PA8W's Radio Direction Finding Technology

Succesful RDF41 application by students of Rochester Institute of Technology:

A group of students of the Rochester Institute of Technology in New York succesfully finished their senior project using an RDF41.

The challenge they had to meet is to build an autonomous vessel that can home-in on a 121.5MHz EPIRB device,
a floating emergency transmitter that pilots or other crew members can use when they crash at sea.
Modern EPIRB's transmit an very short UHF signal as well to satellites that can provide a crude position to rescue teams.
The much weaker but constant 121,5MHz signal is used to home-in when the rescuers arrive in the destination area.
The idea of this project is the development of a small vessel with emergency supplies that could be dropped from a plane somewhere near the downed crewmember.
After the drop the vessel should set course to the EPIRB and bring the supplies to the victim so he can survive the time needed for rescue boats to arrive.

The students task was to create a working setup, however, for obvious reasons the final test was done in a swimming pool and not at sea...
Which is an extra challenge in radio direction finding because of the reflective metal in the surrounding concrete and structures.

But using an RDF41 and a scaled down VHF array, (things had to stay small) they managed to do the job in a very convincing way!

Succesful RDF41 application by students of Rochester Institute of Technology

They used a Bearcat portable receiver, and the RDF41's serial output for the directional information.
And very clever: They added heat sensors to detect the vicinity of the victim to cut the motors.
Of course the programme that gathers all information and makes the decisions and a lot of hardware was made by themselves.

Here's a short video of the final demonstration:

A job well done guys, congrats!

Cheers, PA8W.