APQ-50/72/100/109/120 detection range?

lancer21

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Hello everyone , new user , happy to be here! Great site , been following it for quite a while, and decided to join, so much interesting info and discussions here!

Now, as my topic title suggests , i'd like to ask if someone has some datas on these radars, at least some summary data on their detection range against fighter and bomber RCS targets ? Surprisingly, even if the F-4 is an old bird, cant find much reliable info on its various radars, tried few places , but no luck so far.

Also , if i understand correctly , none of the above radars have LD/SD capability , except the AWG-10/11/12 sets, right ?( and if anyone have dats on their characteristics too , i'd be grateful)

Thank you for your help!
 

lancer21

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Well after alot of browsing , i did found a good old harpoon PDF document containing various radar data ...its not 100% accurate , but thats all i got , i read there that the APQ-120 is credited with a max detection range of 50nm, and the APQ-100/109 with 40nm...i'll just post what i got, harpoon gives the range for various size target ( large, medium , small , v. small in that order )

APQ-120 AI 50/35/26/11/3
APQ-100 AI 40/25/19/8/2
APQ-109 same

...is anyone able to confirm these datas please? Thank you.

BTW extermely surprising that harpoon credits Cyrano-IVM with JUST 30nm !!! but thats another issue...
 

Pit

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Document for game playing, not real time performance :D
 

lancer21

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I know but thats all i could find on the bloody things! :D

( save for something from our good russian friends comunity ...but even there the information is contradictory ...so its still open )
 

PG_69

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APQ-72 given as 56 km vs MiG-17 and 25-30 miles vs BQM-34 drone.
 

lancer21

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Interesting info , thanks. :)
Would you have a source for this info please?


I have been looking around on various russian boards for info on these radars , i found some unconfirmed fugures for the APQ-120 , for instance detection range for a 1m2 RCS target being 56km!( 30 nm-incidentaly this info is published in VERY old Flight Global magazines , at the end of seventies...). Other infos state the detection range for a FIGHTER size target is 70km , while still other info states that this 70km figure refers to a BOMBER size target detection range ...

Gee what is so secret about this radar that one cant find any reliable info around ... ???
 

overscan (PaulMM)

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1) targets vary in RCS at different angles

2) detection range varies in different conditions

3) detection of targets is not 100% reliable.

4) performance of analogue radars depends on how well they are tuned and maintained.

Its not like the target is at 90.1km away and you definitely can't detect it, but then next sweep its at 89.9km and you can detect it with 100% certainty. Radar X might have 10% chance of detection for a given size target at 90km, 50% chance of detection at 70km, 90% chance of detection at 50km. If you wanted, you could claim it has a range of anywhere between 50km and 90km - do you go with the maximum possible range, the average range, or the range where you can be almost certain to detect the target?

Westinghouse brochures for the APG-66 quoted range for a 90% chance of detection, but when the figures were repeated elsewhere, most writers used only the range value. If a rival company wanted their radar to appear superior, they could quote the range for 50% chance of detection, or quote the maximum range ever seen during testing, and seem to have a longer range radar, but it might not be really any better.

So finding a single agreed range figure is a fruitless task....
 

lancer21

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Thanks for your reply Overscan , yes you do have a point offcourse. As i mentioned before in another topic i dont know much about the technical stuff ( klystron tubes ,waveguides and the likes) , but i'm just an enthusiast( fanboy? ) who likes to learn and know things about ones hobby...

Lets just say i'm just looking for the sort of info on detection ranges for APQ-120 and other Phantom radars, like you have ( had ?) on your russian avionics site for various russian radars, from a decently reliable source ... :)

Thanks again.
 

crossiathh

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Conical Scan or Monopuls

APQ-50/72/100/109/120

Do they still using conical scan or are these monopuls radars?
 

lancer21

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Hehe, after a year i got into the "Phantom radars" fever again. ;D

It's late, but may i ask , is the above reply ment to me or the poster above ( i did go thru the AWG-10 topic , although in all honesty i don't understand 90% of the technical stuff posted there. :-[ Off course i did found the 60nm vs 5 sqm RCS target range figure, quite impressive for those years i guess).
 

Blaze1

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overscan said:
Its not like the target is at 90.1km away and you definitely can't detect it, but then next sweep its at 89.9km and you can detect it with 100% certainty. Radar X might have 10% chance of detection for a given size target at 90km, 50% chance of detection at 70km, 90% chance of detection at 50km. If you wanted, you could claim it has a range of anywhere between 50km and 90km - do you go with the maximum possible range, the average range, or the range where you can be almost certain to detect the target?

