Just based on the shape, I was going to guess it's a
wind profiler radar, but those are silent and often have a large equipment van nearby. From the audio recording, I think it's a
SODAR. I've never used one, but it fits the descriptions I read online. It looks very similar to a
Remtech PA-05, Remtech being a French company.
Edit: found a working
datasheet link. It states 9 different frequencies, centered around 1 kHz. Sounds about right. Even the trailer looks similar, with the reflector stripe along the wheel well.