Non-real-time base/rover processing?
If I have two receivers and want to use them in a base/rover fashion with no radio link, is there any free service or software for post processing vectors?
My idea is to write a program to filter the RINEX files to contain only the satellites at each epoch that both receivers recorded (see other thread about manipulating RINEX). Then submit minimum-length OPUS-RS runs and take the difference of the resulting positions as the vector. Add the vector to the long session at the base to get rover position.
This should give a more accurate vector than comparing results from everything the receivers captured, assuming they have enough in common. The proprietary software must do something similar.
What sort of vector accuracy would you expect from this procedure under open sky?
I don't know of any OPUS processing that would connect with the rover if we are discussing short session times, but it will with the base, from there you control the rover locations, or use CORS data to process the base and the rover; sub cm for the locations. Basically you are wanting to do static on the rover from the base or from CORS data, you can then adjust the vectors to the rover antenna, if you wish to have multiple vector solutions. As always way more important to get multiple sessions on any point.
It's done all the time in my Trimble software which is far from free, maybe a demo version of one of the vendor's software will do that.
I have software I have purchased or it came with receivers I purchased that has always done that. It was not expensive so I never took the costly time to look for something free. Pretty much you leave all the data in there, common or not and let the software use what it considers best. Because of the many short files in the rover receiver sometimes one or more satellites does not get properly resolved. On occasion you may have to remove it but I have found out afterwards that that bad data was already being ignored. My software informs me of the number of common satellites used and the PDOP. It is easy to see if you actually had to get involved.
If you own certain receivers the original agreement included the right to use specific software which may be out there to find. Other manufacturers required you to pay for everything and every upgrade.
Whether or not you have a base and a rover, your best bet is to find software that can create a VirtualReferenceStation. A created VRS base point file is free of any obstructed satellites that may have occured with an actual receiver in the field.
Paul in PA
Paul, your software was probably not expensive in the context of a professional business, but I don't make any money for playing with this stuff.
If you're content to process only L1 signals, I think you can get a free copy of Ashtech Solutions. Probably could get a few others, too, if you're content with L1 only.