GPS accuracy issues when using external GPS with iOS

User Support Data Collection
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Aloha,

We pair our android devices with submeter external GPS receivers to obtain the highest accuracy possible for our GPS point submissions. I then approve/reject them for upload into our database based upon the Accuracy (m) value. Ideally, these values are between 0.2 m and 3 m.

I’ve recently begun experimenting with using an iphone for data collection. I’ve verified that the Lat/Lon coordinates supplied by the iphone to Enketo accurately reflect the coordinates from the submeter external unit, As such I would expect Kobo to log an Accuracy value in the 0.2 m to 3 m range. However, the accuracy value always reads “10” m.

Has anyone else encountered this issue with iOS? If so, do you know of a solution to have the correct Accuracy (m) value to be recorded into the Kobo form? I’ve searched through most of the threads to no avail, and I’m not encountering this disconnect with any of the other mapping apps that we use.

Thanks in advance for any advice.

Kevin

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Hi Kevin
Thanks for your message. I have a few troubleshooting steps to check whether this is an issue with the level of accuracy being noted at 10 meters even when it is below it (higher level)

  1. Check if this problem occurs when you use an android device with KoBoCollect
  2. Check the same with ODKCollect
  3. Try the same with Enketo on android based web browser?

Kindly feedback to allow for further investigation

Regards
Stephane

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Hi Stephane,
To clarify, the Accuracy (m) value is always correct when using an android device regardless of using Enketo android web browser or KoBoCollect.
The problem only arises when using an iphone. The external unit (EOS Arrow 100) is reporting a horizontal accuracy level of between 0.2 and 3m to the iphone in the iOS app (EOS tools pro), and it is sharing the precise lat/long coordinates with Kobo Enketo via Safari and/or Chrome, but it will not share the correct accuracy value.
Can you think of any other reason why the iphone will not share the horizontal accuracy value with the web browser? Have you heard of this issue occuring with other folks that employ Apple devices? Thanks again for your valuable input.

Kevin

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Hi Kevin
This is rather new. This may however have to do with the communication between the external device and the iPhone. In that case there is not much support we can provide by only hope that there is a user who has done this before. To ensure your topic reaches the audience with specificity, I am changing it to read GPS accuracy issues when using external GPS devices on iOS

Regards
Stephane

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Hi Kevin,
When you record your GPS are you connected to 1) internet and or 2) cellphone?
I tested the humanitarian server on my laptop and was in my flat with wifi and the gps landed 18.7 meters from where it is supposed to be. Ok, i am assuming if i go outside and stand away from walls the reading will improve - something i still need to test.

Then I disconnected the internet from the laptop and it hung - which i expected as the server is an online site.

Is there a way to download the humanitarian kobo toolbox onto a laptop so it can work where there is no internet and no cellphone reception?
thanks
Uma

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Hi Uma
If you want to collect GPS coordinates using online tools then you must be online; that is how browser based data collection works. You can download KoBoToolBox onto your computer but you still have to collect data using either a browser or a Collect application

Regards
Stephane

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