AESA Radar range calculator.

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[USER="70376"]stealthflanker[/USER]
Thank you, i will check it out, your is the most detail calculator we can find on the public sector
P/s: with all due respect, i think there is something seriously wrong with the multipath model, I tested the calculator with several RCS values and found that
1) The detection range is far shorter vs a target with RCS = 12 m2 than a target with RCS =10m2

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And target with RCS = 0.4 m2 is detected at much shorter distance than target with RCS =0.001 m2
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It is because the F4 (path propagation factor) is a function of range-altitude.
As you see The path propagation factor is not linear, which reflect the environment where reflection from radar may travel different path and interact in various manner. As indication you may see the "Target Effective RCS" Which the target RCS is corrected with the calculated path propagation factor. That is what your radar actually see instead of academic "free space" RCS which you inputted. Thus an object with RCS of 12 Sqm at some point can look alike it's 0.01 sqm thanks to the local path propagation factor.

I think i got your point, so at some point, a target with RCS of 12 m2 can look like it is 0.001m2 thanks to destructive interference from path propagation factor , yet, on the other hand a target with rcs of 1 m2 may not benefit from that, since its reflection is too weak to abuse the scattering/reflecting effect of the surface?

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Forgot to tell you all that the model presented here was more or less validated by the "dad" of RBE2AESA. Greetings!

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Yes. You can also plot the target RCS fluctuations the same way and yielded with following plot. The "free space" target RCS is 0.1 sqm. As you see it fluctuates from very small value (but not zero) to 1.6 sqm. It could explain why it's hard to detect and maintain proper contact with low flying target and the reason why Israel use of Delilah Cruise missiles were of high effectiveness.
Alright if that is the case, i think there are 2 issues: 1) The detection range should be displayed with a chart instead of a single number , because if i understand correctly, your model will show the radar detect something, then totally lost it , then detect it again, then lost it again, and so on, we will have something like a "skip area" and "anti low VLO area" 2) If the target's free space RCS affects the path propargation the way i described above, then clearly the amount of "reflection" which comming toward the ground surface matter which mean the shape of the object matter, because 2 objects can have the same RCS, yet have different distribution of radar scattering sector, to put it simple, one object can reflect 60% radar wave toward the sky and 40% toward the surface, while another with the same RCS can reflect 20% radar wave toward the sky and 80% toward the surface.

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To make it easier to understand, imagine for example, if your radar looking at an aircraft at the same altitude as you, the free space RCS is a fixed number, if you flipped that aircraft upside down, the free space RCS is the same, but the path propagation RCS should change, this can't be intergrated in the current model i think, i guess it might be too complex for us to use excel

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[USER="71228"]garryA[/USER] Thanks for the suggestions. The thing is that it would make the calculator more difficult to use. The basic equations will also change closer to the one in K.Barton's book which may require user to actually input designated range for plotting. For most generic use the single value is adequate.

And regarding the path propagation model, it assume point target, so the target is assumed to be pointlike (basically having same RCS in all sides)

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Yes. You can also plot the target RCS fluctuations the same way and yielded with following plot.</p> <p>The "free space" target RCS is 0.1 sqm. As you see it fluctuates from very small value (but not zero) to 1.6 sqm.</p> <p>It could explain why it's hard to detect and maintain proper contact with low flying target and the reason why Israel use of Delilah Cruise missiles were of high effectiveness.</p> <p>[IMG]https://forum.keypublishing.com/filedata/fetch?photoid=3847948&type=thumb[/IMG]<br /> [URL="https://forum.keypublishing.com/album/145305-aesa-radar-range-calculator"]1 Photo[/URL]

11 kms heigh of the antenna....you are talking about a Awacs antenna?

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yes [USER="76365"]RALL[/USER] I'm using AEW as example for the graph.

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yes [USER="76365"]RALL[/USER] I'm using AEW as example for the graph.

Thanks.

