Compass Precision with DGPS

Question

I notice that even though my app is using a DGPS instead of the device's integrated GPS, when I use the compass to get to a known point it only brings me to within 1m of it -- is it possible to increase the precision of the compass when using DGPS?

It would be great if when using a DGPS the compass would allow sub-meter directions to a point.

ColinLawrence · Answer

@SandraDalton Some screenshots would help provide context, thanks! The reason I suggested other devices was to help narrow down what might be causing the problem for us.

Doing a little more testing on my end I see sub meter distances reported in Compass mode using iPhone or iPad and using the internal GPS, external Trimble R1 and external Juniper Geode. Unfortunately I dont have a GG04 to test with but it should behave similar to the Geode.

I am attaching an example from my iphone and geode setup.

File (1).jpg

SandraDalton · Answer

Hi Colin,

Unfortunately it doesn't matter if it works on other devices, as iPads are what are used at the company sites for collector/fieldmaps.

The DGPS we noticed the issue with is a Leica GG04 smart antenna that has been upgraded to bluetooth it to iOS.

Units are set to Metric, Coordinates to UTM, and Distance and Area are automatic.

I'll get some screenshots as soon as I can to post for you.

ColinLawrence · Answer

That is strange and perhaps its specific to iPad (I dont have one available at the moment); have you tried another type of device? I tried with an iPhone and Trimble R1 unit and I see units reported under a meter while in compass mode and a DGPS fix. See attached.

What type of external GPS are you using? What do your Units settings look like in the app? I am using "Metric" and Automatic for everything else. Thanks!

compass.jpg