Relative RTK

FSL Relative GPS Development Kit

Relative GPS also known as “Moving Base” operations requires high levels of position, heading and attitude accuracy in real-time. Often centimetre level precision is required. These accuracies can be obtained from RTKNav, RtEngine and RtDLL RTK processing programs. All three compute accurate position, velocity and attitude in a PC environment. The three packages, RTKNav, RtEngine and RtDLL, have feature combinations not necessarily available in embedded GPS receiver RTK firmware. Such features include: multi-remote processing, moving baseline processing, azimuth determination, 3D attitude determination, single and dual frequency on-the-fly positioning and flexible control over data logging and processing modes.

RTKNav is a Windows based program complete with an operator GUI while RtEngine is the same software with a command line user interface and all serial port control included. Users of RtEngine will normally develop their own GUI to give a personal touch. Both software packages include RtDLL which is simply a high speed computation DLL. Stripped of all non-essential software functionality RtDLL allows development programmers a fast start to their end-product where high speed data processing is a requirement.

For many marine applications, including seismic and ocean research, the relative distance between ships and buoys are often required. This is where RTKNav/RtDLL are both well suited. RtkNav/RtDLL’s carrier phase processing mean that accuracies attained are much higher than code-only processing techniques.

RTKNav and its derivatives can also be used for 2D heading and 3D attitude determination.

An inexpensive Relative GPS (RGPS) system can use existing non-RTK GPS receivers with raw pseudorange and carrier phase output. Alternatively a low budget system would utilise two or more Smart Antenna receivers as the mobile units. High performance from NovAtel receivers would be achieved using OEM4-G2 or G2L L1/L2 receivers.