I wanted to try out something unique with my RTL-SDR on my cruise around the Azores Islands. The Azores are an archipelago about 500 miles off the coast of Portugal in the Atlantic Ocean. They were an important stop for trans-Atlantic sailors, as it was a convenient rest between Europe and the new world. Many sailors including Christopher Columbus and Henry the Navigator used the Azores resupply point. After the advent of engines, the Azores have been bypassed, much like Route 66. Now they serve only for destination for trans-atlantic sport sailing, and tourists.

The National Oceanic and Atmospheric Administration (NOAA) has been imaging Earth with satellites since 1975. These satellites are used to monitor weather patterns, climate change, and natural disasters. The data is transmitted to Earth in real time from these satellites, and can be received by anyone in the signal path.

In this post I will be collecting and displaying telemetry from the NOAA 18 satellite. The NOAA 18 satellite is in a polar orbit, meaning it orbits over the north and south pole. It takes images of the earth, and imediately transmits the image at a rate of 360 lines per minute. The data from this satellite is transmitted at 137.9125 MHz with Analog picture transmission APT.