> What exactly is a "Rinex"?
Receiver INdependent EXchange format, a specification for GPS observation data. Most receiver manufacturers store data in a proprietary binary format usable only by the manufacturer's own software. RINEX was born as a means of allowing that data to be used by any software capable of reading the RINEX format, which is an open standard. The manufacturers -- all of which I'm aware, anyway -- cooperate by providing RINEX converters with their receivers.
The RINEX Specification details the file contents and format.
And if you nose into RINEX at all, you'll also want to know about TEQC.
Thanks, Jim. Your explanation of Rinex is far more understandable than Wiki's, but I didn't get much out of the two links.
Dave
> but I didn't get much out of the two links.
Save those for reference. For most projects you won't need to use either one, but with them you can sometimes salvage data that might otherwise be unusable.
Sorry, I am just now getting on the computer. Sometimes I have to wait a day until I can get a good solution. It depends on when the "local" CORS update/upload their data.
As to the specific issue of orbit availability, even the ultra-rapid orbits are adequate for most work.
For a tabulation of the relative accuracy of each orbit type, see: http://igscb.jpl.nasa.gov/components/prods.html
Orbit accuracy over distance to SV is proportional to baseline error over baseline length.
The table also provides latency for orbit products.
Availability of CORS data is another issue.
On the issue of baseline error as a function of baseline length, see the article by Eckl, et al available on the NGS site. http://www.ngs.noaa.gov/CORS/Articles/Time_v_Distance.pdf
There is a more rigorous version is available in the Journal of Geodesy (but it is not free).
Given its low cost and your recommendation, I only wish I had a spare $2K...
I can whole heartedly recommend the X90-OPUS receivers. I purchased my first one in December 2013, and my second one in May of 2014.
I get very good results with them. Mark Silver has been outstanding with his customer support.
"As far as differing from the Leice Viva... the list price on this receiver is currently $1880 including shipping to your door."
And support from Mark Silver!:good:
T.W.
