It's CODAR. Radar applications used to measure coastal currents. See
the following URL:

http://www.thecoolroom.org/instrumen...ment_codar.htm

Merry Christmas,

Mike

On Dec 25, 9:21�pm, msg wrote:
Has anyone made any progress investigating the persistent chirp
or sweep signal heard around 4800 kHz and elsewhere? It is
about S2 to S3 here in No. MN tonight and S9+/-20db in NC/USA
as heard on an internet receiver there.

Michael