Mil air would be a good start. Especially with Ouffutt close by. All of Ouffutt LMR is now encrypted. Last thing I heard about NE NG is that they use VHF and are encrypted. I have heard their helicopters on low band, frequencies listed in the database under NE EMA. If you have HF capability HF is always nice to listen to for Military. You will have to do a lot of searching for frequencies. Many frequencies are not posted. Some do get deleted from the database here on RR due to their policy, only by request of a commander.
The main thing you will have to do is search, search and search. Then listen, listen and listen to try to identify the user.
Some are easy to identify. Some us their squadrons nickname for unit IDs. There are some websites with military aircraft call signs and what base/squadron they are from.
The NE ANG/NG may be on the statewide system when it is done.
