safisafo
Posts: 1
Joined: Mon Jan 14, 2019 12:51 am

Accuracy of GPS

Mon Jan 14, 2019 12:58 am

Hi. I'm using the SIM7600E module to take my latitude and longitude, but the result given is located like 30km away (very bad accuracy, like 3º), but it doesn't almost change. I'm running it indoors, is this normal?

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topguy
Posts: 5117
Joined: Tue Oct 09, 2012 11:46 am
Location: Trondheim, Norway

Re: Accuracy of GPS

Mon Jan 14, 2019 10:40 am

Can you link us a datasheet for the product you are using, because none of the modules with that name that turn up in Google actually have a GPS, its a 4G modem.

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bensimmo
Posts: 3590
Joined: Sun Dec 28, 2014 3:02 pm
Location: East Yorkshire

Re: Accuracy of GPS

Mon Jan 14, 2019 3:15 pm

Something is wrong OR theit is the way you are reading the NMEA coordinates*.
It should get you within 10meters without a problem.. normally after a bit of time.

Apparently some models can have GPS.
https://www.waveshare.com/wiki/SIM7600E-H_4G_HAT


*There are different methods of representing coordinates.
But I should be degrees and minutes iirc
DDMM.MMMMM

Try http://www.hiddenvision.co.uk/ez/ to change to a different system and use that in your map.
Also if anything like the UK and you are sat in the meridian line then watch out for - E & W

pfletch101
Posts: 304
Joined: Sat Feb 24, 2018 4:09 am

Re: Accuracy of GPS

Tue Jan 15, 2019 2:55 pm

bensimmo wrote:
Mon Jan 14, 2019 3:15 pm
Something is wrong OR theit is the way you are reading the NMEA coordinates*.
It should get you within 10meters without a problem.. normally after a bit of time.
I would not bet on this GPS accuracy (or even working at all) when run indoors, which the OP notes is his situation.

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bensimmo
Posts: 3590
Joined: Sun Dec 28, 2014 3:02 pm
Location: East Yorkshire

Re: Accuracy of GPS

Tue Jan 15, 2019 4:24 pm

pfletch101 wrote:
Tue Jan 15, 2019 2:55 pm
bensimmo wrote:
Mon Jan 14, 2019 3:15 pm
Something is wrong OR theit is the way you are reading the NMEA coordinates*.
It should get you within 10meters without a problem.. normally after a bit of time.
I would not bet on this GPS accuracy (or even working at all) when run indoors, which the OP notes is his situation.
If it gives coordinates then it has a lock on a few satellite. So it has a a good radius to work with, maybe not 10 meters, but within 100m no problem. NOT 30km's ...
which sound like a unit mix up on the mapping program.

pfletch101
Posts: 304
Joined: Sat Feb 24, 2018 4:09 am

Re: Accuracy of GPS

Tue Jan 15, 2019 4:44 pm

bensimmo wrote:
Tue Jan 15, 2019 4:24 pm
pfletch101 wrote:
Tue Jan 15, 2019 2:55 pm
bensimmo wrote:
Mon Jan 14, 2019 3:15 pm
Something is wrong OR theit is the way you are reading the NMEA coordinates*.
It should get you within 10meters without a problem.. normally after a bit of time.
I would not bet on this GPS accuracy (or even working at all) when run indoors, which the OP notes is his situation.
If it gives coordinates then it has a lock on a few satellite. So it has a a good radius to work with, maybe not 10 meters, but within 100m no problem. NOT 30km's ...
which sound like a unit mix up on the mapping program.
You may be right - if it is a GPS device. However, the OP also hasn't responded to topguy's implied question, noting (correctly) that the device the OP says he is using is a 4G modem with no GPS capabilities. Whatever he is using to get his location may be returning the location of the first router in his transmission path that admits to its location!

drgeoff
Posts: 8899
Joined: Wed Jan 25, 2012 6:39 pm

Re: Accuracy of GPS

Tue Jan 15, 2019 5:30 pm

The SIM7600E module does have GPS capability

See https://simcom.ee/modules/lte/sim7600e/ . Under General features "GNSS gpsOne Gen 8B;standalone;assisted,XTRA"
See https://simcom.ee/documents/SIM7600E/SI ... 20V1.1.pdf pages 1 and 5 for mention of GNSS antenna

But does whatever the OP is using have a GPS antenna connected to the SIM7600E?

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bensimmo
Posts: 3590
Joined: Sun Dec 28, 2014 3:02 pm
Location: East Yorkshire

Re: Accuracy of GPS

Tue Jan 15, 2019 5:37 pm

I posted a link to one, it has GNSS, aka GPS.

I doesn't mean it may not, but await to see.

EDIT , to above post, the Waveshare one is that chipset I linked to.
Also as it GNSS it has GLONASS, Beidou etc like my Ublox8. These connect indoors much better than my ublox6 which can fail to get a lock.

Anyway, back to await feedback.

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