Frequency has been used for EAM's from airborne command post aircraft for some time, currently the E6B Mercury series, mostly. I've caught them on 311.000 and 321.000, too - but only rarely. I've actually never heard one on 323.800, nice catch. This afternoon I had a WBFM/MPX Northstar downlink burning from what I'm guessing was an airborne command post on 230.900. Are you in the Midwest? I'm just outside of Chicago. The footprint on these signals can be hundreds of miles in radius.
My understanding is these transmissions are one the backups to the Milsat satellite feeds for the folks down in the ICBM silos. Happy Scanning! - Ted
And finally, here's a cute little HF discone out in front of the Titan Museum. A sign described that if you are an amateur radio operator how you could contact the local amateur radio club for an opportunity to actually use the antenna while on site.
To answer chgomonitor's question, I'm on the CT coast next to the CT River, very far from any silos. The signal came in strongest when I turned my DPD LP to the south, Maybe it was from W105 area, south of Long Island.