How can I know if the GPS coordinates are from internal GPS chip or from wi-fi , cell phone network, or USB GPS?

Question

Using the latest sample code for getting GPS coordinates, I can get a lat/lon position and accuracy of about 350 feet.  Is there any way to know whether the GPS data came from the gps chip set, cell data connection, or from Wi-Fi router address? Does decoding the accuracy give a clue?

Is a GPS via USB supported in Metro?  I plugged in via USB  and Microsoft GPS Receiver from company store (UBLOX USB GPS) and even though the hardware recognizes it, I cant tell from the API call whether the actual GPS data is coming from the USB attached GPS device or otherwise.

Answer 1

Victor,

I will look into this for you.

Best Wishes - Eric

Answer 2

Victor,

http://msdn.microsoft.com/en-us/library/windows/apps/windows.devices.geolocation.positionaccuracy.aspx

Is the PositionAccuracy enumeration 0 or 1?  The USB GPS you have should work fine.  I will try and find one to test.  Maybe place it in a laptop that otherwise does not support location?

Best Wishes - Eric

Answer 3

Victor,

I do not see a method to know which unit the data is coming off of.  However the above setting could make an accurate device show less accuracy to improve power consumption etc...

Best Wishes - Eric

Answer 4

Whether using a laptop with wifi OR the build tablet(with wifi, att data network, and GPS), I always get a reading of +/- 350 feet accuracy from the coordinates even though I requested high accuracy.  Are you seeing the same thing?  i.e. are you getting any different results? The documentation indicates that you can request high accuracy but "the information returned may not actually be any more accurate." I guess it's one of those wait and see what hardware actually gets built kind of thing.

the device enumeration for the USB GPS shows it is connected to COM7 and since serial port (physical and virtual) is not supported in WinRT, that it seems like USB devices are useless in any Metro ARM only hardware.  Is that right?

 

Answer 5

Victor,

Windows 8 will support the same USB devices as Windows 7 does.  However WinRT has no support for USB as you say. 

Best Wishes - Eric

Answer 6

Victor.

The 350 foot accuracy would appear to be coming from the WiFi.  The build tablet does not have a GPS unit.  I am not sure why the streets and trips unit is not working.

Best Wishes - Eric

Answer 7

Victor,

Could you try the USB GPS unit on the laptop with WiFi disabled?

Best Wishes - Eric

Answer 8

I have tried this here and I also get the 350 feet.  This is the reading for WiFi.  I did install this driver:  http://www.u-blox.com/en/drivers-a-middleware/usb-drivers/windows-7-driver.html

Answer 9

Victor,

350 feet is the reading you get back for wifi.  IP address is aprox 50 kilometers.  I would say your GPS unit is not installed properly.

Best Wishes - Eric

Answer 10

How can I tell if the GPS unit is not installed properly?  I installed the updated driver from the link and noticed that from PC Settings - Devices it now reads: u-blox 5 - GPS Receiver.  It used to read COM5 before I installed the updated driver.  I turned off wi-fi hoping my app would get the GPS coordinates from the GPS device but it doesn't get any location data at all.  Do you get any data or readings using the UBLOX GPS USB receiver?  thanks.

Answer 11

Is the PositionAccuracy enumeration 0 or 1?   Could you try setting it to 1 if it is not already set that way?

Best Wishes - Eric