Radar Spotter - Sensor calibration

What is it?

In order to function properly the Radar Spotter app needs your device's compass. The compass is some sort of an electronical sensor, that measures the direction of the earth's electromagnetic field. Like the needle of a real compass, it shows to the magnetic north pole. The problem is, that we are surrounded by any kind of electromagnetic fields nearly anywhere that disturb the functioning of this sensor. Even your phone is emitting massive amounts of 'electromagneticity', so the sensor needs what is called a calibration. Simply speaking, this is done by some sophisticated electronics and algorithms all the time. Because the disturbing fields are random, one can get rid of them by averaging the signal of the sensor over time and keeping a correlation between the devices orientation relative to gravity (for which is also a sensor inside your device!) and the averaged signal.

How to do in real world?

Even if it sounds difficult, to calibrate your device's compass it is nothing more needed than moving it around. Some people say that writing the number 8 three times with your phone does the job. Other say, rotating the phone three times on each of the three axis does the trick. This does work with 90% of all android devices, since they all rely on very much the same set of sensors inside.

Proof of thoerem

If you are unsure if your device is calibrated, or if you think something is really wrong with directions when using our app, what to do then? We did also think of that problem and found a pretty simple solution how you can check it. (It only works on a sunny day.) Try the following:

There is an augmented symbol for the sun (orange ball)) when you are using the camera view of the spotter tab. The symbol is shown at the position where your compass matches with the calculated position of the real sun at your current location and time. If the compass is calibrated correctly, the augmented sun position and the real sun's position should be nearly the same.

WARNING! DO NOT POINT YOUR PHONE'S CAMERA DIRECTLY INTO THE SUN DIRECTION. IT MAY CAUSE SEVERE DAMAGE TO THE CAMERA-CHIP! HOLD A FINGER ONTO THE CAMERA-HOLE DURING THE PROCESS AND CHECK WITH YOUR CAMERA BEING COVERED.