I am reading last page and i am litle confuse about sometimes is is possible have better rcs in L band than X band....really i thought always will be worst rcs for stelth fighters in L or UHF bands. Of course bombers as B-2 is different.

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Not really an update. but as part of development i added a "result sheet" where one can review its radar specifications, and it has a graphical comparison with some known radars.

The idea is to create a "standarized" sheet one can simply block, copy-paste to paint then put it online or elsewhere to show its Radar.

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Since this calculator is basically for fighter aircraft radar. It is of course at the moment the available comparison "database" would be based on fighter radars too. All values of the comparison database has been "mercilessly" normalized to R90 or Detection range where the probability of target detection is 90%. So don't freak out on why Irbis-E only have 223 Km of range vs 3m sqm. I assume the 350-400 Km range is 50% detection probability. Same goes for other radars.

In the future i would try working a way that can compare the radar in more "reasonable" value. As its clear that one cannot really compare AEW Radar with Fighter radar nor comparing X-band to VHF band at least directly. The system i am thinking of is to use Frequency as means of comparison. So when you input say X-band the sheet will display X-band Radars and maybe up to C-band. if you input S-Band it will display comparable radar system that works in similar band and so on. If one wish to compare S-band with VHF. Then i need to think a way to make a representative conversion factor for RCS.

As the calculator develops i might also try incorporating some signal processing element, and yes better multipath plus clutter. It will however have weaknesses and may rely on deep approximation and simplification of cases. However it should be good to know if say Pulse doppler is better than MTI in certain situation or vice versa. The main output of the process if i could implement it would be Improvement factor in dB which can later be used along with plot of SCR (Signal to Clutter Ratio) to determine if the processing managed to clear the clutter or not. The range however can no longer be directly computed. It has to be plotted and then range is found through skimming the graph when the signal energy exceeds clutter energy.

The sheet however will first compute free space range, then using that range as the "edge" of the plot and baseline for signal processing calculation.

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[USER="71228"]garryA[/USER]

The only downside of the path propagation factor model that i used is that it's assume flat smooth earth. Which could be representative for sea than land. However The model works just as fine and yes it will show non-linear result and yes it might be surprising given how non-linear it is. It is because the F4 (path propagation factor) is a function of range-altitude. If we plot path propagation factor for your altitude value, we will have the following graph.

As you see The path propagation factor is not linear, which reflect the environment where reflection from radar may travel different path and interact in various manner. As indication you may see the "Target Effective RCS" Which the target RCS is corrected with the calculated path propagation factor. That is what your radar actually see instead of academic "free space" RCS which you inputted. Thus an object with RCS of 12 Sqm at some point can look alike it's 0.01 sqm thanks to the local path propagation factor. If you follow my previous post addressing your concern regarding RCS value in VHF. You will find i also address path propagation factor there, which explain why different detection range just based on antenna height.

As for calculation method, given that the F4 factor is not linear. I am using the suggested method by "Handbook of Simulation in Radio engineering, Communications and Radar" by S.A Leonov and A.I Leonov.
In the book the way to calculate the radar range in presence of environment factor is to first calculate the "free space range" or "radar range in Vacuum" Then use the range value from there to compute the Path propagation factor and then re-use it for the refined calculation of the radar range.

But propagation path is changing in very moment, because geography change. How is possible to take a propagation path factor for all enviroments? each enviroment is diferent, so each enviroment have a unique propagaqtion path factor...is it not?

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But propagation path is changing in very moment, because geography change. How is possible to take a propagation path factor for all enviroments? each enviroment is diferent, so each enviroment have a unique propagaqtion path factor...is it not?

It is. Sea, ground have different electrical properties including the presence of vegetation and this have effects on propagation.

Exact solution however is not available. But approximate and estimates are available, which i am thinking to implement. You can see methods and calculations involved in determining path propagation factor in "Handbook of Computer Simulation, in Radio Engineering, Radar and Communications"

The main weaknesses in the method however is that it assumes uniform distribution of the environment. e.g "jungle all the way" There is no real method yet as far as i know that allows for multiple environment (say 100 km of sea then 10 Km land to radar station).

