolution.


Regional ionospheric model for QIF ambiguity resolution.

Ambiguity resolution

Ambiguity resolution is performed by using the quasi-ionosphere-free

(QIF) strategy with regional TEC information. Elevation angle cutoff: 10

degrees.



Satellite clock bias

Satellite clock biases are not estimated but eliminated by forming double-

differences.

Receiver clock bias


Receiver clock bias

Receiver clock corrections are estimated as part of the biases

preprocessing using code measurements. They are finally eliminated by

forming double differences.



Planetary Ephemeris

DE200

Tidal effects

Solid earth tidal displacements are modeled according to IERS


Solid earth tidal displacements are modeled according to IERS

conventions 1996.

Ocean loading

Using model computed by H.G.Scherneck Onsala Space Observatory

FES2004 model for each station.

Atmospheric loading

No atmospheric loading corrections are taken into account.


Repeatabilities (North)

repeatabilities N (mm)

3

4


0

1

2

AN

KR

MA

TE

RA

MO

00

2A

00

7A

01

2A

01

7A

02

1A

02

6A

03

1A

03

6A

04

1A

04

6A

05

1A

05

6A

06

1A

06

6A

07

1A

07

6A

08

1A

08

6A

09

1A

09

6A


Repeatabilities (East)

repeatablities E (mm)

3

4


0

1

2

AN

KR

MA

TE

RA

MO

00

2A

00

7A

01

2A

01

7A

02

1A

02

6A

03

1A

03

6A

04

1A

04

6A

05

1A

05

6A

06

1A

06

6A

07

1A

07

6A

08

1A

08

6A

09

1A

09

6A


Repeatabilities (Up)

repeatabilities U (mm)

6

7

8

9


0

1

2

3

4

5

6

AN

KR

MA

TE

RA

M

00

2A

00

7A

01

2A

01

7A

02

1A

02

6A

03

1A

03

6A

04

1A

04

6A

05

1A

05

6A

06

1A

06

6A

07

1A

07

6A

08

1A

08

6A

09

1A

09

6A


Stn DX (mm) DY (mm) DZ (mm)

ANKR -1.7 -6.6 2.7

AUT1 1.7 -3.1 3.0

GLSV 6.0 -4.8 7.6

Stn North (mm) East (mm) Up (mm)

ANKR 5.0 -5.2 -2.4

AUT1 3.4 -3.2 2.0

GLSV 2.6 -7.4 6.9

In XYZ In NEU

Comparison of ITRF2005/2007.786 coordinates: initial solution vs. EUREF solution (EPN_A_ITRF2005_C1570)


GLSV 6.0 -4.8 7.6

GRAZ 5.8 -2.3 4.2

JOZE 6.4 -3.3 5.5

MATE -0.4 -5.4 -0.3

NICO -2.6 -6.1 6.0

NOA1 -3.7 -7.4 -2.7

NOT1 -1.1 -4.0 -0.5

ORID 3.0 -4.3 -0.2

RAMO -8.1 -8.6 -1.5

TUC2 -2.2 -5.5 -1.1

WTZR 6.2 -2.5 4.3

GLSV 2.6 -7.4 6.9

GRAZ -0.5 -3.7 6.1

JOZE -0.8 -5.0 6.5

MATE 0.8 -4.8 -1.7

NICO 8.1 -3.8 -1.5

NOA1 2.1 -5.0 -6.8

NOT1 0.9 -3.6 -2.0

ORID -0.9 -5.2 0.1

RAMO 4.6 -2.6 -11.5

TUC2 1.2 -4.6 -4.0

WTZR -1.5 -3.9 7.4


Transformation to ETRS89

At the time realization of HTRS07, version 6 of the B/A memo was valid.




At the time of realization of HTRS07, no velocities were available for the HEPOS stations.

Furthermore, the velocity field in Greece is complex and inhomogeneous. The velocities of the Greek stations differ strongly among each other.


Any application of individual velocities would distort the homogeneity of the HEPOS network.

For these reasons, no transformation to t = 1989.0 was done.

Note: According to the current version of the B/A memo (version 7) “it is no

longer recommended to propagate the station coordinates by means of

whatever intra plate velocities to other epoch than the central epoch tc of the

used”

� Use EUREF coordinates and velocities to compute ECEF coordinates of AUT1 in:

- ITRF05/2007.79 (central epoch for HEPOS network adjustment)

- ETRF05/2007.5 (central epoch of the HEPOS GPS campaign for the

computation of transformation model)




computation of transformation model)

� Compute the translation components ∆Χ, ∆Υ and ∆Ζ between the above ECEF coordinates of AUT1

� Use of the above translation parameters to transform all HEPOS stations from ITRF05/2007.79 to ETRF05/2007.5.



