radar

[van der vart]

talking about radar, what's stagger ratio?

[rustybh]

Pulse Repetion Frequency (PRF) Stagger stagger is used in many airborne MTI radars to reduce the effects of "blind spots".

The PRF (no of pulses per second) of the radar is "staggered" through a set or psudeo random series of values according to the type of radar and it's expected usage.

I believe in this case the ratio refers to the no of levels of stagger available in the radar architecture.

[van der vart]

thank you very much

but i'm still not very certain of what the term means.

if the stagger ratio is 40/46 , what does that mean?

[van der vart]

anybody please?

[spekesoftly]

OK, I'll have a go, but I warn you now that radar theory is not my specialisation!

As well as detecting aircraft returns, primary 'raw' radar will often be 'cluttered' by ground returns. A device called MTI (moving target indicator) can be used to discriminate between stationary and moving targets, so that only the aircraft are displayed. A drawback to MTI is that it can suffer from 'blind speeds'. I seem to recall that multiples of 70kts is not uncommon for an ATC radar - so in theory aircraft flying at 70kts, 140kts etc, would not be detected. A solution to this is to 'stagger' the pulse recurrence frequency. I can only guess that 'stagger ratio' is the ratio of staggered to non-staggered pulses.

Probably a load of old cobblers, so please forgive my fading memory.:ugh:

[van der vart]

thanks for trying.
sound reasonable