GPS question

lacibaci

lacibaci

Well-Known Member
Joined
Mar 5, 2015
Messages
1,623
Reaction score
823
Country
United States
Is there a way to troubleshoot GPS? Today I got no lock for almost 10 minute trip.
Parked the car for a half an hour and on a return trip it was all good.
The module is attached to the windshield.
 
Yes, I did. I checked other days and it does take up to three minutes to lock. Is that normal?
A119 locks almost immediately.
 
anything up to around 2 minutes is expected from a cold start with any GPS, quite often it's a lot less though
 
I'm going to move it to another spot and see if that will help. Right now it is attached behind the black out area to the left of the rear view mirror.
 
The TTFF is commonly broken down into three more specific scenarios, as defined in the GPS equipment guide:

  • Cold or Factory: The receiver is missing, or has inaccurate estimates of, its position, velocity, the time, or the visibility of any of the GPS satellites. As such, the receiver must systematically search for all possible satellites. After acquiring a satellite signal, the receiver can begin to obtain approximate information on all the other satellites, called the almanac. This almanac is transmitted repeatedly over 12.5 minutes. Almanac data can be received from any of the GPS satellites and is considered valid for up to 180 days. Manufacturers typically claim the factory TTFF to be 15 minutes.
  • Warm or Normal: The receiver has estimates of the current time within 20 seconds, the current position within 100 kilometers, and its velocity within 25 m/s, and it has valid almanac data. It must acquire each satellite signal and obtain that satellite's detailed orbital information, called ephemeris data. Each satellite broadcasts its ephemeris data every 30 seconds, and is valid for up to four hours.
  • Hot or standby: The receiver has valid time, position, almanac, and ephemeris data, enabling a rapid acquisition of satellite signals. The time required of a receiver in this state to calculate a position fix may also be termed Time to Subsequent fix (TTSF)
 
The first case doesn't apply since the lock was acquired about an hour before the drive.
 
We'll see if this works. I'll report later.
IMG_20160904_234206.jpg
 
It would be nice if the GPS icon reflected signal strength. Or maybe something in the menu... The GPS module already provides this information so it should be relatively easy.
 
you didn't break a wire during flipping?
 
I re positioned the GPS module to upper right portion of the windshield and away from the evil dots. Don't know what kind of paint they use at Volvo but this module doesn't like it. So far the acquisition time in the morning (inside the garage) was under 2 minutes, mostly under 1 minute when outside - I can live with this.
 
You must log in or register to reply here.
Back
Top