You normally think of ELINT — Electronic Intelligence — as something done in secret by shadowy three-letter agencies or the military. The term usually means gathering intelligence from signals that don’t contain speech (since that’s COMINT). But [Nukes] was looking at public data from NASA’s SMAP satellite and made an interesting discovery. Despite the satellite’s mission to measure soil moisture, it also provided data on strange happenings in the radio spectrum.

While 1.4 GHz is technically in the L-band, it is reserved (from 1.400–1.427 GHz)  for specialized purposes. The frequency is critical for radio astronomy, so it is typically clear other than low-power safety critical data systems that benefit from the low potential for interference. SMAP, coincidentally, listens on 1.41 GHz and maps where there is interference.

Since there aren’t supposed to be any high-power transmitters at that frequency, you can imagine that anything showing up there is probably something unusual and interesting. In particular, it is often a signature for military jamming since nearby frequencies are often used for passive radar and to control drones. So looking at the data can give you a window on geopolitics at any given moment.

The data is out there, and a simple Python script can pull it. We imagine this is the kind of data that only a spook in a SCIF would have had just a decade or two ago.

Jamming tech is secretive but powerful. SMAP isn’t the only satellite to have its mission unexpectedly repurposed.