Why is GNSS data sometimes blank?

When GNSS positioning fails, you can see a - mark in the Latest Location column of the device.

Also, when you check the GNSS data detail in Ecotopia App or check the downloaded GNSS data, you can see the values of Longitude and Latitude are both 200.00000.

The main reasons for positioning failure include:

• Poor GNSS signal
  Dense forests, strong magnetic fields, being close to open waters , etc. can cause GNSS signal blocking or interference, and leads to positioning failures.
• Antenna Damage
  The external antennas of some models or even GNSS modules are broken due to force majeure like bird’s pecking or predators, etc..