History of GPS

Global Positioning System more commonly referred to as GPS is a state of the art satellite location mapping technology that was invented by Roger Easton Ivan Getting, Colonel Brad Parkinson, James Buisson, Thomas McCaskill, Don Lynch, Mel Birnbaum, Bob Rennard, Jim Spilker, Charles A. Bartholomew and Randolph Zirn for the US Army back in 1972 while working on a platform that would make it easier for the US to track and direct their ships, deploy smart bombs and troops to pinpointed locations without harm or danger in the most covert manner possible. The idea was the brainchild of Ivan Getting in the 1950’s and patented by Roger Easton in 1974. The overall effort was a combining one from several committees and compromises that cost about $12Billion to initiate and follow through. A study in the early 60’s examined what was needed in a satellite-based navigation system and proposed that it support high-performance aircraft operations, including blind bombing where one could bomb n the toughest weather and still hit a target due to electronic means, provide absolute positioning and relative positioning within 0.01 nautical mile; and be user-passive. It also stipulated that user equipment weigh less than 100 pounds and fairly cheap. From the beginning, military applications such as bombing, missile guidance, navigation of ships, and coordination of ground forces were part of the planning. Within the government, civil use of GPS for similar functions, such as commercial aircraft guidance, were recognized as potential outcomes. The 1980 Federal Radio navigation Plan acknowledged the potential for both civil and military users, but envisioned a system in which the civil function is limited and constrained by national security.

Although the use of GPS by the civilian, commercial, and scientific communities was anticipated at the outset, no one anticipated the widespread integration of low-cost chip-sized GPS receivers and precision navigation into everyday life. This was done by removing selective availability ( the signal available for civilian use is intentionally degraded) and expanding the size of the constellation (amount of satellites in orbit at any given moment sending signals back and forth to provide precise location and times. By the 1980s, the only competitor to GPS on the horizon was the Soviet Global Navigation Satellite System (GLONASS). DOD(department of Defence) had not embraced the radical changes in battlefield operations that were to come when GPS, battlefield communications, geographic databases, networked operations, and information operations merged.

Civil Uses of GPS

On the GPS civil side are many visionary and unanticipated applications. While at Stanford University, Bradford Parkinson, former GPS program manager and Aerospace trustee, pioneered the use of GPS for precision operations, such as the unaided landing of an aircraft, precision farming, and the development of Gravity Probe B to explore whether gravity waves affect satellites as Einstein predicted. GPS anklets to track paroled convicts, among other uses, were not envisioned in the 1960s.

Precision farming may seem unnecessary, but consider that when a farmer combines it with soil analyses of a field, fertilizers can be applied exactly where needed in varying amounts, thereby avoiding excessive use of fertilizers that may then drain into waterways. Throughout California, a network of GPS receivers monitor the subtle motions of Earth's tectonic plates and faults. Emergency location features in cellphones make use of GPS, either via a receiver in the phone itself, or via GPS-based timing to accurately synchronize the cell-tower network. Likewise, the banking industry indirectly uses GPS to synchronize the timing for electronic fund transfers. When a customer swipes a credit card at a retailer, GPS may be part of the service.

A two-frequency, precise-positioning service was developed to provide global, all-weather navigation and timing service for the DOD, its allies, and other authorized entities. Even before GPS reached its full operational capability in 1995, the revolutionary impact of precise-positioning-service GPS on military operations had been proven in battle. In Operation Desert Storm, even the partially complete GPS constellation allowed U.S. and coalition armored forces to precisely execute a massive flanking maneuver over featureless desert terrain that would have been unthinkable only a few years before. These large-scale maneuvers were a key reason the ground campaign of Desert Storm was completed in 100 hours, with minimal U.S. and coalition casualties. Desert Storm provided the first real demonstration of the value of GPS to military operations and evidence of its power as a "force multiplier," allowing military objectives to be achieved with smaller forces, fewer casualties, and less collateral damage.

GPS Today

As of 2010, the NAVSTAR Global Positioning System is fully operational, with 31 healthy satellites providing service to civil and military users worldwide. This represents a remarkable success rate, not only in the development and deployment of these space borne devices, but for the launch community as well. Aerospace participated in the launch of the first experimental Block I satellite in February 1978, and in every one of the launch attempts thereafter—60 in all. Of these attempts, 58 have been successful—a remarkable record by any standard. Although they surely had ideas for how the system would be used by both military and civil users, the original architects of GPS could not have envisioned the myriad applications and worldwide acceptance of GPS as the first truly global utility. Parts of their original vision for GPS have become reality, but others have not. What GPS will become during its modernized era cannot be accurately predicted today; however, it can be assumed that GPS will remain an engine of innovation in position, navigation, and timing applications. Many of the best applications of GPS are still to come.

