Search radar has massive lag, low refresh rate

[some1]

According to Razbam's own manual and the information posted on the forum, the radar should complete full scan in 1.3 seconds. But in the current DCS version it doesn't match this number and there are multiple problems with targets depiction in the Mig-19.

1. The targets on the screen are not updated every 1.3 seconds, but much less frequently, only once in roughly 3-4 seconds.

2. On top of that, there's also more delay built into the system. For example if I turn right, the target starts drifting to the left on the screen. When I reverse the turn, the target keeps drifting to the left for another 1-2 cycles, before it comes back to centre. So in total, the information shown on the radar screen is 5-10 seconds old. Check the attached track.

3. The same delay is also visible in the vertical. It takes 5-10 seconds for the radar to switch the target between "above" and "below" indication after I change pitch. Also shown in the attached track.

4. The vertical sweep line that travels across the screen is the only thing that updates in DCS every 1.3 seconds, but it only paints the ground clutter. It has no correlation with target updates whatsoever. And if it is meant to depict the radar antenna "sweep", then it's also completely incorrect due to this particular radar construction.

The search radar has two antennas spinning together at constant speed, one pointed slightly upwards, the second downwards. Together they scan the whole area in front of the aircraft, one full scan equals one rotation of the assembly. So it's actually two sweeps in each full scan, with a brief pause in-between, when the assembly is oriented perpendicular to the flight path. It also means that the targets that are at the same level as the radar will be caught by both antennas.

So where does this 1.3s for the full sweep comes from in Razbam manual?  @foxbat155 discussed it here: https://forum.dcs.world/topic/192125-mig-19-ground-radar-return-test/?do=findComment&comment=3758423 but that math does not check out. If the assembly really spins at 80 RPM, then one scan should take 0.75s, not 1.3s. Even faster than what Razbam manual states, and much, much faster than the current implementation in DCS.

Either way, the Mig-19 radar in DCS fails at the primary task for which the thing was created in real life, and that is performing intercepts at night or in low visibility. With 5-10 seconds lag as it is now, getting into position behind the target that you can't see is more a matter of luck than anything else. You can try it for yourself, I've attached a simple mission with clear night, AWACS and two targets in front of you flying straight. Have fun 

 

 

PG_night_intercept_MiG19.miz

zMigRadar.trk

Edited January 25, 2024 by some1

[foxbat155]

You right, search antennas block unit spins with a speed of 80 revolutions per minute, this gives 360 degrees swept every 0.75 seconds ( 60:80=.75 ). Of course when the target is on the radar level, return signal is given by both antennas and then the position of the target symbol on the screen should be refreshed every 0.35 sec. My mistake.

Edited January 25, 2024 by foxbat155

[f-18hornet]

Reported.