Returning to college, I budgeted a hardward allowance for a few items to aid in the study such as a few cisco devices, laptop memory for virtualization and one "playful item" that I feel is a great tool for security study, the HackRF.

The HackRF is a SDR ( Software defined radio) capable of receiving and transmitting at half duplex between 1 MHz to 6 GHz covering a large frequency for analyzing and development. My interest in this field of study is the overwhelming spectrum allocations geographically, which carry many interesting over air communications and protocols. 

While the HackRF is a powerful open source tool kit, I find enjoyment in free range scanning frequencies surrounding you and used the information collected to identify the source and it's use. Satellite imagery can be obtained from downlink satellites such as the NOAA weather satelites.