Importance of GPS To Valuers

GPS could also evolve into a surveyor's utility, with little or no use by actual end users. One way this might come about is through the proliferation of millions of local beacons, each surveyed by GPS. Imagine if every highway reflector, every road stripe, every light switch, and every electrical outlet contained a small locater similar to RFID (radio-frequency identification) chips common in employee ID cards, anti shoplifting devices, and new passports. Devices fitted into a watch or a cell phone could identify its proximity to these fixed locators “landmarks" and derive position from this information. For this to work, all the little beacons would have to be surveyed using GPS and similar technology in order for the users to gain access to a network to get necessary information about the beacons themselves.

The birth of one of the first GPS markets for surveying was influenced by a 1984 decision by the Department of Commerce’s National Oceanic and Atmospheric Administration (NOAA)42 to publish the first draft standards in the Federal Register that allowed for the use of GPS data. This seal of approval of GPS data by a civil government agency helped jump start the expansion of the surveying market even while the GPS system was still in development.

By the mid-1980s, commercial GPS equipment aimed at the surveying profession appeared on the market even though only a small number of operating GPS satellites were in orbit. Surveying and time transfer were logical entry points into the market because their applications could accept the limited availability of satellite signals. Surveyors did not need to use their data in real time, but could make observations whenever sufficient satellite signals wereavailable, day or night. GPS surveying offered greater productivity and cost savings over traditional survey methods. With GPS, tasks that normally required several weeks or months to finish could now be completed in a fraction of the time at one-fifth to one-tenth of the cost of conventional surveying. Satellite surveying also helped sustain the commercial market for GPSequipment after the Challenger disaster shut down operations and delayed satellite launches for several years.

The money generated by the survey market boom was also important to the overall development of GPS applications because it enabled U.S. manufacturers to invest in research and development (R&D) on GPS technology. The added R&D investment helped accelerate the development of GPS applications faster than if governments were relied upon to carry out such a task. Surveyors were the first to employ some of the more advanced differential GPS techniques being used today, such as kinematic surveying and real-time carrier phase tracking. Now, ten years after the first standards were published, almost all geodetic standards are based on GPS data. The growth in the GPS survey market opened the way for a number of GPS niche markets such as aviation. Even in these smaller markets, government agencies have contributed to their expansion. For example, the FAA issued performance standards for GPS receivers (Technical Standard Order C129) in 1992. This action allowed manufacturers to build GPS receivers as supplemental navigation aids for aircraft, thereby broadening the range of market opportunities for GPS suppliers. As evidence of this, Trimble, the first company to be awarded the GPS Technical Standard Order certification, signed an agreement with Honeywell in 1995 to cooperate in developing GPS products for the commercial, space, and military aviation markets. This alliance will allow both companies to tap into new GPS markets.

Government export controls have also affected GPS markets. Prior to 1991, most GPS user equipment shipped abroad required individual validated licenses to ensure compliance with various Department of Commerce (DoC) Bureau of Export Administration export control programs. On September 1, 1991, the DoC revised its export list of electronic equipment requiring licenses for shipment abroad. What the DoC essentially did was to make a clear delineation between military and civil GPS user equipment. Under the revised regulations,civilian GPS receivers, other satellite equipment, and telecommunications systems were freed of restrictions and were allowed to be shipped as “general destination items,” although military receivers, GPS null steerable antennas, encryption devices, and certain other components were still treated as “munitions” with strict export restrictions. This liberalization of export controlshelped speed up the U.S. industry’s entry into foreign markets. Today, export markets are important to U.S. GPS manufacturers, making up an average of 45 to 50 percent of overall sales.

GPS ACCURACY CHARTS

The chart below shows the improvement of accuracy rates over a span of years. Chart 1 shows Military usage and Chart 2 shows Civilian usage accuracy.

Chart 1

Chart 2

CHRONOLOGY OF GPS HISTORICAL EVENTS

Date Event

1920s Origins of radionavigation

Early WW II LORAN, the first navigation system to employ timedifference-of-arrival of radio signals, is developed bythe MIT Radiation Laboratory. LORAN was also thefirst true all-weather position-finding system, but isonly two-dimensional (latitude and longitude).

1959 TRANSIT, the first operational satellite-basednavigation system, is developed by the Johns HopkinsApplied Physics Laboratory (APL) under Dr. RichardKirschner. Although Transit was originally intendedto support the U.S. Navy’s submarine fleet, thetechnologies developed for it proved useful to theGlobal Positioning System (GPS). The first Transitsatellite is launched in 1959.

