RS+ Loosing FIX

[mark.brown]

Hello All,

I am using rs+ base & rover on a site that has clear view of the sky, some days i can keep a fix for the entire day and other days I can loose my FIX for extended periods of time. Below are the links for my ubx files for yesterday. I lost my fix between 10 and 11 am.

raw_202010021015_UBX.zip

raw_202010021444_UBX.zip

I feel as tho I am loosing my fix due do some type of interference. Quite often when I loose my fix my handheld radio (136-174 MHz) will squelch. There is a 138 KV line within 100 ft of my base and also a pumphouse building that has a Yagi antenna (not sure of the frequency) within 200ft.

Thanks,
Mark

[liudmila.slepova]

Hi Mark,

Thanks for sharing the files! I’ll check them and get back with the news.

[liudmila.slepova]

Hi Mark,

Thanks for your patience!

@mark.brown

I feel as tho I am loosing my fix due do some type of interference. Quite often when I loose my fix my handheld radio (136-174 MHz) will squelch. There is a 138 KV line within 100 ft of my base and also a pumphouse building that has a Yagi antenna (not sure of the frequency) within 200ft.

Would it be possible to share the base correction log and position log when the receiver lost Fix? It’ll help me check whether the rover received the base’s corrections and if there were any disruptions. The position log will show us the exact time period when Fix was lost.

The electric lines nearby might have an effect on the reception of the GNSS signal. So it’s better to keep the receiver away from it if possible.

I’ve checked the rover’s logs you shared with us. The first log was recorded between 10:16 and 13:45 GPST. You can check the screenshot below. During this period, there are only three satellites with high SNR (G06, G17, G19). To calculate the Fix solution, the rover needs to have at least four common satellites with the base. To be considered a signal of good quality, the satellite’s signal needs to have SNR above 45.

The second log was recorded between 14:45 and 18:54. From what I see, during the whole survey, only four satellites have at least good quality (G05, G12, G13, G29 for a short period of time in the beginning). There are frequent cycle slips on all signals which might be the reason of being too close to the electrical lines. That’s what makes the signal to be disrupted or delayed.

Could you please specify why you have only used GPS satellite system? Our default recommendation for the GNSS selection is GPS + GLONASS + Galileo + SBAS + QZSS at 5 Hz. The results might be improved when you use more GNSS system signals as the receiver has more data to work with.