SU27 : Difference between SRC PD and SRC PD HDN

Hey guys !

Some one can explain what is the difference between SRC PD and SRC PD HDN please? :D

Thx you a lot guys and I wish you all a pleasant grind

I don’t play jets(yet) but I’ve recently had a bit of interest in learning about them and saw this tutorial about radars in WT, SRC PD HDN is the Head On mode for the radar.
SRC - Search, PD - Pulse Doppler, HDN - Head On


Overal, if you don’t go into the specifics, PD, or MPRF, is overal much more useful, but PD HDN (HPRF) has some advantages when it comes to long range headon aspect detection.

Specifically on the N001 radar on the Su-27:

  • ± 900 m/s velocity detection + tracking
  • 0.5-100km range detection
  • Includes a notch filter (all near 0 m/s returns are attenuated)
  • Notch filter becomes inactive in lookup (I think)


  • ± 1200 m/s velocity on tracking
  • 50-1200 m/s velocity on detection (search)
  • 9-100km range detection
  • No notch filter, so clutter is present near 0 m/s region (which means notching targets can be tracked, if there is high enough SNR (signal-to-noise ratio).

Thx you a lot guys for sharing this !

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Thx mate for you’r answer you are the best o7

hello mate can you send documents and references for these?

There’s not really a good document right now that explains it clearly, there is one radar spreadsheet but I am not sure if it’s maintained and it doesn’t include all information. I get the informatin straight from the war thunder datamined files and general knowledge from the radar mechanics through in game , YT videos, etc. The particular linked page has it set to all the sensor type equipment, such as radars.

If you were talking about IRL documents and references, I do not have them. This is specifically only for in game.

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i see . thank you mate