I have been using the post processed version of Trimble RTX and have been getting very good results with 45 minutes of data, a couple of cm. It is a PPP solution (Precise Point Positioning).
Is anyone using the Centerpoint RTX service? This is a real time solution that comes over a satellite link, and initializes in under 30 minutes. They do offer a 3 day demo, which I am using now. I have found that after about 10 minutes it is under 5 cm H/7.5 cm V accuracy, but sometimes it takes a bit longer. I sometimes have jobs in remote locations where 5 cm H and 10 cm V is acceptable. I have just done a few points and the times were right around 10 minutes to start observing when the precisions were set at 0.05 m/0.075 m. I am going to tighten the tolerances and see how long it takes.
I would be interested to hear from anyone who has used this subscription service as to how well it works under varying conditions. I am using an R10, and so far have been pretty wide open (i.e. no obstructions, no multipath) in my tests.
Of course, it gives coordinates on ITRF2008 2005.0, but that isn't a problem as they can be transformed to NAD83 (2011) either on the fly in the data collector or afterwards in the office.
I haven't used the subscription service but XFill on the R10s has been pretty darned handy on more than one occasion. It's absolutely seamless, which tells me that the R10 is always tracking the RTX satellite - you just pay the subscription to unlock it.
I believe that the R10 is the only survey receiver that can use RTX, unless they enabled it on the new R8s. But our GIS guys are evaluating an R1, and it can use it with their Terra Flex software. That R1 is a very cool device and is being marketed in a very un-Trimble like fashion - it's priced very competitively and can be used with just about any device. We're thinking about using it with an Android tablet.
We've been testing RTX post-processing on a few jobs lately and have been comparing the results to OPUS and AUSPOS. One of the big benefits we see is the speed of the service. Where the other online services take up to an hour to crunch a big file, RTX does it in minutes. The results are slightly different from OPUS, up to 5cm range on some sites, been after applying HTDP. I attribute this to application of different tectonic models.. but not sure really. I'm happy with RTX though but wish the reports contained more info, perhaps a graph of residuals.
