A few months ago, I came across a German company (their web site enede with .de) who makes a multi-beam ultrasonic rangefinders for air. It resembled the Sick LIDAR, but it was a SONAR. On the outside, the device looked like a cylindrical puck or a pot (it didn't look miniature).
I came across it in a industry rag, iirc. I can't seem to find it again. Does anyone remember a device that might fit the description?