Sonar vs. ultrasonic ranger

[Electronics4you]

Hi There,

Is a sonar and an ultrasonic ranger really the same, or what is the difference?

https://www.acroname.com/robotics/parts/R254-SRF235.html

 

[Nigel Goodwin]

Hi There,

Is a sonar and an ultrasonic ranger really the same, or what is the difference?

https://www.acroname.com/robotics/parts/R254-SRF235.html

In this case it's the same, 'personally' I would prefer to see 'sonar' used for audible range units (like the 'ping', 'ping' on submarine films), but it's commonly used for any vibration system in the air (or water).

The example you posted was actually well in the RF spectrum, but used vibrations in the air rather than electromagnetic waves.

 

[oldtimer]

Sonar for long range underwater comms. uses frequences in the 10Khz. range
ultrasonic is 20Khz or more. I worked on sonar for a few years in the North Sea on transponders used for surveying oil rigs into position. The receive freq. of the transponders was 9 Khz and they responded on 8-16 Khz. Each one had a 4 bit code hard wired in so we could talk to any individual or group. This was how Brent "C" was surveyed in around about 1975.

 

[Electronics4you]

Thanks, here is a strange explanation of how to reduce ground clutter.

The pattern up and down (relative to the picture in the book – looking at the component side with wires on left) is not symmetrical. The sonar is much more sensitive to objects below boresight. So if you are mounting your sonar vertically (not side-by-side), mount it up-side-down. And in any case, aim the sensor UP about 30 degrees or more to avoid the ground. Probably the mounting supplied can be bent.
https://www.robot-electronics.co.uk/htm/reducing_sidelobes_of_srf10.htm

Could someone draw a sketch about what's meant.