1960 The first three-dimensional (longitude, latitude,altitude) time-difference-of-arrival navigation systemis suggested by Raytheon Corporation in response toan Air Force requirement for a guidance system to beused with a proposed ICBM that would achievemobility by traveling on a railroad system. Thenavigation system presented is called MOSAIC(Mobile System for Accurate ICBM Control). The ideais dropped when the Mobile Minuteman program iscanceled in 1961.

1963 The Aerospace Corporation launches a study on usinga space system as the basis for a navigation system forvehicles moving rapidly in three dimensions; this leddirectly to the concept of GPS. The concept involvesmeasuring the times of arrival of radio signalstransmitted from satellites whose positions areprecisely known. This gives the distances to theknown satellite positions—which, in turn, establishesthe user’s position.

1963 The Air Force begins its support of the Aerospacestudy, designating it System 621B. By 1972, theprogram has already demonstrated operation of a newtype of satellite-ranging signal based on pseudorandomnoise (PRN).

1964 Timation, a Navy satellite system, is developed underRoger Easton at the Naval Research Lab (NRL) foradvancing the development of high-stability clocks,time-transfer capability, and 3-D navigation.Timation’s work on space-qualified time standardsprovided an important foundation for GPS. The firstTimation satellite is launched in May 1967.

1968 DoD establishes a tri-service steering committeecalled NAVSEG (Navigation Satellite ExecutiveCommittee) to coordinate the efforts of the varioussatellite navigation groups (Navy’s Transit andTimation programs, the Army’s SECOR or SequentialCorrelation of Range system). NAVSEG contracted anumber of studies to fine-tune the basic satellitenavigation concept. The studies dealt with some ofthe major issues surrounding the concept, includingthe choice of carrier frequency (L-Band versus CBand),the design of the signal structure, and theselection of the satellite orbital configuration (a 24-hour figure 8s constellation versus “Rotating Y” and“Rotating X” constellation).

1969–1972 NAVSEG manages concept debates between thevarious satellite navigation groups. The Navy APLsupported an expanded Transit while the Navy NRLpushed for an expanded Timation and the Air Forcepushed for an expanded synchronous constellation“System 621B.”

1971 L2 frequency is added to the 621B concept toaccommodate corrections for ionospheric changes.

1971–1972 ` User equipment for the Air Force 621B is tested atWhite Sands Proving Ground in New Mexico. Groundand balloon-carried transmitters simulating satelliteswere used, and accuracies of a hundredth of a miledemonstrated.

April 1973 The Deputy Secretary of Defense determines that ajoint tri-service program be established to consolidatethe various proposed positioning/navigation conceptsinto a single comprehensive DoD system known as theDefense Navigation Satellite System (DNSS). The AirForce is designated the program manager. The newsystem is to be developed by a joint program office(JPO), with participation by all military services.Colonel Brad Parkinson is named program director ofthe JPO and is put in charge of jointly developing theinitial concept for a space-based navigation system.

August 1973 The first system presented to the Defense SystemAcquisition and Review Council (DSARC) is deniedapproval. The system presented to DSARC waspackaged as the Air Force’s 621B system and thereforenot representative of a joint program. Although thereis support for the idea of a new satellite-basednavigation system, the JPO is urged to broaden theconcept to include the views and requirements of allthe services.

December 17, 1973 A new concept is presented to DSARC and approval toproceed with what is now known as the NAVSTARGPS is granted, marking the start of concept validation(Phase I of the GPS program). The new conceptwas really a compromise system negotiated by Col.Parkinson that incorporated the best of all availablesatellite navigation system concepts and technology.The approved system configuration consists of 24satellites placed in 12-hour inclined orbits.

June 1974 Rockwell International is chosen as the satellitecontractor for GPS.

July 14, 1974 The very first NAVSTAR satellite is launched.Designated as Navigation Technology Satellite (NTS)number 1, it is basically a refurbished Timationsatellite built by the NRL. The second (and last) of theNTS series was launched in 1977. These satelliteswere used for concept validation purposes and carriedthe first atomic clocks ever launched into space.

1977 Testing of user equipment is carried out at Yuma,Arizona.

February 22, 1978 The first Block I satellite is launched. A total of 11Block I satellites were launched between 1978 and1985 on the Atlas-Centaur. Built by RockwellInternational as developmental prototypes, the Blockystem testing purposes. One satellitewas lost as a result of a launch failure.

April 26, 1980 The first GPS satellite to carry Integrated OperationalNuclear Detonation Detection System (IONDS)sensors is launched.

