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 Novice From United Kingdom, joined Aug 2012, 90 posts, RR: 0Posted Tue Sep 18 2012 17:03:25 UTC (3 years 8 months 1 week 2 days 18 hours ago) and read 3999 times:

 Primary Radar; Wavelength of 30-50cm Pulse length 4 microseconds (us) Horizontal beamwidth 1.7 degrees Aerial rotation 5 RPM Can anyone explain what the difference the between wavelength and pulse length of a primary radar? Cheers
 Fabo From Slovakia, joined Aug 2005, 1245 posts, RR: 0 Reply 1, posted Tue Sep 18 2012 17:27:54 UTC (3 years 8 months 1 week 2 days 17 hours ago) and read 3987 times:

 wavelength is the distance where the wave pattern is repeating (eg. pattern is up, down, down back up to zero, and then again - like a sinusoide), as in, the distance that the signal will make in about the pulselength. Pulse length is time in which one wave pattern is emmited from the antenna, and frequency is how manny patterns are emmited in one second. 4 microseconds is therefore about 250Hz if I calculate correctly.
 The light at the end of tunnel turn out to be a lighted sing saying NO EXIT
 9VSIO From United Kingdom, joined Dec 2006, 729 posts, RR: 2 Reply 2, posted Tue Sep 18 2012 19:43:19 UTC (3 years 8 months 1 week 2 days 15 hours ago) and read 3956 times:

 Pulse length is also known as period, right?
 Me: (Lining up on final) I shall now select an aiming point. || Instructor: Well, I hope it's the runway...
 HaveBlue From United States of America, joined Jan 2004, 2169 posts, RR: 1 Reply 3, posted Tue Sep 18 2012 20:54:26 UTC (3 years 8 months 1 week 2 days 14 hours ago) and read 3929 times:

 Quoting 9VSIO (Reply 2):Pulse length is also known as period, right?

If that's true, then I hate being around my girlfriend when she's on her 'pulse length'...

 Here Here for Severe Clear!
 saafnav From South Africa, joined Mar 2010, 343 posts, RR: 1 Reply 4, posted Tue Sep 18 2012 21:26:16 UTC (3 years 8 months 1 week 2 days 13 hours ago) and read 3915 times:

 Quoting HaveBlue (Reply 3): If that's true, then I hate being around my girlfriend when she's on her 'pulse length'...

OWM.... Nearly chocked on my coffee! Hate those damn Pulse Lenghts...

 On-board Direction Consultant
 David L From United Kingdom, joined May 1999, 9645 posts, RR: 42 Reply 5, posted Wed Sep 19 2012 01:40:01 UTC (3 years 8 months 1 week 2 days 9 hours ago) and read 3865 times:

Radar doesn't transmit continuously, otherwise it would be difficult to tell which part of the signal is being reflected. Instead, it sends a short pulse, stops to listen for a return from that pulse then repeats. The pulse is a short transmission of a signal at a certain wavelength. The pulse length is the length of time each pulse is actively transmitted.

In the example in the OP, each pulse is a signal with a wavelength of 30-50cm which is transmitted for 4 microseconds at a time.

See the diagram here: http://meteorologytraining.tpub.com/14271/css/14271_58.htm

 Quoting 9VSIO (Reply 2):Pulse length is also known as period, right?

The period is the inverse of the frequency. Since frequency is measured in Hertz, or cycles per second, the period is seconds per cycle - i.e. how long it takes the wave to go from one peak to the next.

 Jetlagged From United Kingdom, joined Jan 2005, 2620 posts, RR: 25 Reply 6, posted Wed Sep 19 2012 11:34:15 UTC (3 years 8 months 1 week 1 day 23 hours ago) and read 3710 times:

 Quoting 9VSIO (Reply 2):Pulse length is also known as period, right?

It's the wavelength which is also known as the period.

 The glass isn't half empty, or half full, it's twice as big as it needs to be.
 Novice From United Kingdom, joined Aug 2012, 90 posts, RR: 0 Reply 7, posted Wed Sep 19 2012 13:01:47 UTC (3 years 8 months 1 week 1 day 22 hours ago) and read 3678 times:

 Thanks for that explanation David L
 speedbird128 From , joined Dec 1969, posts, RR: Reply 8, posted Sun Sep 30 2012 06:27:23 UTC (3 years 7 months 4 weeks 4 hours ago) and read 3242 times:

 Quoting David L (Reply 5): it sends a short pulse, stops to listen for a return from that pulse then repeats

= PRF.

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