stealthflankerRIP. What an unfortunate event.
stealthflankerRadar Horizon. You will not get 1000km range unless the aircraft is flying outerspace or in extremely high altitude.
The calculator has not taking factor of path propagation (The F^4) in the calculation. Which could be ideal for airborne situation but not ground. There are also STC (Sensitivity Time Control) and possible MTI employment which will limit the detection range (esp minimum) even further. This is not implemented yet as it basically making a whole new calculator as MTI and STC is range dependent and calculation must be performed iteratively.
stealthflankerIm curious if there is any news regarding the new R-37 and the Kh-59MK2.
stealthflanker@Mig31bm.
Well if it’s 2.5 GHz then using it as IFF is kinda suspect as both Russia and US use L-band for IFF purpose, and having S-band, despite having better gain doesn’t seem to have its merit in detecting low RCS target. Regarding Multipath height finding, you can read it here
http://www.radartutorial.eu/01.basics/rb63.en.html
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Regarding the AESA calculator, im still workin on it… hmm finding better and more relevant/correct method to calculate. Current plan is to add ECM. The ECM being added is Noise jammer and Cross Eye jamming.
The noise jammer will provide calculations of Burn through range, while the cross eye will calculate possible error generated by the jamming. Counter-Countermeasure for cross eye however im afraid can’t be really taken into factor because :
1.Limitations of excel, can’t really do complex integrals.
2.There are no real literature published regarding cross eye counter-countermeasure. According to Introduction to Airborne Radar by Stimson. The method relevant to counter cross eye is currently classified. However let’s see what i could find.
stealthflankerWell, what respect you want to compare from them Garry ? you might want to limit it to some factors.. say cost per flight hour or generic price, then discussion could be start in hopefully proper manner.
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Paralay did good one there in quantifying, and unless someone come up with equivalent work, it would be unfair and disrespectful to dismiss his without considering the amount of effort to make that tabulations.
Some more elaborations however would be needed on why it calculated that way.
stealthflankerKinda huge overkill tho for Tochkas. The job could be adequately done by Buk. but well whatever floats their boat.
stealthflankergenerally passive system will have longer detection range than active system (radar, etc) due to favorable physics. Higher altitude will help the system to see farther.
However. Range will be affected by the sensitivity of the system too. and sensitivity itself a function of computational power. High altitude might offer longer range BUT it also expose the sensor to heavy pulse traffic which need to be processed, and not including possible natural or man made noise. This will limit the usable sensitivity and later interception range, classification and geolocating ability.
J.Lynch’s book “Introduction to RF stealth” offers analysis method for ELINT/ESM system and how to quantify performance. It’s pretty math heavy tho so i haven’t tried alot of methods described there.
stealthflankerYeah my mistake 2.5 m should be the width of the antenna not area.
stealthflankerVery insightful, thanks.
I have some general questions:
– How applicable is the use of the spreadsheet for PESA? Can we take the peakpower, divide it by amount of phaseshifters and put it in a T/R modules? Would the result be representative or are there some effects for AESA that are considered and hence this would deliver false results?
– How would the parameters of a hypothetical AESA 92N6 S-400 engagement radar look like? Since just a single array is used, we can exclude a continuous wave operation (although many sources for some reason state that the SA-6 with its single engagement antenna is a CW system)? So how would the parameters (PRF, pulsewidth) for a pulsed illumination look like approximately?
– A general question on AESAs for illumination role I always had is, whether a part of the array could use transmit-only elements with higher peak power per element, and the other part normal T/R modules. I see much higher power levels for transmit-only modules which may could compensate the lower number of receive-capable modules. Even if there would be no benefit for the range performance due to the lower receive modules; in SARH (bi-static) operation, the missile seeker would receive higher RF energy.
1. I will not recommend it for PESA. As it need to be treated differently. Especially for the space feed array. Russian research on Space feed array appears to be ahead of US. To the point where they can realize advanced feed with low sidelobe. As described below :
https://www.scribd.com/document/275319467/Recent-Developments-in-Russian-Radar-Systems
Some technical informations regarding the design of array in S-300 and S-300V
https://www.scribd.com/document/289047418/Survey-of-Russian-Low-Cost-Phased-Array
2.Hypothetical AESA for 92N6 would be massive. 2.5 sqm array of 92N6 will contain about 12000 TRM assuming it wish to retain same beamwidth as original 30N6/92N6. The maximum attainable peak transmit power with current state of the art technology (1.5 Watt/mm for GaAs) would be 22 Watt multiply it with 12000 it would be 264 Kilowatt for peak transmit power using GaAs. GaN would be even more powerful with 7 Watt/mm power density. X-band module with half wavelength width would attain 105 watt. and the transmit power would be 1.26 MW for 12000 elements. Range figure with GaN would roughly be about 68% higher than GaAs.
