I am searching for a tiny radar transmitter/receiver that can detect a slow-moving motor vehicle but only vehicles moving directly towards the radar source (doppler?). Detection range would need to be at least 100 feet and speed detection range would need to be down as low as 10mph or up to about 50mph. The radar transmitter/receiver would need to be run by a small lithium battery (Smart phone or small laptop).

I am open to alternate ideas like deep infra-red light or even LIDAR, but radar has a very long, very successful history with detecting moving metal objects.

Thank you for your time and attention.

 

Good luck with the radar. Yes it is quite possible, all it takes is money. Radar plus vision seems like the best combination. Radar for exact distance plus rate of closure. Video to see the path of approach. They are doing it with those computer driven cars, it sort of works at 55MPH. At slower speeds you have a much better chance.

 

You may have to contact the company directly but the HiLink HLK-LD306S is about as close to perfect as you will find. (considering the very small amount of information you’ve provided). The company is very responsive, and you can purchase directly from them via AliExpress.

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It is a millimeter wave (24GHz) radar, about $50 in single pieces with a serial interface (UART) that will provide the speed information directly. It‘s rated for 10-250k/h. They have a dev board for it, and do recommend using it to get started, but I can’t find it on AE. However, as I said, they are very responsive and a message to the company will get a helpful response.