How to convert the obtained positioning information to latitude and longitude?

[Kenny]

Hello, All,

I want to use the GPS positioning function of the nRF9160, currently using the "nrf/samples/nrf9160/gnss" sample for testing, the type used is GNSS_SAMPLE_ASSISTANCE_NONE.

After I get the data, I want to judge the accuracy of the positioning.

I found the deviation to be a bit large.

Is there any additional conversion needed to get the actual latitude and longitude?

What tool can I use to get the actual location based on latitude and longitude?

This way I can get the error of the actual measurement.

For example, the following is the data location data I get, based on NCS 1.8.0:

$GPGLL,2240.11407,N,11402.12129,E,091646.16,A,A*6A

How to get the actual location based on it?

Using the map to locate the position found that the position is very different, so I can't be sure if the data is correct.

Hope to get your reply soon, thank you!

[Charlie]

Hi Kenny,

There is always a deviation between your device's actual location and the measurement data you get from different positioning technologies, so the problem becomes which level of accuracy do you expect for your application with consideration of the cost? 

GPS electrical specification table on page https://infocenter.nordicsemi.com/topic/ps_nrf9160/gps.html#overview provides an overview of nRF9160 positioning accuracy under different modes. 

We also provide cloud-based location services with different accuracy levels, which you can find from Location Services | nRF Cloud Docs.

Best regards,

Charlie

[Kenny]

The deviation I mentioned is not the deviation between various positioning methods, but the deviation between the location data I obtained at a certain location and the location data I found by searching the map is very large, far greater than the deviation described in the specification book.

So I have this question.

[Charlie]

Kenny said:

the deviation between the location data I obtained at a certain location and the location data I found by searching the map is very large

Every positioning method has its own accuracy. This is exactly what you mean here. Please be aware of the accuracy mentioned in the specification is an average value. The real accuracy will vary depending on your testing environment. I am not sure how large the deviation is in your test. I suggest you test the nRF9160: GNSS — nRF Connect SDK 1.8.0 documentation (nordicsemi.com) sample outdoor under the open sky and wait longer time to check the result. 

GPS.gov: GPS Accuracy

Best regards,

Charlie

[Kenny]

OK, Thanks for your reply!