Collector + Trimble R2 cm level accuracy

[KaylaFlamm]

Does the Collector app support the centimeter level accuracy you can get with a Trimble R2? I have heard that it does not, that Collector currently only supports sub-meter accuracy such as with a Trimble R1. Can anyone confirm this or perhaps give an estimate on when such a functionality might be available if it isn't already?

Thanks!

[RuiGe]

Hi, Kayla,

Support for external GNSS receivers is included in our plan for future release. If you would like to participate in the Beta testing, please email Collector4ArcGIS@esri.com with information such as your name, organization and devices you want to use.

thanks,

Rui

[AndrewMilanes]

Trimble has a smartphone app called GNSS status that you use in conjunction with their R1 and R2 receivers.  When you connect to the R1/R2 receiver using that app, it overrides the internal GPS on your smartphone.  If you are using a real-time correction service such as a VRS network, you should get cm(ish) accuracy with whatever data collection app you use, including Collector.  I have an R2 but have not tested it with Collector yet, but I see no reason it wouldn't work.

However, you will only get this type of accuracy with a VRS connection since currently Collector does not support post-processing.  Also, this is for horizontal only as Collector does not have Geoid support yet either.

One more note, in order to get cm accuracy with the R2, you have to purchase one of the RTK variants of the receiver.

[JeffreyNormandin]

I inquired with a salesman about what equipment I could get that would allow high-accuracy data collection into Collector on an iPad.  He told me the R2.  We bought it and now I can see the high-level of accuracy in the Trimble GNSS Status app, but Collector isn't receiving any GPS signal from the R2 whatsoever - if you walk the iPad away from the R2, the position in collector follows the iPad.  So obviously the position isn't being passed along to other apps.

I went back to the salesman, but he had obviously never actually tried it, and he came back to me with the answer that it was because Collector can't communicate with the Trimble, but the Beta version that Rui Ge referenced above would solve all my problems.  Based on what I see in this discussion and elsewhere, I have a feeling my issue is all about setting the Trimble and iPad up properly to communicate, and that the Collector app alone isn't the reason for my total lack of communication between the two apps and pieces of hardware.

Can any of you confirm my suspicion, or offer guidance on how to resolve it?  I am definitely interested in getting the highest level of positional accuracy that I can, but first I just want to see that my settings are squared away so everything can communicate properly.

Thanks,

Jeff

[AndrewMilanes]

Jeff, I tested my R2 with Collector and it worked like I expected.  Here's what I did.

I setup my R2 outside my office on a bipod:

From inside my office I connected to my R2 via bluetooth using the GNSS Status app:

Then I opened Google Maps and Collector.  Both showed my location in the correct spot outside of my office:

The dot didn't move even if I walked around.  To ensure this was showing my location from the R2, I disconnected my bluetooth connection and my location changed:

One thing you may want to check is your NMEA output.  I don't think this has anything to do with iOS or Android apps, but it is used with ArcPad on Windows Mobile.

That's pretty much all there is to it.  If you follow these steps, I see no reason that it won't work.

[JadeFreeman]

Has anyone gotten this to work with the Trimble R10 receivers?

[AndrewMilanes]

I don't think the R10 is supported via the GNSS Status App, which is what you need in order to override the internal GPS on smartphones.

[JadeFreeman]

Thanks...just the information I was looking for!

[KaylaFlamm]

I have been able to get the Trimble R1 to work just fine with the Collector app on the iPad. The dot follows the R1 rather than the iPad, and it seems to have the accuracy that is displayed in the GNSS Status App. So all good there.

When we inquired about purchasing a Trimble R2 (thinking that it would work the same way as the R1 and would get the cm-level accuracy by using the free RTK network offered by the Dept of Transportation in MO), the sales rep claimed that it is not currently possible to have this cm-level accuracy stream to the Collector App. Needless to say... this confuses me. Why would it work fine with the R1 but not the R2?

And yes, I am aware that the Collector app doesn't support post-processing nor does it give you the information you can get from the GNSS Status app. That's not the thing that's tripping me up here.... its the fact that I've been told the Collector app won't support the cm-level accuracy being "fed" to it via Bluetooth and the GNSS Status App.

[AndrewMilanes]

Kayla, based on my experience during the purchase process of my R2, I am not at all surprised that your sales rep was misinformed.  I had to educate my Trimble rep on the capabilities and configuration I wanted in my R2.

So yes, as long as you setup your real-time configuration in the GNSS Status App, Collector will have no idea what the source or accuracy is.  Unfortunately I don't have a VRS subscription to demonstrate this right now.  In LA the service isn't free and I rented a subscription for a few weeks during a project but it has expired.

Since Collector does not have any GNSS accuracy or status reporting at this time, the only way to verify this would be an actual field test on a known monument.  I'll likely purchase a VRS subscription within the next month, so I'll be able to test it out then.