We have tested the gps in a field away from tall building and while driving in the street. We faced the low GPS accuracy issue. lgt-92 give up to 100m wrong location. Is anyone have faced the same issue ?
No. What about weather?
Weather was good and i checked number of satellite it was 8. I am using it with US915.
What accuracy are you seeing ?
Also what firmware version are you using ? this what i am getting for a static position of lgt-92
As every gnss fix with the lgt92 is more or less a cold fix (afaik), the accuracy can sometimes be bad due to this energy save mode.
Maybe there is a way that the gnss module could work in hot fix mode to decrease time to fix and increase accuracy with a firmware update.
From that map, some of the position fixes may well be close to 100m out, but the majority look much closer than that. Lots of high trees around too, they wont help.
If the GPS is being run in hot fix mode then running it for longer than the time when it first aquires a fix should improve accuracy at the expense of power consumption, but thats really an issue for the company who are selling the tracker to addess.
If the GPS is run in cold fix mode, with no backup of satellite data, and postition is reported as soon as it gets a fix, then the location variations seem normal to me. Again running the GPS for longer would improve accuracy.
Also difficult to tell from picture but how tall is the building at bottom? If tall you may be in satellite shadow at times and also may suffer from deflection/reflection issues increasing path lengths and peturbing resuts. positioning looks to be quantised so assume your are using a payload format such as LPP?
I have tested lgt-92 in a hot fix with firmware 1.4 but it still gives me more than 100 meters error. I also run it for a longer time but it did not improve the accuracy. In parallel I have another GPS u-blox neo-6m. I am using it with arduino. It is giving me 2 meters accuracy in the same parking lot.
I have checked the firmware how Dragino parsed a NMEA code to get latitude and longitude. I did not see any issue in the parsing equation. Do you guys think there is a bug in the firmware which is changing NMEA code randomly before it parse into latitude/longitude or its a hardware(GPS chip) issue? LGT-92 is using Quectel L70-RL.
@Jeff-UK building is almost 50 feet tall and yes it is LPP format with 11 bytes. u-blox gps is giving me 2 meters accuracy on the same location.
If your claiming that your LGT-92 tracker always has at least a 100m postion error, then perhaps its time to raise it with Dragino, its their product after all.
I have 2 lgt92 since 6month and I didnt see such high and continously offset.
How do you get the Position? Directly over USB/serial or over payload in TTN?
Works your payload decoder correct?