You can basically hook up an antennae to your laptop and start receiving images from space. This DIY guide from Public Lab amazes me.
The NOAA satellites have inbuilt radio antennas that transmit the data collected by the AVHRR instrument on a frequency in the 137 MHz range. To minimise interference between satellites, each NOAA satellite transmits on a different frequency within the 137 MHz range.
Your antenna is a sensor. It catches electromagnetic waves and transforms them into an electrical current i.e. an electrical signal. All antennas are tuned to specific frequency ranges meaning that they receive or transmit these frequencies best. Most antennas are directional.
I need to try this.