Time to first fix

buphone · Occasional Visitor Joined: Aug 01, 2005 Posts: 36

The time to first fix for the mk2 gps unit seems to vary from a few seconds to a few minutes. What is it doing in that time and why it varies?

CJackel492 · Regular Visitor Joined: Mar 15, 2005 Posts: 210

MARViN2003 · Posted: Mon Jan 09, 2006 12:01 pm Post subject:

It seems to lock on better when stationary as well.

Basically it searches for the satellite signals and then calculates it's position from those signals. It needs to get at least 3 reliable signals for it to lock-on.

buphone · Occasional Visitor Joined: Aug 01, 2005 Posts: 36

Thanks for the replies. I searched this website and others. Here is something that helped me understand and fits with what people here are saying:
http://www.pocketgpsworld.com/ttffcomparisons.php

It seems that TTFF will increase if:
* I switch the antenna on in a different place
* I move while it is trying to do the first fix

buphone · Occasional Visitor Joined: Aug 01, 2005 Posts: 36

Further to my last post, I would like to ask a question about TTFF in a new location.

Here is a common scenario. I have tomtom mobile 5. I get home in my car and turn tomtom off. I take both the phone and the antenna into the house. I don't bother to turn the antenna off because it switches off by itself after a while. Thus the antenna could be switching off inside the house.

In the morning, I go out to the car. I turn the antenna on and start tomtom.

So the location change involves a few metres. It also involves a change of signal strength (weaker inside the house). Are either of these changes significant enough for me to modify my routine?

MarkHewitt · Posted: Wed Jan 11, 2006 2:37 pm Post subject:

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