Quick Tip: Calibrate your phone GPS

A mobile device is an excellent tool for backcountry use.

I regularly use a phone for photos or videos, books, star charts at night, identifying peaks on the horizon, point forecasts via NOAA, and, of course, navigation. 

At this point in my outdoor experience, I look at the mobile device as merely another piece of gear in my kit. And how I use the equipment impacts the experience. And not the tool itself.

As a well-known author, Chris Townsend states in different articles:

How communication technology is used in the hills is up to the individual of course. There are no rights or wrongs. I see no reason not to check emails and social media or even make phone calls if you find it satisfying any more than I can see a reason not to read in the hills (and I have been told at times that it’s ‘wrong’ to carry a book). The key is for you to control it and not the other way round. If it becomes intrusive and you think it’s spoiling your enjoyment the answer is simple. Switch the damn thing off!

 

 ( Emphasis  mine ).

As with any tool, knowing how to use the tool correctly is imperative for the effective use of that piece of equipment, however.

Recently in New Mexico, the local SAR had difficulties finding a person that another hiker called in the GPS coordinates for on backcountry rescue.

Why did the SAR group encounter difficulties?  Hard to know for sure.

But some possibilities include:

  • Different formats were different from one group to another.  The first hiker may have given a format differently.  Most SAR organizations use a decimal format, whereas GPS-enabled apps often use a different default format. If the SAR group transcribed the format and did not realize they needed to convert it in decimal format, the location’s off.

  • Different datum.   The first hiker might have used NAD27 vs. WGS84 for the SAR group, which means a different location for the subject despite the GPS coordinates.

  • At night, and in rough terrain, hard to find people.   Obvious esp if using data discrepancies.

Rough terrain on Mt. Peale. PCO Joan.

But there’s another possibility, and a possibility I found out the hard way: You occasionally have to recalibrate the internal compass of your phone GPS to get accurate location data.

I noticed this when using a star chart app and when it did not line up with the moon correctly. The star chart app immediately told me that my compass needed calibration. Oddly enough, any navigation software I’ve used does not have this seemingly mission-critical reminder/warning.

Electromagnetic interference, other electronic devices, or even your phone’s protective casing can all cause your phone to give inaccurate location data.

So, my tip? I spot check the compass calibration periodically. And I ALWAYS check before any mission-critical navigation. 

It is easy to recalibrate the compass on both the Android and iOS platforms and only takes minutes.

On Android via Google:

If your blue dot’s beam is wide or pointing in the wrong direction, you’ll need to calibrate your compass.

  1. On your Android phone or tablet, open the Google Maps app Google Maps.
  2. Make a figure 8 until your compass is calibrated. You should only have to do this a few times.
  3. The beam should become narrow and point in the right direction.

Compass calibration

On iPhone via AccuraWare

From Lifewire

  1. Enable the Compass Calibration service:
    • Click on the Settings icon.
    • Select Privacy.
    • Select Location Services.
    • Select System Services.
    • Turn Compass Calibration ON.
  2. Open the built-in Maps App and follow the on-screen prompts to get an accurate location reading.
  3. Press the lower left side arrow till it points up.
  4. If your compass is not calibrated, a Calibration Circle screen will pop-up and you will be able to calibrate the compass by filling out that circle with figure 8 movements in the air.
  5. At the end of this process you will note that the blue line of sight in the Maps application is pointing to the correct direction.
  6. Your compass is calibrated.

_____

A mobile device and a built-in GPS tool make a powerful and useful piece of kit. But you need to know how to use the tool effectively. And an occasional recalibration of the GPS compass is part of the knowledge.

 

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Mike Cunningham
Mike Cunningham
22 days ago

I never knew that. It might explain why a program said I was 150 ft off the trail when I was standing on it. Thanks, Mags.