Just wanted to share something really cool. An alternative to OPUS processing. Have you ever uploaded a file to OPUS and had it rejected? LOL. Well this trimble process includes GLONASS also. Opus doesnt use glonass when processing. Thus opus only takes advantage of half of the available satellites. In other words points that wouldnt fix with OPUS have a very good chance of fixing with the Trimble site. It is called Trimble CenterPoint processing. It is 100% free. One thing to note is you have to register before uploading files or they wont email you the results. The url is...
http://www.trimblertx.com/UploadForm.aspx
I just wanted to share it with everyone because it has saved the day a time or two for me. Enloy! 🙂
I love it so far. Has anyone else on here used it?
I use it often. Great tool. I have found that 30-45 minutes can be iffy, above 45 minutes is almost always OK. 60 minutes or more has always worked for me at the cm level.
It is not dependent on local CORS, although it does use a network of worldwide CORS to compute corrections, it does not bomb out the way OPUS-RS does if the nearby CORS are missing
They also offer a real time version (over sat link) for a subscription. If you have the right receiver (R10), it works great, solves in under 30 minutes anywhere in the world.
I agree. I've not tested to see if it is any more accurate, but it definitely seems to be more precise. In other words: values returned from Trimble's service seem to usually match total station observations better than OPUS (obviously if the scale factor is applied).
Thanks for sharing. Sounds like another great blunder detection tool, and another processing check.
What Does A Report Look Like ?
How many reference stations does it use?
Does it identify the reference stations?
Does it use only Trimble reference stations?
Does it provide an idea of how precise the solution is?
Paul in PA
What Does A Report Look Like ?
It creates a nice looking pdf report. Just submit a file to Opus and Trimble and compare. After all its free and only takes 1 minute. I like trimble report better. I think you will be pleasantly surprised with the comparisons.
Sure could have used that during the government shutdown a couple of years ago.
Lovely idea as long as you are not going to sign and stamp a Flood Elevation Certificate. OPUS was originally intended to only be used as a "check." It has been misused ever since, but now apparently FEMA accepts the results as gospel.
If something happens to the insured property and if you did NOT use OPUS ... betcha you're gonna be between a rock and a hard place.
What Does A Report Look Like ?
It is basically a PPP service (precise point positioning), although it does use a network of stations to compute the corrections. As I understand it, it is not directly using data from reference stations (i.e. processing or solving for vectors). It uses the reference stations to solve for the various parameters like orbits, clocks, ionosphere, etc.
Here is a white paper on the RTX service:
You can automatically send data files from TBC, but they must be a minimum length (I can't remember, maybe 60 minutes). If you use the web interface, you need to type in one of those stupid captcha's each time, which is a PITA. But the results are returned in a matter of minutes, usually less than a minute (last time I used it).
One comment...it has a limited number of antennas available. Of course, you could use unknown external, but you will probably be affecting the results as it cannot model the offsets.
Right now I am running an X90D OPUS receiver on my pedestal. This model is in the OPUS list of antennas, and is now in the TBC list (3.40), although it was not previously in TBC, last time I looked which was probably 3.30(?). RTX does have an option for CHCX900R, so hopefully they will add the X90D OPUS in the future.
Also, I have found that the RTX processor works much better (i.e. solves the integer ambiguities faster) with multiple constellations. I did some testing with an R10, and did 20 sessions of 29 minutes each (GPS and glonass). The rms in X was 0.006 m, in Y 0.020 m, and in Z 0.016 m (ECEF, not local horizon).
RTX is pretty cool. They used to require a Trimble engine, however they have opened RTX up to other receivers. However as mentioned above, the antenna list is not complete.
The other issue may be the lack of an orthometric height and state plane coordinate in the output. You can solve this with INTG and SPCS83.
You can also use AusPos (which I kind of like even better because it has a full antenna list), but in addition to not providing ortho elevations and State Plane coordinates, it also does not have NAD83 framed results.
By chance I wrote an article for American Surveyor on exact subject and it is in the current issue: Geodetic Preppers
what are the chances of that!?
Take care!
M
