Quote:
Originally Posted by Letum
There is certainly a theoretical minimum range for all radar.
It's determined by pulse length.
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I looked up some pulse lengths for some radar on aircraft around that time, and they all seem to have pulse lengths no longer than 2.5 us. This works out to a 325 m minimum range.
In the KTB's reports suggest that the escorts have difficulty picking up surfaced u-boats by radar at about 1.5 km. The then suggest that you turn perpendicular to the course of the escort to escape. It seems that this is dangerous and unreliable (but they were having some real problems fighting come Mar '43). To get a 1.5 km minimum range would require a pulse length of 10 us, which seems to be a pretty long time, especially b/c they would probably switch to a shorter pulse length to start dealing with the U-boat as it got closer anyway.
Is there any indicator that there were mechanical issues that would force a minimum range? Say that the apparatus is high up and cannot "see" targets below a certain angle from horizontal, therefore it results in a minimum range?
Also, does anyone know what the destroyer AI would do when it loses contact at ~1.5 km? I am assuming it would head to the last known spot as quickly as possible to look for you. How would visual contact start working at this point?