I have a Decatur Si-2 http://ghawgood.com/pdf/radars/si2.pdf I would like to set it up so that I can view the speed on my computer using the Serial Monitor for the Ardunio Uno.
How can I do this? Or can I?
Why do you need to go through a Arduino board? Just use a serial port on your PC, or if you don't have such a port get a USB RS-232 serial cable for cheap and process the data directly on the PC. You can use any general purpose PC serial terminal program of which there are several nice free ones. For Windows I like Brey terminal.