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5 answers

The radar sends out radio waves in a 360 degree sweeping motion. When the radio waves bounce off of an object (a boat, ship, or whatever) it sends back the reflection of the radio wave which is received by the same antennae it calculates the time from being sent - to being received and will give you an accurate range. Depending on the size, and material of which it reflects off of, it will give you a stronger or weaker blip.

2007-11-19 11:30:08 · answer #1 · answered by Mad Town Ghost 2 · 1 0

You have most of the answer from the responses above but there are issues that are almost always overlooked and turn the usefulness of radar into a dangerous tool.

Radar is not a picture of what your chart looks like. Many people think that all you have to do is look at your radar and find a chunk of your chart that looks the same. Quite simply you never will. Radar can't see around anything so something like a point of land translates into a wide land mass rather than the small finger you would expect to see. If the entrance to the harbour you're looking for is behind that finger, you'll never find it.

Radar is a tool that measures "Relative Motion". It shows you how you're moving in relation to another object. If you have an island (something that doesn't move) on screen, than your direction and speed is about what you'd expect it to be. However if you have another boat on screen, you may have a problem.

You may have a target coming toward you from the upper left. That would suggest that you have the right of way and that they would have to avoid. BUT, they might be moving really slowly in the opposite direction and you are actually overtaking them. Now you're the burden vessel and have to keep clear of them.

Radar is a great tool but it takes proper training to fully understand what you're looking at. If you're looking to invest in one, that's great but don't think it's a simple matter of turning it on and going for a spin in the fog. Start out by using it on clear days so you can get a better picture of what it's trying to tell you.

2007-11-20 08:09:19 · answer #2 · answered by Larry M 4 · 0 0

I'm sure you have seen the radar "mast" turning in a circle onboard a ship or boat. Well, as it turns it sends out an electronic signal (some use micro waves) as those signals strike another ship etc, the waves bounce back off it and return to the sending unit. The unit "measures" the time it took to send and reflect back and converts that to a visual signal on the radar screen which tells you how far away the object is, and approximate size, speed (or not moving) etc. Normally this info is shown on a circular screen, with the sending vessel shown dead center, and the other object(s) are shown around it . Thinking of the radar display as a clock face with your vessel facing the 12 o:clock position, other objects will be displayed around you.

2007-11-20 07:33:31 · answer #3 · answered by randy 7 · 0 0

1) The magnetron sends a pulse of energy through the transmitter using either 3cm or 10cm waves.
2) The transmitter alternates between pulse generation and a 'listening' mode, whereby returned signals are detected and sent to the receiver, and the time difference between the last pulse and the return signal is used to measure the distance from the transmitter.
3) The transmitter rotates at a set speed, in order to both give a 360-degree return, and to update the receiver.
4) The receiver processes both the directional data and the distances at which recieved signals are detected. This is translated into a video or CRT image on the screen.

2007-11-19 11:30:26 · answer #4 · answered by benthic_man 6 · 2 0

i think its sends out a signal and if its interrupted ir know smoehtins their or it measures how long it takes for the signal to get back

2007-11-19 11:26:15 · answer #5 · answered by melovearmy 2 · 0 1

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