Exciting Update: All of us that worked on this project got a paper published in the 2013 Interdisciplinary Engineering Design Education Conference (IEDEC).
Link to paper: IEEE Xplore PDF

My senior design project at GVSU was to design and build a software defined radio for use in amateur astronomy. The project was sponsored by Dr. Doug Furton of GVSU's Physics Department. Senior projects at Grand Valley consist of interdisciplinary groups of students working on industry sponsored small projects. In our case, our group consisted of myself (a computer engineer), Sean Bredeweg (an electronic engineer) and Dan Soberal (an electrical engineer).

The SDR was designed to pick up a ~1uV signal centered at 20.1MHz and had a bandwidth of 1MHz. The receiver was designed to pick up RF emissions from Jupiter, similar to NASA'a RadioJove project. The project used Analog Devices AD9460, a 16-bit, 105 MSPS analog to digital converter, along with Digilent's Nexys2 FPGA board. The FPGA board also housed the Cypress FX2 high-speed USB transceiver used to transfer data to the PC. On the PC's side of sides, GNU Radio was used to perform all the signal processing required.

For documentation and more technical descriptions of the project, see here:

For all the source code and schematics of the project (FPGA code, USB transceiver code, GNU Radio code, etc), see here:

Here's a video of a signal sweep test using a signal generator:

Here's a video of test using a terrible copper wire antenna (hence having to turn the signal generator to 0.5V)

In this demo, we show our "radio astronomy" mode, which plots a moving average of signal intensity over time:

This video demos a mixer board we constructed at the sponsors request to mix the signal down to audible range: