GPS Standard Formats Part 1

Since individual GPS manufacturers have their own proprietary formats for storing GPS measurements, it can be difficult to combine data from different receivers. A similar problem is encountered when interfacing various devices, including the GPS system. To overcome these limitations, a number of research groups have developed standard formats for various user needs. This topic […]

GPS Standard Formats Part 2

RTCM SC-104 standards for DGPS services Real-time DGPS operations require the estimation of the pseudorange corrections at the reference receiver, which is then transmitted to the rover receiver through a communication link. To ensure efficiency of operations, the pseudorange corrections are sent in an industry standard format known as the RTCM SC-104 [4]. This format […]

GPS Integration

GPS has found its way into many applications, mainly as a result of its accuracy, global availability, and cost-effectiveness. Unfortunately, however, there exist some situations in which part of the GPS signal may be obstructed to the extent that the GPS receiver may not "see" enough satellites for positioning. Examples of those situations are positioning […]

GPS Applications Part 1

GPS has been available for civil and military use for more than two decades. That period of time has witnessed the creation of numerous new GPS applications. Because it provides high-accuracy positioning in a cost-effective manner, GPS has found its way into many industrial applications, replacing conventional methods in most cases. For example, with GPS, […]

GPS Applications Part 2

GPS for land seismic surveying Oil and gas exploration requires mapping of the subsurface geology through seismic surveying. In land seismic surveys, low-frequency acoustic energy is sent down into the underground rock layers (Figure 10.7). The source of the acoustic energy is often selected to be a mechanical vibrator consisting of a metal plate mounted […]

Other Satellite Navigation Systems (GPS)

GLONASS satellite system GLONASS is an all-weather global navigation satellite system developed by Russia. The GLONASS satellite system has much in common with the GPS system. The nominal constellation of the GLONASS system consists of 21 operational satellites plus three spares at a nominal altitude of 19,100 km. Eight GLONASS satellites are arranged in each […]

GPS Accuracy and Precision Measures

The term accuracy is used to express the degree of closeness of a measurement, or the obtained solution, to the true value. The term precision, however, is used to describe the degree of closeness of repeated measurements of the same quantity to each other. In the absence of systematic errors, accuracy and precision would be […]

Useful Web Sites (GPS)

GPS/GLONASS/Galileo information and data Canadian Active Control System (CACS data and service): Geodetic Survey Division of Geomatics Canada: Galileo EC page: Galileo World magazine: GPS World magazine: International GPS Service for Geodynamics (RINEX and precise ephemeris data): International Terrestrial Reference Frame (ITRF): Ministry of Defence of the Russian […]

Table of Constants (GPS)

Symbol Value Unit Explanation cf. 6378137 m Semimajor axis of WGS-84 §2.1 1 / 298.2572236 Flattening factor of WGS-84 §2.1 6378136 m Semimajor axis of PZ-90 §2.1 1 / 298.2578393 Flattening factor of PZ-90 §2.1 6378136.54 m Semimajor axis of ITRF-96 §2.1 1/298.25645 Flattening factor of ITRF-96 §2.1 84381 ."412 Obliquity of the ecliptic at […]

Abbreviations and Constants (GPS)

Abbreviations AF Ambiguity Function AS Anti-Spoofing AU Astronomical Units BDT Barycentric Dynamic Time C/A Coarse Acquisition CAS Chinese Academy of Sciences CIO Conventional International Origin CHAMP Challenging Mini-satellite Payload CRF Conventional Reference Frame CTS Conventional Terrestrial System DD Double Difference DGK Deutsche Geodatische Kommission DGPS Differential GPS DOP Dilution of Precision ECEF Earth-Centred-Earth-Fixed (system) ECI […]