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Thanks stealthflanker. I understand it..

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[USER="70376"]stealthflanker[/USER]
are these formula incorrect?

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[USER="70376"]stealthflanker[/USER]
are these formula incorrect?

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Should be correct. although i wonder why it has different arrangement to the one in the possible source material, David Adamy's EW-101 book. This is the equation look like in the book.

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Should be correct. although i wonder why it has different arrangement to the one in the possible source material, David Adamy's EW-101 book. This is the equation look like in the book.

I don't understand their final formula, what is Rt and R? how did they get rid of RCS, ERP in their final formula?

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Following their result, seft protect jamming is extremely effective?, any aircraft can get the fight to visual range with a jamming pod?
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Do you think F-16 with ALQ-184 is adequate to get the tracking range of Zaslon-AM or IRBIS-E to visual range?

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I don't understand their final formula, what is Rt and R? how did they get rid of RCS, ERP in their final formula?

They should be the range to target from the radar and R one is range of jammer to radar. and it is NOT the final equation. The last term is the instruction that to get the result in the unit of distance, you have to use the base 20 anti logarithm to convert the result of previous equation from Decibel value back to the unit of distance (miles, NMI, km etc)


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Following their result, seft protect jamming is extremely effective?, any aircraft can get the fight to visual range with a jamming pod?
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Do you think F-16 with ALQ-184 is adequate to get the tracking range of Zaslon-AM or IRBIS-E to visual range?

an important note is that concept of "burn through" range does not apply to self protection jammer as it use different technique to get their job done. Burn through range only applicable to noise jamming situation. The equation may provide answer BUT that does not indicate the radar cant do anything on the presence of self protection jammer.

To quantify the effect of the self protection jamming, one have to know the radar's ECCM's capability and availability of certain counter-countermeasure mode. Say ALQ-184 may have repeater mode and "double" RGPO & VGPO modes. If Irbis or Zaslon have say, "VGPO-RGPO Reset" or can quickly re-acquire target after the jammer "cuts down" the acquisition process. Then it can quickly reestablish track on the F-16 and engage.

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an important note is that concept of "burn through" range does not apply to self protection jammer as it use different technique to get their job done. Burn through range only applicable to noise jamming situation. The equation may provide answer BUT that does not indicate the radar cant do anything on the presence of self protection jammer.
To quantify the effect of the self protection jamming, one have to know the radar's ECCM's capability and availability of certain counter-countermeasure mode. Say ALQ-184 may have repeater mode and "double" RGPO & VGPO modes. If Irbis or Zaslon have say, "VGPO-RGPO Reset" or can quickly re-acquire target after the jammer "cuts down" the acquisition process. Then it can quickly reestablish track on the F-16 and engage.

What if the ECM pod uses noise jamming? i remember that mode is available on ALQ-184 and ALQ-131 pod?
What if there is a MALD-J nearby and it use noise jamming to protect F-16? what is the option to break through the noise jamming?
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What if the ECM pod uses noise jamming? i remember that mode is available on ALQ-184 and ALQ-131 pod?
What if there is a MALD-J nearby and it use noise jamming to protect F-16? what is the option to break through the noise jamming?
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Then it can be burned through as standoff jamming. Except this time the jammer is co-located.

The Multiple number of noise jamming can be countered through processing. like say generation of jammer strobes, with hope that some targets is not covered.

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Other countermeasures are available in this list :

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Otherwise is to engage the jammer, which is why we have trend of increasing munitions quantity in today's ground based SAM's

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Then it can be burned through as standoff jamming.

I got it, but what distance do you expect/estimate IRBIS-E/ZASLON to burn through MALD-J jamming, if the target being protected is an F-16?, is the noise jamming enough to get it to visual range?