1982 A decision to reduce the GPS satellite constellationfrom 24 to 18 satellites is approved by DoD following amajor program restructure brought on by a 1979decision by the Office of the Secretary of Defense tocut $500 million (approximately 30 percent) from thebudget over the period FY81–FY86.

July 14, 1983 The first GPS satellite to carry the newer NuclearDetonation Detection System (NDS) is launched.

September 16, 1983 Following the Soviet downing of Korean Air flight 007,President Reagan offers to make GPS available for useby civilian aircraft, free of charge, when the systembecomes operational. This marks the beginning of thespread of GPS technology from military to civilianaircraft.

April 1985 The first major user equipment contract is awarded bythe JPO. The contract includes research and

development as well as production options for 1-, 2-,and 5-channel GPS airborne, shipboard, andmanpack (portable) receivers.

1987 DoD formally requests that the Department ofTransportation (DoT) assume responsibility forestablishing and providing an office that will respondto civil user needs for GPS information, data, andassistance. In February 1989, the Coast Guardassumes responsibility as the lead agency for the CivilGPS Service.

1984 Surveying becomes the first commercial GPS marketto take off. To compensate for the limited number ofsatellites available to them early in the constellation’sdevelopment, surveyors turned to a number of GPSaccuracy enhancement techniques includingdifferential GPS and carrier phase tracking.

March 1988 The Secretary of the Air Force announces theexpansion of the GPS constellation to 21 satellites plus3 operational spares.

February 14, 1989 The first of 28 Block II satellites is launched from CapeCanaveral AFS, Florida, on a Delta II booster. The Space Shuttle had been the planned launch vehicle forthe Block II satellites built by Rockwell. Following the1986 Challenger disaster, the JPO reconsidered andhas since used the Delta II as the GPS launch vehicle.Selective availability (SA) and anti-spoofing (AS)or the first time with the Block II design.

June 21, 1989 Martin Marietta (after buying out the General ElectricAstro Space division in 1992) is awarded a contract tobuild 20 additional “replenishment” satellites (BlockIIR). The first Block IIR satellite will be ready forlaunch as needed at the end of 1996.

1990 Trimble Navigation, the world leader in commercialsales of GPS receivers, founded in 1978, completes itsinitial public stock offering.

March 25, 1990 DoD, in accordance with the Federal RadionavigationPlan, activates SA—the purposeful degradation in GPSnavigation accuracy—for the first time.

August 1990 SA is deactivated during the Persian Gulf War. Factorsthat contributed to the decision to turn SA off includethe limited three-dimensional coverage provided bythe NAVSTAR constellation in orbit at that time andthe small number of Precision (P)-code receivers inthe DoD inventory at the time. DoD purchasedthousands of civilian GPS receivers shortly thereafter

to be used by the Allied forces during the war.

1990–1991 GPS is used for the first time under combat conditionsduring the Persian Gulf War by Allied forces. The useof GPS for Operation Desert Storm proves to be thefirst successful tactical use of a space-basedtechnology within an operational setting.

August 29, 1991 The U.S. government revises export regulations,making a clear delineation between military and civilGPS receivers. Under the revised regulations, militaryreceivers continue to be treated as “munitions” withstrict export restrictions, while civilian receivers aredesignated “general destination items” available forexport without restrictions.

July 1, 1991 SA is reactivated after the Persian Gulf War.

September 5, 1991 The United States offers to make GPS standardpositioning service (SPS) available beginning in 1993to the international community on a continuous,worldwide basis with no direct user charges for aminimum of ten years. The offer was announced atthe Tenth Air Navigation Conference of theInternational Civil Aviation Organization (ICAO).

September 1992 The United States extends the 1991 offer at the 29thICAO Assembly by offering SPS to the world for theforeseeable future and, subject to the availability offunds, to provide a minimum of six years advancenotice of termination of GPS operations orelimination of the SPS.

December 8, 1993 The Secretary of Defense formally declares InitialOperational Capability of GPS, signifying that with 24satellites in orbit, GPS is no longer a developmentalsystem and is capable of sustaining the 100-meteraccuracy and continuous worldwide availabilitypromised SPS users.

February 17, 1994 FAA Administrator David Hinson announces GPS asthe first navigation system approved for use as astand-alone navigation aid for all phases of flightthrough nonprecision approach.

June 2, 1994 FAA Administrator David Hinson announcestermination of the development of the MicrowaveLanding Systems (MLS) for Category II and IIIlandings.

November 1994 Orbital Sciences Corp., a leading maker of rockets andsatellites, agrees to purchase Magellan Corp., aCalifornia-based manufacturer of hand-held GPS receivers,

in a stock swap worth as much as $60 million,bringing Orbital closer to its goal of becoming asatellite-based two-way communications company.