Coordinates and velocities used for AUT 1 (from EUREF site)

ITRF2005 2000.04466283.4880

± 0.0030

1896166.7750

± 0.0020

4126096.7730

± 0.0030

-0.0126

± 0.0005

0.0213

± 0.0002

0.0028

± 0.0005

ETRF2005 2000.04466283.7370

± 0.0030

1896166.6250

± 0.0020

4126096.6180

± 0.0030

0.0049

± 0.0005

0.0033

± 0.0002

-0.0079

± 0.0005


Resulting coordinates for AUT1 and transformation parameters

ITRF2005/2007.79 ETRF2005/2007.50 Translation parameters from ITRF2005/2007.79 to ETRF2005/2007.50*

X = 4466283. 3898 X = 4466283.7737 DX = 0.3839

Y = 1896166. 9409 Y = 1896166.6497 DY = -0.2912

Z = 4126096. 7948 Z = 4126096.5587 DZ = -0.2361

* Epoch 2007.500 was chosen, as it was the central epoch of the national GPS campaign carried-out

for the computation of a transformation model between HTRS07 and the National coordinate system HGRS87

Fiducial points

5. Recent solution5. Recent solution

4-char ID Country Network Comment

1 AUT1 GREECE EPN class A In the densification zone

2 ANKR TURKEY EPN class A, IGS

3 GLSV UKRAINE EPN class A, IGS

4 GRAZ AUSTRIA EPN class A, IGS

5 JOZE POLAND EPN class A, IGS


5 JOZE POLAND EPN class A, IGS

6 MATE ITALY EPN class A, IGS

7 NICO CYPRUS EPN class A, IGS

8 NOT1 ITALY EPN class A, IGS

9 NOA1 GREECE EPN class A In the densification zone

10 ORID FYROM EPN class A, IGS

11 RAMO ISRAEL EPN class A, IGS

12 TUC2 GREECE EPN class A In the densification zone

13 WTZR GERMANY EPN class A, IGS


Coordinates of fiducial points

Stn

Data Start - Data End

DOY/year - DOY/year X Y Z Vx Vy Vz X Y Z

ANKR 309/2006 - 131/2008 4121948.539 2652187.914 4069023.767 -0.0080 -0.0045 0.0084 4121948.5164 2652187.9013 4069023.7908

Computed coordinates at tc = 2007.83Coordinates and velocities at to = 2005.00 (EPN_A_ITRF2005_C1570)

The ITRF2005/2007.83 coordinates of the fiducial points were computed using solution C1570.


AUT1 309/2006 - 044/2010 4466283.433 1896166.881 4126096.790 -0.0149 0.0204 0.0028 4466283.3908 1896166.9387 4126096.7979

GLSV 309/2006 - 312/2007 3512888.957 2068979.880 4888903.212 -0.0190 0.0141 0.0091 3512888.9032 2068979.9199 4888903.2378

GRAZ 309/2006 - 044/2010 4194423.823 1162702.697 4647245.416 -0.0167 0.0176 0.0108 4194423.7757 1162702.7468 4647245.4466

JOZE 309/2006 - 044/2010 3664940.167 1409153.865 5009571.389 -0.0173 0.0153 0.0098 3664940.1180 1409153.9083 5009571.4167

MATE 309/2006 - 334/2008 4641949.555 1393045.429 4133287.461 -0.0176 0.0189 0.0155 4641949.5052 1393045.4825 4133287.5049

NICO 077/2007 - 044/2010 4359415.718 2874117.073 3650777.826 -0.0193 0.0105 0.0123 4359415.6634 2874117.1027 3650777.8608

NOA1 309/2006 - 044/2010 4599641.930 2034827.315 3909890.640 0.0030 0.0093 -0.0094 4599641.9385 2034827.3413 3909890.6134

NOT1 309/2006 - 044/2010 4934546.229 1321265.012 3806456.119 -0.0186 0.0169 0.0150 4934546.1764 1321265.0598 3806456.1615

ORID 212/2000 - 293/2007 4498451.692 1708266.984 4173591.865 -0.0149 0.0202 0.0095 4498451.6498 1708267.0412 4173591.8919

RAMO 309/2006 - 044/2010 4514721.846 3133507.840 3228024.701 -0.0210 0.0131 0.0181 4514721.7866 3133507.8771 3228024.7522

TRAB 345/2006 - 331/2007 n/a n/a n/a n/a n/a n/a - - -

TUC2 309/2006 - 044/2010 4744543.776 2119411.896 3686258.843 0.0027 0.0098 -0.0103 4744543.7836 2119411.9237 3686258.8139

WTZR 309/2006 - 024/2009 4075580.558 931853.799 4801568.139 -0.0156 0.0168 0.0103 4075580.5139 931853.8465 4801568.1681


Datum definition (ITRF2005)

Using minimal constraints, to compute three translation parameters on the network´s barycentre.

