Weird GPS reading on Asset Tracker when no GPS fix

I’m using an Asset Tracker with an Electron, using the supplied demo code and the 0.0.1 version of the supplied GPS library. I’m reading the data from it with Node-RED, and posting the geo data I find on the “Worldmap” node in Node-RED. Everything built remarkably easily, and I can see a dot on the map. So far so good.

In some cases when I have no GPS fix (a blinking red light) I get a 1 return from the “call gps” function, and a weird result from the SSE return: 42.229233,0.000000 (a good latitude but a bad longitude).

When the device has a proper GPS fix it does the proper thing, and indeed I’m successfully getting correct reads when the GPS is happy.

Just wondering if this is a known problem, whether I hit a corner case I will need to deal with, or if it’s time to cycle power on the device to deal with what is just a transient problem. It would be useful in decoding GPS response in marginal conditions to get some other simple indicator of GPS signal quality (number of satellites seen?)

I’m also looking at @benagricola 's https://github.com/benagricola/tracker which has some more functions, if there are other people who have taken the sample code and run with it I’m interested.