You find 3 files of the form #_samplerate_frequency_bandwidth.iq:
These files were captured over the air via a software-defined radio. You have a suspicion these broadcasts contain valuable information. As such, you have decided to try to determine the contents of each file.
NOTE: The format of the flag is ATR[], for example: ATR[foobar]. The flag must be submitted in full, including the ATR and square bracket parts.