June 8, 1994 FAA Administrator David Hinson announcesimplementation of the Wide-Area AugmentationSystem (WAAS) for the improvement of GPS integrityand availability for civil users in all phases of flight.Projected cost of program is $400–500 million; it isscheduled to be implemented by 1997.

October 11, 1994 The Department of Transportation Positioning/Navigation Executive Committee is created to providea cross-agency forum for making GPS policy.

October 14, 1994 FAA Administrator David Hinson reiterates the UnitedStates’ offer to make GPS-SPS available for theforeseeable future, on a continuous, worldwide basisand free of direct user fees in a letter to ICAO.

March 16, 1995 President Bill Clinton reaffirms the United States’commitment to provide GPS signals to theinternational civilian community of users in a letter to ICAO.

GPS Satellites in Orbit. GPS Receiver

Importance of Land Surveying to Valuers

Land surveying or geomatics is recognised as being the second oldest profession in the world and is an umbrella term for the industry involved in the accurate & precise measurement of both manmade and natural features on the earth’s surface. Land surveying is also concerned with the analysis, collation, synthesis and presentation of this information for use in other industries such as environmental surveying, property development, solicitors and geologists to name a few. There is a rich heritage in the profession and has been at the core of developing the human environment since records first started being formalised. Historians have uncovered artefacts and records of evidence that ancient Egyptians used to measure and record the sizes and locations of building on the Earth’s Surface. 

No matter the scale of development it is important to obtain accurate and comprehensive data about the physical attributes of your proposed site. This is achieved through having a land survey carried out which will arm you with information about current and past ground conditions. For major projects like the recent boom that we have enjoyed here in Jamaica from the construction industry, land surveys help to mitigate risk throughout the development from the conceptualization phase right through to completion and is therefore an important component of any successful project or for just plain old knowing sake. A land survey will reduce risk and allow you to deliver a project on time and in budget by telling you the surface area, topography, boundary details, buildings and structure heights etc as well as ensure that works to be carried out are positioned correctly on site and can range from an intensely detailed map of an area, including measurements and positioning of all property, to simply a skeletal plan with only the key features.

A land surveyor is needed whenever a land survey is carried out. The most common reason for employing the services of a qualified land surveyor is when purchasing an area of land or property. The land surveyor will plot the position of the boundaries of the property in relation to the neighbouring boundaries in an effort to ensure boundary accuracy and minimize the risk of future boundary disputes. A land surveyor will also provide information in the land survey relating to ownership, rights of way and changes that have been made to the property which are not reflected in the house deeds. When boundary disputes to occur the services of a land surveyor are often employed in the capacity as an expert witness to provide the detailed information required to hopefully resolve an issue before it is taken to court where costs will quickly escalate.

The quantity surveyor is responsible for managing the finances and costs relating to a building project. This includes the full process right from the preliminary calculations through to final figures. It is the quantity surveyors job to keep the costs in check and to a minimum while still attaining high standards in terms of quality and service delivery. As a quantity surveyor it is important to have an in depth understanding of statutory building regulations. 

Building surveyors provide professional advice and guidance on matters relating to construction of property. They are particularly involved with the management, after care and performance of buildings. One of the major changes at the current time is the need for more sustainable buildings in order to reduce carbon emissions and negate the effects of global warming. Building surveying covers a vast array of roles such as building design, building maintenance, building refurbishment, building restoration and building dilapidations. 

Mining and quarrying needs specialist surveyors called mineral surveyors who understand the economics, mining law and relevant legislation. Mineral surveyors give valuation services to land from which minerals and aggregates are extracted such an mines, gas installations, onshore oil, quarries, methane extraction etc. 

Conclusion

The mere fact that a Valuer has to pull from records previously used by other Valuers depicts the necessity of knowing boundaries and all other relevant data that is associated with his subject property or comparables that can or will aid his decision making process. The Valuer relies heavily on the data collected by a surveyor to arrive at a value that is consistent with the property market. It also shows that before any form of value can be achieved there has to be some demarcation of what that property actually consists of; the surveyor is then the link between knowing what to value, how to value and what to value the property for. A valuation report is a prime example of how important the surveyor is to the overall process. The valuation report usually has a disclaimer stating that the actual boundaries and encumbrances that may be present. This is alluding to the fact that the valuation is not complete without the services of a Chartered Land Surveyor.

References

http://www.ccsni.com/surveying/track_record4.htm

http://www.rand.org/pubs/monograph_reports/MR614/MR614.appb.pdf