Satellite Chasers

Use an omnidirectional double cross antenna to pull images from NOAA weather satellites

Comment

Inspiration

Each member of Satellite Chasers is a member of the UC CubeCats (http://uccubecats.org/), an undergraduate student organization dedicated to the education of members through the construction of Cube Satellites, and High Altitude Balloons. We wanted to learn more about antenna design, and construction and how satellite communication works. This will aid us in designing a ground station to communicate with our satellite Project Leopard that will be launched into Orbit within the next few years.

What it does

Our Omni-directional double cross antenna receives signals on the VHF frequency band at around 137 MHz. The antenna is constructed of steel cable, copper fittings, and COAX cable all made for under 35 dollars.

How we built it

The antenna was constructed by mounting quarter wavelength steel dipoles on a wooden support structure and then connecting them to 4 coaxial cables that were then connected to a computer via SDR#.

Challenges we ran into

The largest challenge that the group overcame was adjusting the sampling rate of the system to that of each individual satellite that flew over. Furthermore the cross connection of the quarter wavelength steel dipole antennas and splitting of the coax cables was a challenge. There were no wire strippers available to strip, and disassemble 3/8" coax cable so a new process had to be created to strip and separate the core and conductive shielding or the cable.

Accomplishments that we're proud of

As a team we are proud that we were able to sample images from a NOAA weather satellite for under 35 dollars. The team worked extremely well together and was able to prototype and build the antenna within 12 hours of the start of the hackathon.

What we learned

  • How to calculate and design an antenna for proper gain of a desired frequency
  • How to use SDR# to trans-code images from an analog signal
  • How to decode a wav audio signal from a satellite into a static image

What's next for Satellite Chasers

  • Automation of a control system to sample satellites without a human user to initialize satellite contact (beacon signal for connection).
  • Apply the knowledge learned from the project towards the completion of the UC CubeCats ground station that will be used to communicate with satellites in Low Earth Orbit (LEO) over VHF and UHF frequency bands.
  • Design an antenna for use at higher frequencies and possibly communicate with Geo-Stationary Satellites

Built With

Share this project:

Updates