I submitted a file a while back that was collected on Nov 2, and got back a report using rapid orbit data:
EPHEMERIS: igr18691.eph [rapid]
I re-submitted it last night and it says
EPHEMERIS: igs18691.eph [precise]
but the positions, pk-pk, rms, etc. are the same to the last digit. There are some very minor differences in the vectors but they don't change the new point by a millimeter. Does this actually occur, or is there a glitch somewhere?
In my experience, which is kinda limited lately, it occurs all the time.
The rapid orbit seems to be pretty good most of the time.
I have seen differences between the precise and the ultra-rapid orbits. That's why I'd wait at least a day before sending up my observations.
The rapid orbit has gotten better over the years as the speed in which data getting to the orbit computer increases.. The only reason to wait for precise orbit is if it is a contract issue.
As the rapid orbit has improved so has the ultra-rapid orbit and I have several times used the ultra-rapid orbit and seen less than 0.001m changes to the rapid. Using OPUS-RS, especially with vectors to 9 CORS, the results change very little.
Paul in PA
Here's my 2-bits worth...
Ultra-Rapid v Rapid = non-trivial (IMO) variances SOMETIMES...maybe often in some cases.
Rapid v Precise = non-trivial (IMO) variances RARELY (if ever).
Vector Length factors into the above 2-bits more than observation duration does (usually).
The average "CONTROL POINT" in my work has AT LEAST 2 (usually 4 or more) 4-12 hour observations, usually spanning AT LEAST several days (sometimes months or even years).
Individual CORS behavior (N/E/U), both Short-Term and Long-Term, SHOULD be watched closely if you want good (repeatable) OPUS Solutions. CORS showing discontinuities due to equipment (or firmware) changes, or crustal movement, should be avoided if possible...okay...I'm drifting off the subject AGAIN!
Loyal