YourITronics

The dsPIC30F4012-based Doppler Radar System enables you to track speeding motorists in your neighborhood. The well-designed system generates a microwave energy burst with a 10-GHz transceiver. The microwave signal bounces off of a moving vehicle and the frequency (Doppler) shift is measured to determine its speed.

I must say this is the first DIY Radar system I’ve seen well documented. It’s definitely worth a try if you’re into this kind of projects.

Doppler Radar System Tracks Speeding Vehicles: [Download Project] - [View Project PDF] - [via]

Improving upon typical ultrasonic systems, which are ineffective when used around sound-absorbing materials like padded furniture, the Infrared Radar uses infrared light to create a radar rangefinder. Additionally, this radar works faster than ultrasonic radars and improves object identification by measuring the range as well as reflectivity of the target. The speed and single-cycle execution of the ATmega8 microcontroller eliminate the need for external components.

Infrared Radar: [Via]