OPUS Alternatives GPS World Article by Mark Silver

Good article thanks

Very good Shawn. Also note that all of these other services, with the exception of the Canadian PPP, will be using only those CORS that are part of the IGS network (International GNSS System Service) and depending on where you are they may be several hundred miles away and not at all related to the NGS CORS network. That being said in most cases where I've compared results from AUSPOS to OPUS (once I've transformed the AUSPOS ITRF values to NAD 83 using HTDP which of course is currently blocked) I usually find differences of just a few cm.

If you have Topcon Tools or Magnet Tools you can use the "Import from Internet" option to still download static data from CORS.

It worked yesterday, and just tried again, and still works.

If you are in Florida ...

The FDOT's website (myfloridagps.com) has an OPUS like feature called "Computation Service". On the upside, it worked last time I tried it. On the down side, it doesn't produce a lot of stats to give you the warm fuzzies about your results. If you are in a bind now, and in or near Florida (some LA, AL, and GA stations can be used), it may be helpful.

One important thing to remember is that most of the alternative sites won't process a 15-minute file.

Also, I don't know for sure that data will continue to be collected. At some point, some CORS stations, may have missing data which will tank any OPUS-RS solutions in the vicinity. (I read the shutdown order and I think a guy could get fired for doing the right thing.)

Just to be safe, grab 1-hour occupations until the shutdown settles out. That way you can dependably process in RTX or AUSPOS.

What a mess. But, I won't go there.

Mark

> One important thing to remember is that most of the alternative sites won't process a 15-minute file.
>
> Also, I don't know for sure that data will continue to be collected. At some point, some CORS stations, may have missing data which will tank any OPUS-RS solutions in the vicinity. (I read the shutdown order and I think a guy could get fired for doing the right thing.)
>
> Just to be safe, grab 1-hour occupations until the shutdown settles out. That way you can dependably process in RTX or AUSPOS.
>
> What a mess. But, I won't go there.
>
> Mark

Nice article Mark. Thanks for the help.

Larry P