An RBRconcerto Alti has a RBRalti sensor which outputs distance and echo timing. Only distance is reported by the RBRconcerto.
Full, in-situ derivation of distance from echo timing requires an average speed of sound over the path used by the sound.
Distance is a 'pure' derived parameter which has its own channel assigned to it, but there is no underlying measurement hardware for distance itself; it simply uses the outputs of the echo timing channel and the average speed of sound setting. This makes its specification rather sparse: there are no coefficients in either of the 'c' or 'x' groups; all that is needed is to specify the indices in the 'n' group.
In our example:
- n0 is the index of the echo timing channel, 2 in this example,
- n1 is the index of the average speed of sound channel, value in this example, ie the default setting.
The distance is calculated as follow:
where
- Te is the echo timing (round trip) in milliseconds, value(n0).
- ASS is the average sound of speed, value(n1) (refer to "settings avgsoundspeed").
Example commands:
<< calibration 1 type = alti00
( Confirm the channel type )
>> calibration 1
<< calibration 1 type = alti00, datetime = 20130401120013, n0 = 2, n1 = value
( Request confirmation of everything )