Phone app: Chart your GNSSr

Discussion about software such as GSAK, OziExplorer etc, as well as all things hardware, GPSrs, laptops, PDAs, paperless caching, cables etc
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MavEtJu
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Phone app: Chart your GNSSr

Post by MavEtJu » 03 November 17 7:32 pm

The local reviewer in here in NSW, Australia wanted to do an experiment:

> Attach your GPS receiver to a tripod. Turn it on and record its position every ten minutes for 24 hours. Next day, plot the 144 coordinates your receiver calculated. What do you suppose the plot would look like?

> Do you imagine a cloud of points scattered around the actual location? That's a reasonable expectation. Now, imagine drawing a circle or ellipse that encompasses about 95 percent of the points. What would the radius of that circle or ellipse be? (In other words, what is your receiver's positioning error?)

On iOS you don't have access to the GNSSr system, it all goes via the CoreLocation services. That includes the improvements via Wifi-assist and Mobile Telephony triangulation. You will be told the accuracy, but you won't be told where it came from. Does that make it a worse system? I don't know, but I know that my iPhone generally brings me to the right location for caching.

See http://ios.me/app/1303544506/chart-your-gnssr for the app.

See https://github.com/MavEtJu/testGNSSr for the code.

Edwin

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