GPS Signal Strength

[VK4ADC]

My GPS receiver (U-Blox 6-based) continues to pump out data even in the absence of actual GPS signals and creates basic GPGGA and GPRMC strings based on its internal clock. Sure, it is more accurate when GPS is available but is still pretty close if it is not.

There are a number of the data points that you can use to see if the GPS is actually seeing sats and the quality of the fix but using the U-Centre software and checking the AGC is a good option for actual signal level, as suggested previously.  Actual signal level is probably not necessary for most position and timing applications but if you want to dig deep, why not ?   My GPS2Time application uses only the GPGGA and GPRMC streams.

It seems that the support of reading that AGC level is a U-Blox proprietary command sequence so will only work with that brand device, ie. it is not generic to all GPS receiver devices, something others thinking about using such a feature need to be aware of before they get too far into it.

My 2.2c ... (includes GST)

Doug