Compass from GPS and position of sun

Read today in the new Scientist (2015-8-8 p13) about a $100 app that combined the GPS position, the sun position and the time to a compass. The idea is quite old but apparently with modern technology a high resolution is possible. They claim 1/100th of a degree!

The concept: If you have a sundial, the shadow tells the time as it points to the north. time = f(sun, north);

If you "inverse" the algorithm you can get north = g(sun, time);

The idea is that the (12) hour finger of a clock rotates "exactly" twice as fast as the sun. So by creating a (24) hour finger (from GPS or RTC) and align that with the shadow the sun, the top of the "watch" would point exactly to the north. Although this works only on sunny days it seems to be a nice project for a student looking for a project.

Seems to be a half truth to me.

What if you're in South Africa or some other place down under ?

Choose the down-under release available on SA, Australia, Southamerica, and sometimes on Antarctic. 30% off for purchasing both modules. In case it's out of stock, perhaps one will have to move reversely by handstand as a workaround. Release v2 is announced to provide a jumper to stick for down-under mode (down-under the backpane).

robtillaart: Read today in the new Scientist (2015-8-8 p13) about a $100 app that combined the GPS position, the sun position and the time to a compass.

ridiculously overpriced

Could be a problem if close to the equator.

Weedpharma

Hi, The scouts have it all worked out.

http://www.scoutsociety.org/repository/orienteering/Finding-North.html

Tom... :)