Hey guys,

I have a unusual project. I have a customer needing a radar system to detect boats from offshore. Its for a underwater farm that he is worried about poachers. I am going to have high powered camera set up for zoom and night vision. But its a remote island so i need notification when a boat comes within a coordinate square. The unfortunate part is if i put just a radar system in, it will constantly notify when a boat just drives through. I just want to know when a boat has stopped there for 30 mins or an hour. this will allow me to reduce false alarms. I will be remotely accessing the camera and is motorized to allow for control. I just need some way i can make the radar follow or detect a boat in the guarded zone for 30 mins. If i just put a 30 minute delay on it, it would notify me only after 30 mins, weather the boat is still there or not correct? I would need a 30 min delay and have it know it is still the same object. Tehre are systems out there that can do all this, but its a deference between $2500 and $60,000.

Anyone have thoughts on how i can initiate a delay so i dont get false alarms on it constantly

 

So the radar scans a sector and if there is a target in the beam then the time to the reflection tells you how far away it is and you know the dish angle, so you know where the target is. A computer could then track a target or targets and signal if one had been in the target area for the 30 minutes.

In theory, relatively easy, however there will also likely be reflections from waves and getting it to ignore those would be much harder.

 

Use the distance alarm from the radar and use this to activate circuit.( depending on type of radar but most have it (part of anchor alarm)
Anchor alarm indicates I am moving or an object or an object moves into my safety ring.
If a ship is within xxx Nm you may assume that is going in your direction now evaluate the distance output by cpu/mpu when distance goes down it will trigger your alarm mechanism. When distance goes up a reset will follow.

 

All of the responses are going to imply questions about the output signals from the RADAR. Have you selected a RADAR unit yet? If so, please post whatever information there is.

ak