Land survey GPS and P2V?

[GetaGrip]

Anyone out there in P2V land that has experience with Survey GPS? My plans are to be covering construction of a large Hydroelectric project over the next 7 years. On a previous project I was introduced to a fairly new technology that utilized a number of GPS ground stations placed around the site on land based benchmarks that were described to me as GPS repeaters. They were mounted on a heavy duty tripod and self powered with battery/solar.

My question is, could these effect or possibly jam the P2V GPS system and cause a fly away.

 

[dkatz42]

The term "GPS repeater" is a misnomer. The ground stations compare their known locations to what GPS is indicating and then broadcast correction data so that the survey receiver can be more accurate. They almost certainly transmit in the VHF band, and certainly do not transmit in the GPS band, since they would overwhelm everything (including their own reception). The signal levels at GPS receivers are astonishingly low.

 

[stenno]

Survey GPS works on system called differential GPS, where two GPS receivers are used, to gain a more accurate result in real time. One receiver is set as a base station on a known point. The difference of the calculated GPS point compared to the known point is sent to the rover receiver over a radio connection. In my experience as a surveyor if has been in the low UHF range however some devises send in VHF, depends on the brand of instrument that is being used.


The radio system has no effect on the GPS signal strength, and is transmitted intermittently every second, repeaters can be used to increase the usable range from a base station and are simply a standalone radio system repeating on the opposite second to the base.

 

[GetaGrip]

Great info, Thank You.