Westinghouse brochures for the APG-66 quoted range for a 90% chance of detection, but when the figures were repeated elsewhere, most writers used only the range value. If a rival company wanted their radar to appear superior, they could quote the range for 50% chance of detection, or quote the maximum range ever seen during testing, and seem to have a longer range radar, but it might not be really any better.

So finding a single agreed range figure is a fruitless task....
overscan, when you talk about the probability of detection, is this based on a single sweep?

Thanks
 

pjforus

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Detection limits, A/N APQ-109:

A/A search/aquisition B-sweep: 40 nm (if memory serves)
A/G PPI-sweep: 200 nm

I suppose the reason for the short A/A range is the low power/high prf rate upon target lockon. With the old conical scan sets, the high prf and short pulse of the locked-on mode allowed accurate angle, range and range rate tracking.

Regarding LD/SD, the set could certainly look down, but missile firing solutions for old-school AIM 7's & AIM 9's calculated by the A/N APA-165 system didn't allow much angle deviation. Regarding A/G missiles and smart bombs, the F4 C/D platforms were pretty robust, and allowed for many mods to accommodate a wide variety of fire control modalities which integrated with the A/N APQ-109.

I guess this has been de-classified by now...right?
 

Phantom tech

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I was a radar technician stationed in Thailand during the Vietnam war. I was testing out operation of a system on the flight line, something I didn't have very many opportunities to do. Using the B sweep mode set for a hundred miles range I picked up a Target about 70 miles out which I can only assume from its size was a B52. I locked on and tracked him approximately 2 to 3 minutes before I was jammed by electronic countermeasures.
 

Flame2512

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Here are some extracts from the F-4E plus contract summary (credit Ron Downey via Aviation Archives): http://aviationarchives.blogspot.com/2016/01/f-4e-plus-contract-proposal-summary.html

It lists the performance McDonnell Douglas was willing to guarantee for the AN/APQ-120 radar system. This is obviously from before the F-4E entered service, so it is unclear how the radar actually performed against these guarantees, but I thought I would share it as it's the first official(ish) numbers I've stumbled across for AN/APQ-120 performance.

The contract proposal also mentions the Coherent On Receive Doppler System (CORDS), which was meant to provide look-down capability for the F-4E. In practice they could never get CORDS to work reliably so development of it got scrapped 1968.
 

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lancer21

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I have found some good info in a declassified pdf about the Have Doughnut MiG-21 testing. Real world average detection range for APQ-109/120 head on vs MiG-21 is 20nm aquisition and 15nm tracking, from tail-on is 25/17, and from abeam is 35/28.

Edit: According to the report, APQ-109 has a 5-10% range detection/tracking advantage re the APQ-120 (so annoyingly for me they haven't listed separate figures for 109/120, just averaged the figures as shown above)

There is also info for APQ-72 and APG-59, but have to study those chapters later (i'm way late into the night perusing that report)
 
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lancer21

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I've edited above with some additional info.

Figures for APQ-72 are:

At low to medium 5000- 15000ft altitude, detection at max 32nm, average 20-25nm. Tracking at max 18nm, average 15nm.
At medium to high 15000-30000ft altitude, detection at max 40nm, average 30-35nm. Tracking at max 27nm, average 25nm.

For APG-59, in pulse mode figures (not mentioned) were slightly less compared to APQ-72, the latter was a bit better at high alt, while the former a bit better at low alt.
APG-59 in pulse-Doppler mode, front quarter average detection in excess of 45nm, with a maximum of 62nm. Couple of tests resulted in the MiG being detected, aquired and tracked at 50nm and 15,000ft.
 

lancer21

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Having found out these very interesting figures, i'm wondering now if there's any info as to the weight of these radars? I've read somewhere that the APQ-120 weighs 290kg (approx 640lb), while in the AWG-10 topic it says that radar weighs between 650 and 750lb (340kg), not sure why the weight difference.

Really, the reason i'm trying to find this kind of info is that i want to find out how contemporary american and soviet radars compare ( i'm not knowledgeable into the deep technicals of it, so the basic numbers like range weight etc have to do for me), i'm trying to compare apples to apples as much as possible. Very interesting the 3 different detection range aspects for the APQ-109/120, namely head-on, tail-on and beam-on, each showing successively longer ranges.

Perhaps diverting a bit too much here, but does anyone know if the pretty well known russian radar ranges figures (for radars like S-23, Oryol, Smerch etc) refer to head on aspect and are they average figures, in which case should it be assumed that tail-on or beam-on figures should be roughly increased as for the APQ-109/120, and same for maximum possible ranges?
 
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