Sound echo locator.
Echo Locator functions in the same way as a radio location system, a radar, does except that sound waves are in use instead of electromagnetic waves, in which sense it could be called a sonar.
The app attempts to plot a map of obstacles around the user and can be used in darkness.
The app emits sounds of special pattern that propagate through air and bump into everything on their way and then, being reflected, return to the mic.
The app then distinguishes these sounds on their return and the distance to objects gets determined by the time the sounds were traveling away from speaker and then back to the mic.
The app does the above procedure many times per second drawing a radial line each time.
So, if speaker and/or mic is moving, each radial scan line on the screen will show the new picture.
If speaker and mic move, i.e. rotate, synchronously with how the plot is drawn on the screen then together all radial scan lines make a map of reflecting objects around.
In closed environments, like in a room, sound waves get reflected from every wall, floor and roof several times and that makes it difficult to see a clear picture of what happens in the plot.
Proven by experience that a good mic is essential and that mics from headsets often do better than built in mics.
But the problem arises that once you plug in a headset you end up with no loud sound.
The solution, and generally good practice, is to use a separate device as a sound emitter only with the same app running on it, possibly with no mic.
In this kind of installation sound emitter device is placed near the mic of listening device which can be located distantly as wire to the mic allows.
Sound emitter device and the mic comprise the moving part of the system.
Listening device connected to the mic serves as a location station.
Echo Locator uses speaker and microphone.
Maximum distance: 2.5 m
Minimum distance: 0.5 m
Detectable distance difference: 0.06 m
-- automatic adjustment
-- works in noisy environments
Rocket start instructions:
1. Make sure that the sound volume is low.
2. Press SCAN.
3. After a few seconds a graph will appear progressing clockwise.
4. Adjust sound volume so that picture in the graph becomes distinguishable.
Use reflector dishes, external speakers and microphones.
Move the locator system to match current direction displayed.
Keep ears away from loud unnatural sounds like those produced by the app.