Trimble announced that the company's R-Track technology was used to verify the interoperability of the new Block IIR-M Global Positioning System (GPS) satellite payload with current and modernized survey equipment. The Trimble R7 RTK GPS system is the only L2C-ready survey equipment currently available to test the new satellite signal by the Joint Program Office (JPO), which manages the Navstar GPS system. The Trimble R7 system, which can take advantage of today's GPS satellite and future L2C signal, successfully showed that the Block IIR-M satellite's data can be acquired, tracked and logged.
The announcement was made at the American Congress of Surveying and Mapping/Tennessee Association of Professional Surveyors (ACSM/TAPS) Conference and Technology Exhibition.
The Block IIR-M GPS satellites are part of the Department of Defense's (DOD) GPS Modernization Program. GPS Modernization will add two new signals and increased signal power for civilian users over several years--as well as advanced features and new signals for military use. Built earlier, the IIR-M satellites have been "modernized' with the new civilian L2C code as well as two new military codes; the DOD plans to modernize up to 12 Block IIR satellites currently in storage.
The test took place at ITT Industries in New Jersey where the Block IIR-M satellites are being tested before launch. The first Block IIR-M satellite, scheduled for launch within the next 12 months, will send a new civil GPS code on the L2 signal, referred to as the L2C signal. L2C-ready civilian GPS receivers will be able to track the new signal code directly, yielding improved reception compared with previous indirect reception techniques.
Various tests were run with the Trimble R7 survey system. JPO used a commercial simulator to imitate the GPS constellation and generate current signals. The simulated constellation was then coupled with the output from a IIR-M satellite; this made it possible to track and use the current signals together with a Block IIR-M satellite and produce a solution.
Source: Trimble, April 19, 2004