Author Topic: invalid time of Last GPS Fix  (Read 129 times)

Offline Andrew Heard

  • Master of Locus
  • ****
  • Posts: 514
  • Thanked: 14 times
    • View Profile
  • Device: Samsung Galaxy A5 Oreo, Samsung Galaxy Note 8 KitKat
invalid time of Last GPS Fix
« on: June 13, 2018, 03:20:03 »
Tested with Locus Pro 3.31.0 & 3.31.1
Note below Last GPS Fix:

This field is not always reliable, and Locus no longer detects in a timely manner when GPS fixes are lost.

To demonstrate: I obtain valid GPS fixes then put the phone in a faraday cage (eg. microwave oven!) to ensure there are no further fixes/ GPS signals but the time will still increment for a further 15 seconds or so before a lost GPS notification is observed (heard). The Last GPS Fix field cannot be real/ possible. The time should immediately stop if no signal is received.

I made this simple test to demonstrate a more real-life experience when the phone was taken inside my home but over 10 minutes later there was still no lost GPS notification - GPS icon on main screen was still green. No Wifi or cellular radio was on/ enabled at the time either. I then turned on the display and a few seconds later there was a lost GPS notification and the GPS icon turned orange. It could not just be a coincidence.

Unfortunately and maybe this is Android "fooling"/ telling Locus there are valid location updates? In which case there may be few/ no options to improve the situation.
« Last Edit: June 13, 2018, 03:29:13 by Andrew Heard »
 

Offline menion

  • Administrator
  • Professor of Locus
  • *****
  • Posts: 10721
  • Thanked: 166 times
    • View Profile
    • http://www.asamm.com
  • Device: SGS7
Re: invalid time of Last GPS Fix
« Reply #1 on: June 13, 2018, 08:34:25 »
Hello Andrew,
interesting tests, thanks.

Firstly, are you using settings > GPS > Google Services assisted location? If so, suggest to disable it because I can imagine it may really give some positive values even a while after GPS stops receive new data.

You 10 min. field test ... did you do this with latest 3.31.1 version? I noticed the similar problem so in 3.31.1 it should be improved a little bit.

Generally ... "valid GPS fix" time value a while after device stop receiving GPS location data is possible and I'm sure it will be in hands of the device, not Locus. Anyway "green icon" that indicate that all is ok and missing "GPS lost notification" is definitely a problem of Locus Map app. I'll be watching it more carefully.
Ideas, wishes, problems
Advanced topics, public discussion, sharing of knowledges, testing beta versions: you're here!
 

Offline Andrew Heard

  • Master of Locus
  • ****
  • Posts: 514
  • Thanked: 14 times
    • View Profile
  • Device: Samsung Galaxy A5 Oreo, Samsung Galaxy Note 8 KitKat
Re: invalid time of Last GPS Fix
« Reply #2 on: June 13, 2018, 11:46:03 »
Thanks Menion.

settings > GPS > Google Services assisted location:off
yes with latest 3.31.1 version
100% reproducible

Before the recent major GPS code changes am sure that taking phone/Locus into house would result in 'GPS lost notification' within a minute. Although not extensively tested it seems a notification may never occur if display is left off in recent versions.