GIS Guy in Alaska – Not doing Boundary Work

[jimcox]

When mixing, we usually use the R10 as the base.

This is because our R10s have a 2W radio, vs the 0.5W in the R8 so we get better range

 

[lee-d]

When mixing we use the R8 as the base. You’re going to get better results with an R10 than with an R8 in any application, from my experience, and I’d rather have that better performance at the rover. Plus the R10 has XFill and the tilt sensors, which are of no benefit at the base. As far as a GPS only OPUS solution on a 4 hour+ session is concerned, you might see better numbers with an R10, but I’d be surprised if the difference in the position was more than a few millimeters.

[john-putnam]

Running multi constellation receivers locally is not wasted.  While only GPS will be used to solve the base’s position by OPUS, all available GNSS signals will be used in your RTK or post processed solutions between your receivers.

[MightyMoe]

Jim is right that the R10’s radio is better at the base, Lee is right that the R10 is a better rover.

If you are going to set up a repeater anyway then use the R8 at the base for sure, if you need a bit more power at the base and you think the R10 will make a difference to save setting up a repeater then do that. 

As far as the CORS being GPS only, you aren’t using it for anything other than post processing the base, so it doesn’t matter.

But since you have R8’s and R10’s I would say you aren’t using them to their full potential not connecting to CORS data more. You don’t need to set for four hours, you don’t have to send it to OPUS and you don’t have to have a base set up to get good data with an R10 or R8 and CORS. It depends on what your task is. 

CORS creates a file for any time frame, if you sit on a point for 2 minutes you can process it to a nearby CORS. The rover data can treat CORS data as if it were your base, so using it for PPK or fast static is no problem. 

[gisjoel]

Thanks everyone.  As with any question I pose with this group, I learn so much.

Thanks John – I get it now that the GNSS is not wasted in my situation with single base.  That’s a very good point.

I use XFill sometimes so I lean on using the R10 for that reason, and like Mighty Moe mentions, we use our TDL 450’s quite a bit since our range between base / rover are always “on the fringe” of reception and I can’t risk leaving my base without the extra boost that the external radio provides.

Unless I hear different, I’ll continue to keep things simple and design our kits with the R8 Base / R10 Rover.

As a long-time Post Processor Mapper, we use short occupation all the time with our GeoExplorer’s and pull amazing 5cm-10cm accuracies when I can confirm them against control, nearby. Thats my issue – I’m in the middle of nowhere, no control that I can trust, so PPK/Fast Static feels to risky for me with out the experience and education that Mighty Moe brings to the field.  Risky, because I have not built up my confidence like Mighty Moe.  I also have tried to build out our OPUS Shares up here, hence the 4 hour minimum I’m forcing on our ologists.  Remember, were ologists who can screw up a coordinate if the wind blows out of the West, so that OPUS solution printed out, or sent to the controller is GOD when we are lucky to return to a site.  

Thanks all.

[lee-d]

To you have TBC? I rarely send single bases to OPUS (I do send networks to OPUS Projects).

[MightyMoe]

With an R10 I would do some testing,,,,,,try some PPK and fast static at the office parking lot, maybe on a point that is already controlled and some continuous topo shots. You may be surprised how accurate it can be to CORS. Of course, if the nearest CORS is 100 miles away it won’t work very well, but if it’s within 20-30 miles it should. It isn’t very difficult. 

I’m assuming you have TBC

[Williwaw]

Just an aside, if you’re having trouble with not having a CORS close enough, there are quite a few GPS stations scattered around the state used for monitoring plate tectonics and I have used their data in the past for post processing with quite good success. It’s been a while since I’ve used any of it but it is out there and available. One of these stations saved my bacon years ago as I think the closest working CORS was like 300 miles away, but I was able to find data from a UAF monitoring station within ten miles of the project I was working on. I was using resource grade Trimble gear and was able to get my data from 1-2 meter accuracy, down to a couple of decimeters using the UAF data for postprocessing. Some times got to think outside the box. ???? 

https://www.nps.gov/articles/dena-factsheet-pbo.htm

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Willy

[gisjoel]

Mighty Moe – Will do.  With help from our local Trimble dealer we have leveled in with a DINI Level (I think that is what it was called) and ran the network of 5 CP’s with OPUS projects.  So my testing ground is good (at least prior to our 7.2 Earthquake on November 30 of this year.

I do all the processing with TBC John.  For our single base RTK, typically using a HERE command I run the T01 file through Rinex and submit to OPUS for our final solution.  I have used OPUS projects using one point (without the benefit of simultaneous bases running) under guidance from our NGS advisor at points I want to be tighter, but my gut says the OPUS I’m getting is good enough for our work in remote areas of the state.

Thanks Williwaw, I have found the PBO sites (NON CORS) to be valuable  as well.  I do wish we had a one-stop app that mashed up all the possible sites, but that is something in the future I suppose. 

Joel

[lee-d]

Have you tried the Internet Download command in TBC? It wouldn’t surprise me a bit if they have links to all of those stations.