The latest GPS receiver to be fully integrated in to the Inertial+ navigation system is Topcon’s GB-500. By combining the GB-500 receiver with an Inertial+ system you can remove jumps from the position measurements, increase the output data rate and include orientation measurements with your data.
The GB-500 uses a Topcon dual-frequency, dual-constellation (GPS and GLONASS) receiver board. It is housed inside a rugged, compact housing featuring a simple MINTER display with LEDs providing satellite tracking, battery, and recording status. At its core is the Paradigm chip featuring 40 universal channels capable of tracking L1 and L2 frequencies for both GPS and GLONASS satellite systems. It incorporates the new innovations in signal processing, multipath mitigation and co-op tracking.
The Inertial+ receives data from the GB-500 using the GRIL binary output format, which maximises the performance of the Inertial+. OxTS has tuned the compact inertial navigation system so that it is perfectly optimised for use with the GB-500 receiver. The Inertial+ can output its measurements in NMEA format, making it compatible with most user applications. Other output formats are available.
“Even though the GB-500 is good at tracking under tree canopies, the Inertial+still improves the position measurements of the GB-500 in these difficult conditions,” explains Brendan Watts, Marketing Director at OxTS. “For vehicle applications where tree cover leads to annoying jumps in the GNSS position the Inertial+ is ideal.”
Using the GB-500 with other Topcon equipment, such as radios or cell-phones, can give differential corrections while on the move. This keeps the differential corrections separate from the Inertial+ and allows OxTS to use the best data while focusing on the difficult task of improving the position.
The GB-500 was tested using the standard positioning service (SPS), using differential corrections (DGPS) and using RTK corrections. The performance in all three modes was good, as is expected from a survey grade GPS receiver of this quality.