This strategy has the advantage that small errors in the coordinates do


This strategy has the advantage that small errors in the coordinates do

neither distort the network geometry nor significantly degrade the datum

definition per se.



The processing parameters and the repeatabilities are the same like in the Initial solution.


in the Initial solution.


Comparison of ITRF2005/2007.83 coordinates: recent solution vs. EUREF solution (EPN_A_ITRF2005_C1570)

In XYZ In NEU

Stn North (mm) East (mm) Up (mm)

ANKR 2.8 -0.2 -1.8

AUT1 -0.2 2.0 3.0

GLSV 0.4 -1.8 7.2

Stn DX (mm) DY (mm) DZ (mm)

ANKR -2.6 -1.8 1.2

AUT1 1.3 2.9 1.9

GLSV 4.5 0.8 5.9


GLSV 0.4 -1.8 7.2

GRAZ -2.0 2.0 5.0

JOZE -2.0 0.2 5.8

MATE -0.2 0.6 -2.8

NICO 5.8 1.6 -0.6

NOT1 -0.4 2.2 -3.4

NOA1 -1.0 0.0 -6.8

ORID -2.8 0.6 0.2

RAMO 2.6 3.0 -9.2

TUC2 -1.2 1.0 -4.0

WTZR -2.4 1.8 5.0

GLSV 4.5 0.8 5.9

GRAZ 4.0 3.3 2.4

JOZE 4.5 2.1 3.3

MATE -2.2 0.2 -1.9

NICO -4.1 -0.7 4.6

NOT1 -4.3 -2.0 -5.1

NOA1 -3.0 1.5 -2.2

ORID 1.5 1.5 -1.9

RAMO -9.4 -2.8 -2.4

TUC2 -2.7 -0.2 -3.4

WTZR 4.4 3.0 2.3



The transformation of the ITRF2005/2007.83 coordinates to ETRF2000/2007.83 was done using the EPN web page tool.


ETRF2000/2007.83 was done using the EPN web page tool.

6. Comparison of initial and recent solution6. Comparison of initial and recent solution

Comparison of ETRS89 coordinates: Initial solution vs. recent solution

2

4

D North (mm)


-14

-12

-10

-8

-6

-4

-2

0

2

001A

006A

011A

016A

020A

025A

030A

035A

040A

045A

050A

055A

060A

065A

070A

075A

080A

085A

090A

095A



D East (mm)

-4-202


-28-26-24-22-20-18-16-14-12-10-8-6-4

001A

006A

011A

016A

020A

025A

030A

035A

040A

045A

050A

055A

060A

065A

070A

075A

080A

085A

090A

095A



D Up (mm)

0

10


-40

-30

-20

-10

0

001A

006A

011A

016A

020A

025A

030A

035A

040A

045A

050A

055A

060A

065A

070A

075A

080A

085A

090A

095A



Statistics

DN (mm) DE (mm) DS (mm) DU (mm)

Max |D| 13.4 26.0 27.4 39.8


Max |D| 13.4 26.0 27.4 39.8

Mean D - 4.7 - 17.5 - 19.4

Mean |D| 5.2 17.5 18.5 19.9

Conclusion: The two solutions are consistent to a few centimeters: • Maximum differences do not exceed 3 cm (horizontal) and 4 cm (vertical). • Mean differences are below 2 cm both in the horizontal and in the vertical component.

IGN-Spain for the computation of the HEPOS network.

Prof. K. Katsampalos and C. Kotsakis (AUTH: Aristotle University of Thessaloniki) for assisting KTIMATOLOGIO SA in the definition HTRS07 and the computation of coordinate transformation model.

The chair and the members of EUREF-TWG for their valuable

Acknowledgments Acknowledgments


The HEPOS project is part of the Operational Program “Information Society” and is co-funded by the European Regional Development Fund.

The chair and the members of EUREF-TWG for their valuable comments in the preparation of the report.

realization of etrs89 in greece by the hepos network twg minutes/53-gavle2010/05... · igs final...

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