Reading the raw receiver data and generating RTCM messages is pretty straightforward. If you have suggestions for setting up a Kalman filter for generating the correction data, that would be very helpful - my linear algebra is not strong. Better yet, if you know of any code for generating the corrections, even if in Matlab, I could package it into a GPL package for a base station.
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Tomoji Takasu Sent: Saturday, November 13, 2010 6:44 AM To: Open Source GPS-related discussion and support Subject: Re: [FOSS-GPS] RTKLIB: How to use it to develop a cheap DGPS basestation? Dear Mauro > I was trying to follow your code, looking for the step where the > PseudoRange Correction and the Rate Range Correction (PRC[m] + > RRC[m/s]) are generated for each satellite (based on the raw data from > the device used as base and the fixed position of it) before being > feed to the solution computation for the rover position (when using > DGPS mode), but I couldn't find it. Current version (2.4.0) does not include RTCM output for DGPS or RTK base station. Please use receiver raw proprietary messages for this purpose at this moment. I will add RTCM output function in the future version for raw pseudorange and carrier-phase. I have not decided whether to support RTCM 2 PRC-type DGPS correction for many existing receivers. If many requests, I will consider it. regards, ******** Tomoji TAKASU WWW: http://gpspp.sakura.ne.jp -------------------------------------------------- From: "Mauro Ugarte Avilés" <[email protected]> Sent: Friday, November 12, 2010 5:17 AM To: <[email protected]> Subject: [FOSS-GPS] RTKLIB: How to use it to develop a cheap DGPS basestation? > Dear Tomoji, > > DGPS base stations are much more expensive than some well known > receivers that can output raw data, and considering that RTKLIB can > use that data and correct the pseudoranges of a rover, I was thinking > if it is possible to use those corrections to output them as RTCM > SC-104 messages, thus developing a cheap DGPS base station using, for > example, some decent antenna, an u-blox 5T and RTKLIB with some addition. > > I was trying to follow your code, looking for the step where the > PseudoRange Correction and the Rate Range Correction (PRC[m] + > RRC[m/s]) are generated for each satellite (based on the raw data from > the device used as base and the fixed position of it) before being > feed to the solution computation for the rover position (when using > DGPS mode), but I couldn't find it. > > Can you please give me some advice at where to look on RTKLIB code for > that computation step? Any other suggestion, tip or comment about what > I'm trying to do will be more than welcome. > > Best regards to you and all list members, > > Mauro Ugarte A. > > PS.: For those of you wondering why do I want to use DGPS in the first > place, is because here in Chile there is nothing like WAAS, and I need > to increase accuracy on pedestrian rovers on rural areas, where the > ammount and quality of the data required for RTK are unachievable with > small GPS antennas and variable RF links. > -- > Este correo electrónico y cualquier archivo adjunto son > confidenciales y son solamente para el uso del individuo o entidad a > la que van dirigidos. > Si ha recibido este correo electrónico por error por favor > notifique al remitente. Este mensaje contiene información > confidencial dirigida a la persona implicada. Si usted no es esa > persona no debiera diseminar, distribuir o copiar este mensaje de > correo electrónico. > _______________________________________________ > This message is sent to you from [email protected] mailing list. > Visit http://lists.osgeo.org/mailman/listinfo/foss-gps to manage your > subscription For more information, check > http://wiki.osgeo.org/wiki/FOSS-GPS > > > _______________________________________________ This message is sent to you from [email protected] mailing list. Visit http://lists.osgeo.org/mailman/listinfo/foss-gps to manage your subscription For more information, check http://wiki.osgeo.org/wiki/FOSS-GPS _______________________________________________ This message is sent to you from [email protected] mailing list. Visit http://lists.osgeo.org/mailman/listinfo/foss-gps to manage your subscription For more information, check http://wiki.osgeo.org/wiki/FOSS-GPS
