5 ms·
It's not possible, even with pretty ideal conditions. Edit: I excluded RTK stuff in that comment :)
by chrissmithuk 13y ago
It's not possible, even with pretty ideal conditions.
Edit: I excluded RTK stuff in that comment :)
- stefantalpalaru 13y agoIt is, using RTK (real time kinematic) and 2 different receivers: http://www.kickstarter.com/projects/swiftnav/piksi-the-rtk-gps-receiver http://www.kickstarter.com/projects/swiftnav/piksi-the-rtk-g...
- Nrsolis 13y agoAnd there you have it. This is from the datasheet of the Trimble R10 surveying receiver: real time Kinematic surveying Single Baseline <30 km Horizontal ...................................... 8 mm + 1 ppm RMS Vertical ....................................... 15 mm + 1 ppm RMS Network RTK3 Horizontal ..................................... 8 mm + 0.5 ppm RMS Vertical ...................................... 15 mm + 0.5 ppm RMS RTK start-up time for specified precisions4 .....................2 to 8 seconds Trimble CenterPoint RTX Horizontal .................................................. 4 cm Vertical .................................................... 9 cm RTX convergence time for specified precisions12 ........... 30 minutes or less RTX QuickStart convergence time for specified precisions12 .... 5 minutes or less Trimble xFill5 Horizontal ................................. RTK6 + 10 mm/minute RMS Vertical ................................... RTK6 + 20 mm/minute RMS
- chrissmithuk 13y agoYes but that somewhat limits the practicality because you need two receivers, a clear signal path between them and one has to be relatively static. It's fine for surveying but for dynamic applications which are far more common, it's a pain.
- Nrsolis 13y agoThen you engineer another source of correction and incorporate that into your project. The US Navy has been doing accurate position determination using ZERO satellite availability. How do you think a submarine knows where it is? http://www.liveleak.com/view?i=aba_1332656862 http://www.liveleak.com/view?i=aba_1332656862
- toomuchtodo 13y agoYou can receive RTK corrections over IP (via a cellular connection). Government bodies across the US push the data over IP to you if you register for a free account. http://igs.bkg.bund.de/ntrip/index http://igs.bkg.bund.de/ntrip/index http://en.wikipedia.org/wiki/Networked_Transport_of_RTCM_via_I http://en.wikipedia.org/wiki/Networked_Transport_of_RTCM_via... nternet_Protocol
- randomdata 13y agoIn agriculture, it is not uncommon to get correction data over mobile data connections, where the static receiver is provided by a third-party service provider.
- Nrsolis 13y agoWelll.....that's not strictly true. If you've got an environment free of multipath, you use differential or WAAS-enabled GPS receivers, you can get pretty good accuracy. Source: http://www.oc.nps.edu/oc2902w/gps/gpsacc.html http://www.oc.nps.edu/oc2902w/gps/gpsacc.html Please note that all of these things depend on many factors and can be considered nearly "heroic" measures when it comes to position accuracy, but the Navy has historically been pretty damn concerned about knowing where their assets are and is somewhat obsessive about error-factors where that's concerned.
- MrUnderhill 13y agoWith orbit and clock corrections delivered to the receiver in ~real time (such as Fugro's G2), you'll get <10cm (95%) on a standalone receiver.
- Nrsolis 13y agotranslation: I didn't know about RTK before I posted. Thanks for schooling me.