SatFinderAndroid Version #version# Help

SatFinderAndroid is © Copyright 2015, P. Lutus.

SatFinderAndroid is free, open-source and is
licensed under the GPL. And there are no ads.

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source code and more information.


SatFinderAndroid is a program that locates geostationary satellites and aids accurate satellite receiver dish pointing. It's used by professionals who install satellite dishes in homes and businesses, and it's also used by people like RV and yacht owners who, while traveling, must realign their satellite dishes on a daily basis.

Quick Instructions

More Use Details

Limitations and Use Strategies

Since this program was first released, a great number of new Android devices have been designed and marketed, many with poor position sensing abilities and compass reliability. As a result, for some Android devices, even though the computed satellite positions are very accurate, the SKYVIEW feature of SatFinderAndroid won't work very well, for reasons beyond the author's control.

To maximize the usefulness of the SKYVIEW feature, try rotating the entire Android device in three independent axes to calibrate its compass. Then, specifically for the SKYVIEW feature, try different display orientations. Some Android devices function better in a "landscape" orientation (wider than tall), others in a "portrait" orientation (taller than wide), and in some cases a 180 degree rotation of the device produces a better SKYVIEW display. The key to having the best device orientation is that the blue horizon line, and the compass bearing indications, will stay synchronized with the camera image reasonably well.

Some devices won't be able to use the SKYVIEW feature very well at all, and for this the author apologizes. This application is much more dependent on the hardware details of a specific Android device than most applications, and this special view mode may not work at all with some devices.

Again, for all Android devices that have acquired a geographic position, this application's computed satellite positions are very accurate.

Technical Description

SatFinderAndroid is the most recent incarnation in a series of satellite-related applications I've written over about a decade, starting with Satellite Finder (a.k.a SatFinder), and an online version of SatFinder, uncleverly named Satellite Finder Online. But when I first got an Android device and realized it had the ability to locate itself as well as sense magnetic bearings and local elevations, I realized this would be a perfect platform for SatFinder.

SatFinderAndroid produces satellite pointing angles in this way:

  1. The program acquires a location for the Android device. This is acquired either from a network positioning method, or GPS. The results can be seen on the LOCATION tab.
  2. The program lists all geostationary satellites and popular receiver dish models on the TARGET tab, and allows the user to select any number. This gives the program target locations to point to.
  3. With the results acquired in (1) and (2) above, the program computes azimuth (both true and magnetic) and elevation angles for the selected targets, at the device's location.
  4. Using the result acquired in step (3), the program uses magnetic and level sensors to create sighting displays on the SATCOMPASS and SKYVIEW tabs that allow the user to locate target satellite positions in the sky (or establish a pointing angle for a satellite receiver dish).

Geostationary satellite geometry and pointing is not mathematically difficult, because the satellites are stationary with respect to Earth, they're all lined up over the equator, and they're all at the same altitude. Other, seemingly less important things are are actually more difficult, like computing a magnetic declination for any location where a satellite position might be needed (for comparison with a hand bearing compass or an Android device's magnetic sensor), or creating a convenient display of azimuth and elevation angles for a given target.

Until this program was written, dish installers needed to compute sighting angles for each desired satellite in advance of a field outing to a particular location, then carry a hand bearing compass for azimuth and and an inclinometer for elevation, to have any chance to optimally position a receiver dish. But with SatFinderAndroid and an Android device, installers have the entire process in their hand — a complete list of satellites, a way to locate themselves, and sensors to help point the dish.