If not actively tracking will the Mini stop tracking location or is the GPS antenna not very sensitive.

I've been experimenting with my new Mini trying to understand a few things.

When the unit is on, and it's not actively tracking should it maintain a location fix? I was hiking in very wide open terrain with it clipped to my side belt loop (and outside my pocket).

Twice I looked at it to notice that is was waiting for gps on the location page. After 10-20 seconds it would show lat/long on the location page.

Is this normal? Meaning does this REALLY need a clear view of the sky, or does it 'idle' when it's not actively tracking?

  • This is normal. Like all dedicated iR devices, the Mini tries very hard to conserve battery. The biggest power drains are the backlight and the radios - GPS, Iridium, BlueTooth, ANT+.

    A clear sky view is a good thing for both GPS and Iridium. It is more important for Iridium, in that there are fewer satellites in view and the transit time for any given satellite is short. Your body is mostly water, which does a fine job of blocking both sets of satellite signals. Although not necessary, for optimal results the conventional wisdom is to carry the unit on a pack strap at shoulder level.

    One other tip. It's a good idea to wait for the initial fix (after power-up) before stowing the unit, and before setting off. 

    In my experience, the unit does not acquire a GPS fix unless it needs to. When tracking, it acquires a fix when it needs to send or log a track point. Sent points go out over the Iridium network. Logged points are stored on the device until you sync, when they are uploaded to the web site. Typically, you set the send interval to be longer than the logged interval (if you are logging at all). The minimum send interval depends on your plan, but will not be less than 2 minutes. The minimum log interval goes all the way down to 1 second. If you set a log interval of 30 seconds or less, you will receive a warning that this causes the GPS radio to remain on at all times - a real battery suck.

    If you are navigating to a waypoint, following a route, or using TracBack, the unit acquires a fix at intervals which are theoretically short enough to facilitate navigation. Still, even on the navigation screen, you may see the occasional "waiting for GPS" message. In these situations, I don't know how frequently the unit acquires a fix.

    The same thing is true of sitting on the location screen. The unit updates the location when you first enter the screen. After that, I am not sure how often it updates your position. But it does not maintain a continuous fix. 

    The Iridium radio is on only when necessary to send something (sent track point, message, newly marked waypoint, weather request, etc.), or when you ask for a mailbox check. The unit also does an automatic mailbox check once an hour. There is also some passive periodic "listen" activity which is much less battery-intensive.

    If you are paired with a phone, I do not know how frequently the BT radio is used. If you are not paired with a phone or not using the phone at present, you should turn BT off. Same for the ANT+ radio and pairing with a watch or other device.

  • Thank you for taking the time to respond. And good stuff to know as I get used to the unit's functionality.

  • Excellent information    Thanks for sharing this.   I think that may help to explain why I always get the “poor GPS” alert every time I initiate sending a message.  I was assuming that the unit was always connected to GPS. It makes sense that it attempts to save battery by only acquiring a fix when needed.  seems like smart engineering.

    also, this is the first time that I have understood that there are two separate satellite systems used by the unit, GPS for location and Irridium for communication.  Correct?

  • Correct. GPS for location, Iridium for communication. Iridium does not provide location services.