topic Re: Collector 10.4.0 not reporting accuracy correctly? in ArcGIS Collector Questions

Collector 10.4.0 not reporting accuracy correctly?

AlisonWalker — Fri, 07 Oct 2016 17:50:36 GMT

Using the latest Collector with an R2 CM Edition receiver. Seems to work great, but I'm concerned about the accuracy reporting. I've lost my connection to my base station a couple times which reduces the accuracy of this receiver from 1 cm to a couple of meters, but Collector does not give me any indication that there is a problem and just lets me continue collecting data. It continues to report that I am getting less than an inch of accuracy when that is not the case. Has anyone else seen this issue? I'm going to do more extensive testing to reproduce the issue before I submit a case, but I wanted to see if anyone else has seen this and resolved it already?

Re: Collector 10.4.0 not reporting accuracy correctly?

EricErtl — Tue, 11 Oct 2016 16:14:36 GMT

Hi Allison,

I have run into this issue as well. I am not sure if it is Collector that is losing the connection as much as it is the receiver losing Bluetooth connection to iOS. One way to alert the user of a lost connection is to set the required accuracy to the threshold you deem acceptable. Then, when in the app, if you try to acquire a location above that required accuracy the user will be alerted that the location is invalid. Please see screenshot. #collector10.4.0‌

Re: Collector 10.4.0 not reporting accuracy correctly?

MiaogengZhang — Tue, 11 Oct 2016 21:00:39 GMT

As Eric suggest, required accuracy setting is a good way to get an alert to this situation. You can also use GNSS Status app as additional test tool to check reported accuracy. It should be the same as the accuracy reported at Collector.

Re: Collector 10.4.0 not reporting accuracy correctly?

AlisonWalker — Tue, 11 Oct 2016 21:10:04 GMT

Thank you both for the feedback. The issue is that Collector continues to report 1-inch accuracy even when GNSS Status is reporting much worse due to the loss of real-time correction. So even if I have Collector set to only collect data at a certain level of accuracy, Collector just lets me keep going even though the real-time has been dropped and GNSS Status is reporting 10 feet. Worse yet, the metadata records whatever Collector is reporting, so I might end up with metadata showing 1 inch of accuracy when in fact it’s nowhere near that.

Re: Collector 10.4.0 not reporting accuracy correctly?

MichaelDavis3 — Wed, 12 Oct 2016 00:29:09 GMT

Is GNSS Status the Trimble app?

I notice a mention here:

http://anatumfieldsolutions.com/2016/03/14/submeter-gnss-field-tested-compared/

They reference an issue with Trimble reporting a higher accuracy level in their app than the data would support.

Re: Collector 10.4.0 not reporting accuracy correctly?

MiaogengZhang — Fri, 14 Oct 2016 05:26:47 GMT

Alison,

Do you say GNSS status is reporting 10 feet accuracy but Collector shows better accuracy? You see inconsistency accuracy report between Collector and GNSS status app. Is my understanding correct? Do you see it all the time or only when it loss real-time correction?

Thanks

-Morgan

Re: Collector 10.4.0 not reporting accuracy correctly?

Andrew-Bowne — Fri, 14 Oct 2016 17:35:07 GMT

I too have noticed "suspicious" accuracy readings. I have collector connected to a GeoXH (which is connected to our base station). Terrasync is reporting 4.5cm accuracy whereas Collector is reporting between 8-10 feet. From a visual perspective I am right on, however Collector is telling me I am a lot further away. Any ideas why?

Re: Collector 10.4.0 not reporting accuracy correctly?

AlisonWalker — Fri, 14 Oct 2016 20:12:20 GMT

Yes, exactly. So I have some data that was collected this morning that had the real-time purposely disconnected to see what would happen. For 3 or 4 minutes, Collector continued to report 1 inch accuracy and record that metadata in the metadata fields long after (like 2 minutes is long in this case ) GNSS Status was reporting much worse.

However, on this test, it did eventually respond and report the proper estimates. Just seemed like it was slow to react or refresh. I wouldn't be too worried about this if it didn't continue to record incorrect data into the metadata.

I will fully admit that I have not had time to do thorough enough testing to determine if the problem is really Collector or if, in fact, the bad data is coming from GNSS Status. I will try to come up with a better test plan and keep you updated, but if you'd like to see the data or any screenshots, let me know.

Thanks,

Alison

Re: Collector 10.4.0 not reporting accuracy correctly?

MiaogengZhang — Tue, 18 Oct 2016 23:13:19 GMT

Alison,

I will do some internal test about this.

-Morgan

Re: Collector 10.4.0 not reporting accuracy correctly?

MiaogengZhang — Tue, 18 Oct 2016 23:16:34 GMT

Andrew,

I think if you look at NMEA output from GeoXH, probably it doesn't report GST sentence, which is required for accuracy report. If no GST is reported, Collector will do some rough estimate. You can find more info at

GPS receiver support—Collector for ArcGIS | ArcGIS

-Morgan

Re: Collector 10.4.0 not reporting accuracy correctly?

Andrew-Bowne — Thu, 20 Oct 2016 12:18:54 GMT

Do you know of an easy way to write out a sample of the NMEA output to see if GST is reported?

Re: Collector 10.4.0 not reporting accuracy correctly?

GaleShea — Mon, 24 Oct 2016 22:08:01 GMT

I know a request for an auditory warning when corrections are lost has been asked for in a future release if possible, as well.

Re: Collector 10.4.0 not reporting accuracy correctly?

GaleShea — Mon, 24 Oct 2016 22:09:51 GMT

Any new testing results to report...? thanks!