Software Defined Radio for OSINT
Here is a 45 minute video of Catbird Linux being set up to use software defined radio for OSINT (open source intelligence). Essentially, use a radio server in the area of interest and find the broadcasters, military, and other spectrum users. Listen to them and take a measure of the situation. Get a feel for what is normal and what the regular patterns are. Look for changes and non-normal behavior. Make recordings or screen captures of what you find.
SDR Shortwave 2021-04-23
We find here that mediumwave in Ukraine has only a few stations on the air, music and talk, with lots of powerline noise. Military and other non-broadcasters are out there on shortwave - you just need to observe and find them. Look for stations such as The Buzzer / NZhTI / UVB76 as part of your near-warzone radio exploration.
Listening from India, there was more noise and some stations seeming to focus on normalcy despite the health crisis happening...
From Korea, the Philippines and Japan, one can hear where the regular broadcasters are, along with muzak and propaganda from the DPRK (North Korea). Chinese fishing boats and other maritime operators seem to gather in the 8700 through 9400 kHz range.