The 5N63 family and her siblings, 30N6 and 92N6 is a pulse doppler design with 100 KHz of PRF. The pulsewidth would be around 1-2 microseconds. There is no info though on how much pulse compression factor involved. Unfortunately so if you desire to calculate, you will have to consult on the table of waveform i provided. In previous page. There also be another factor which i haven’t implemented in the sheet which is F4 or Pattern propagation Factor. This would affect ground based radar more than the one airborne. The design duty cycle however could be assumed to be 25% maximum for avoiding/reducing eclipsing issues.
Regarding Illumination role. Some AESA’s do behave similar way as you describe, which is SMART-L where some elements with wide beamwidth will “flood” the area with radar energy while the receive party scans the skies for target return. However it’s the transmit module that are less in number than receive as transmit does not need such large beamwidth. Receive module would be more in numbers due to need for narrow beamwidth resolution.
Does that formula take into account elements spacing?. Elements seem very close together, your example wavelength is 24 cm, 24/2= 12, i doubt that woman wrist can be 12 cm wide. Even 6 cm wide wrist seem very rare
Yes, my formulas automatically assume that it’s a half wavelength spacing. If there is any less like in the image, the only explanation would be that the array isn’t exactly 1250 Mhz but rather lower wavelength. It could operate in 1250 Mhz but with limited scanning angle. Otherwise it might not be in L-band at all but something higher maybe S or C band.
Guys.. i hope you don’T mean to debate the L-band IFF transmitter as a magical Russian AESA.
Well given the controversial nature of the device, one or two debates would occur sooner or later. and naturally i am also interested to see its potential as real Primary radar. The reason is similar as given by Carlo Kopp. Why putting the antenna there ?.
Traditionally IFF is always in L-band. Implementation however usually embedded together with main nose array Thus the radar can interrogate while also doing scanning. If it placed anywhere else, naturally one would question why. I would love to see other people brewing their own calculations too.
I really not bought into theory “the beamwidth is too wide” etc as the radar have narrow beamwidth just for 1 side (horizontal) and that’s about enough for scanning. The elevation beamwidth is indeed very broad But, treatment with dielectric lens can mitigate it into somewhat acceptable (still wide tho 20-80 degrees) Heightfinding cannot be done in the way usual radar does BUT can use the same way as how E-2 determine altitude via multipath heightfinding.
E-2 Hawkeye’s radar antenna is also a linear array consist of several YAGI elements. The differences is that it scans mechanically while this NIIP array scans electronically. The APY-9 for new E-2D would scan electronically and conceptually similar as one in NIIP.
stealthflankerSo. anyone have any idea where is the S-300V4 supposedly deployed to Tartus ? Tried finding it in Terraserver but i can’t find any sign of deployment or news.
stealthflankerThe vertical length of the search sector might be irrelevant. But, radar beamwidth still have 2 dimensional nature, thus you can’t simply discard it as the target may arrive at the vertical part of the beamwidth. Therefore the squared value
stealthflankerWell the beamwidth is squared to take account of its cross sectional area. The number of beam positions equation basically states the area of the search sector divided by the cross sectional area of the beamwidth.
So you can’t just divide the horizontal sector with beamwidth and later multiply it with dwell time to get scanning time.
stealthflankerWell have you looked at the equation i posted ? It’s not simply like that. The beamwidth is squared.
The mistake i did however is that i still included the vertical scan part which i fixed immediately. Now you got only 57 seconds instead of 5 minutes.
stealthflankerhmm even Ka-52 can carry them
[ATTACH=CONFIG]255958[/ATTACH]
and this
[ATTACH=CONFIG]255959[/ATTACH]
I’m curious if KA-52 ever have chance to fire Kh-35.
stealthflankerAnd now a quick fix for the Linear array. Since the Beam only scan in azimuth. The equation for scanning time/time frame must be adjusted that it no longer include the vertical scan for the radar.
Download Link
https://www.mediafire.com/file/7wrkyslc1p4d36r/AESACalcTrial.xlsx
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Furthermore regarding the addition of clutter and possible ECM. I would work on brand new calculator, and includes method to calculate SIR (Signal to Interference Ratio) and others like SCR (Signal to Clutter Ratio). The main problem with this is that there are no real closed form solution for calculating range. E.g the calculation would be done in iterative manner. The equation would include range as variable and the result would be Detectability factor (Dx) Which later be compared with required detectability factor.
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