IRIS-T SLM discussion

Machinery of War Discussion Ground Vehicle
4936

CIRCM is the 2 deg spread one?

4937

I was going by these two comments for the 2° beam opening/divergence:

2° beam opening isn’t even a laser anymore in the common sense but more a directed lamp.

According to a short search, a DIRCM laser should have a beam divergence of 0,03 to 0,12°, so 2° is too big by a factor of ~17 to 67.

1 Like
4938

Can you try with 0.25 degrees?

4939

That are many tables…

Beam Spot diameters in "centimeters"
Distance 0.03° 0.12° 0.25° 1° 2°
100 m 5.2 20.9 43.6 174 349
250 m 13.1 52.4 109 436 873
500 m 26.2 105 218 873 1745
1 km 52.4 209 436 1745 3491
2 km 105 419 873 3491 6982
3 km 157 628 1309 5236 10473
Energy reaching the target from a 200 W pulse laser in "watts"
Distance 0.03° 0.12° 0.25° 1° 2°
100 m 200 14.5 3.34 0.209 0.0522
250 m 37.2 2.32 0.535 0.0334 0.00836
500 m 9.29 0.581 0.134 0.00836 0.00209
1 km 2.32 0.145 0.0334 0.00209 0.000522
2 km 0.581 0.0363 0.00836 0.000522 0.000131
3 km 0.258 0.0161 0.00372 0.000232 0.000058
Energy reaching the target from a 250 W pulse laser in "watts"
Distance 0.03° 0.12° 0.25° 1° 2°
100 m 250 18.1 4.18 0.261 0.0653
250 m 46.4 2.90 0.669 0.0418 0.0104
500 m 11.6 0.726 0.167 0.0104 0.00261
1 km 2.90 0.181 0.0418 0.00261 0.000653
2 km 0.726 0.0454 0.0104 0.000653 0.000163
3 km 0.323 0.0202 0.00464 0.00029 0.000073
Energy reaching the target from a 1 kW pulse laser in "watts"
Distance 0.03° 0.12° 0.25° 1° 2°
100 m 1000 72.6 16.7 1.04 0.261
250 m 186 11.6 2.68 0.167 0.0418
500 m 46.4 2.90 0.669 0.0418 0.0104
1 km 11.6 0.726 0.167 0.0104 0.00261
2 km 2.90 0.181 0.0418 0.00261 0.000653
3 km 1.29 0.0806 0.0186 0.00116 0.00029
Energy reaching the target from a 2,5 kW pulse laser in "watts"
Distance 0.03° 0.12° 0.25° 1° 2°
100 m 2500 181 41.8 2.61 0.653
250 m 464 29.0 6.69 0.418 0.104
500 m 116 7.26 1.67 0.104 0.0261
1 km 29.0 1.81 0.418 0.0261 0.00653
2 km 7.26 0.454 0.104 0.00653 0.00163
3 km 3.23 0.202 0.0464 0.0029 0.00073
Energy reaching the target from a 5 kW pulse laser in "watts"
Distance 0.03° 0.12° 0.25° 1° 2°
100 m 5000 363 83.6 5.22 1.31
250 m 929 58.1 13.4 0.836 0.209
500 m 232 14.5 3.34 0.209 0.0522
1 km 58.1 3.63 0.836 0.0522 0.0131
2 km 14.5 0.907 0.209 0.0131 0.00326
3 km 6.45 0.403 0.0929 0.0058 0.00145
Energy reaching the target from a 10 kW pulse laser in "watts"
Distance 0.03° 0.12° 0.25° 1° 2°
100 m 10000 726 167 10.4 2.61
250 m 1860 116 26.8 1.67 0.418
500 m 464 29.0 6.69 0.418 0.104
1 km 116 7.26 1.67 0.104 0.0261
2 km 29.0 1.81 0.418 0.0261 0.00653
3 km 12.9 0.806 0.186 0.0116 0.0029
1 Like
4940

Is there an estimate for how much to blind the seeker?

4941

Not really, just some studies in which a PbS sensor was saturated (blinded) at ~6.1 W/cm² of sensor surface. The funny part about this value is: With the 2° beam opening the laser has ingame, even a 10 kW pulse at 100 meters would only hit the sensor with 2.61 W (over the whole chip, not per square-centimeter!). Most modern IIR missiles use InSb as the detector material.
Also it depends really much on how the seeker head of the missile is designed, if the laser is pulsed or CW, if there are taken precautions to register DIRCM and actively protect the sensor, if optical filters are used which only let a narrow optical band pass, what pulse lengths the DIRCM uses, etc.

1 Like
4942

Yes. All lasers have 2 deg.

4943

Lemme guess. They coded DIRCM emitter as an AESA radar and it jams whatever it can lock?

4944

New SLM max speed report
https://community.gaijin.net/issues/p/warthunder/i/3b4VvGZX2yZ8

8 Likes
4945

The fact that the IRIS-T won’t use your hard lock to self-adjust baffles me. Like, what is the radar even for?

4946

Emotional support

Jokes aside, theres an accepted bug report to have datalink as backup guidance all the way until impact, but its a year old and has yet to be fixed, pretty sure the devs just dont want helis to be balanced in any way or killable.
https://community.gaijin.net/issues/p/warthunder/i/blfh9aGDg3GQ

2 Likes
4947

Just to make sure: Gaijin doesn’t accept basic physical reasoning and demands a source for everything, right?
Otherwise the 2° beam opening of the laser would be reportable just going by the energy transmission rules…

1 Like
4948

Still waiting for the IRIS-T SLMs radar to get the back scan because currently it updates so incredibly slow

1 Like
4949

The most likely scenario is that it gets it with the broader radar rework, along the rest of the radars.

4950

Surely by the year 2090 we will have that

4 Likes