Jump to content

Su 27 Radar elavation scan


Recommended Posts

Hi guys, I have a question regarding slewing the Radar elavation scan range on the SU27 what confuses me, is the range estimation, if you don't know the range, what should you do? And a general explanation how you use it as an experienced pilot.

 

Thanks in advance,

Luza

[sIGPIC][/sIGPIC]

Link to post
Share on other sites

Well the best way is to 150 degree mode where you get the best results. Of-course it does take more time but at the same time does give you better results. Also if you are locked on from a distance you can move you nose a bit and will easily be able to know that the bandit is over you or below your altitude.

To support my models please donate to paypal ID: hp.2084@gmail.com

 

OR

Buy at

https://www.turbosquid.com/Search/Artists/hero2084

Link to post
Share on other sites

I am completely new to the SU 27 and russian aircraft, could you elaborate? What you just said makes me go ??

 

I have real trouble aquiring anything on my radar :S

 

Thanks in advance,

Luza

[sIGPIC][/sIGPIC]

Link to post
Share on other sites

You've actually made me think about how I use the radar now.

 

I have never once used the Range estimation, and have always left it at its default. I am wondering now what happens when I slew the radar scan zone up and down? Are the elevation increments creating gaps between the scanned areas at longer ranges?

 

Nate

Link to post
Share on other sites
You've actually made me think about how I use the radar now.

 

I have never once used the Range estimation, and have always left it at its default. I am wondering now what happens when I slew the radar scan zone up and down? Are the elevation increments creating gaps between the scanned areas at longer ranges?

 

Nate

In my humble opinion, yes. Watch the Marker on the right of the HUD as it travels up and down. Now. Turn down range to 2. Slew up and down, and watch the marker jump leaving big gaps. At range 10 there is overlap for example.

[sIGPIC][/sIGPIC]

Link to post
Share on other sites

Check this out

http://forums.eagle.ru/showthread.php?t=37440&highlight=Expected+range

 

Expected Range is the distance that you are moving the center of your radar up and down. Example1 Expected Range 20, Elevation +2 = Center of the radar 20km out is 2km above your current altitude. Example 2 Expected range 40, Elevation -1 = Center of the radar 40km out is 1km below your current altitude.

Edited by Crunch
Link to post
Share on other sites

This is my approach It makes some assumptions on radar beam widths in elevation gleaned from forum comments. In reality the MIG29 radar elevation beam witdth varies with range but this I don't think is modelled in FC so a constant value is used. I wrote this little burst for my self and a few mates I hope it helps, it works well for me. The Russian method is not as user friendly as the F15 Altitude coverage indications. The system is heavily biased to the pilot having accurate range and Altitude data by way of GCI and or AWACS. It is not set up well for a general Free hunt/Fighter sweep situation without GCI. However careful disciplined use it works quite well. This method is based on the traditional 1 in 60 rule.

 

MIG29/SU27/SU33 Radar Elevation coverage.

 

This assumes the Lockon FC2 Antenna elevation scan covers a total 7.65 degrees.

As measured in game (This is a 4 bar scan, Beam width is 2.0deg, there is some overlap)

 

Range Km Altitude covered Metres

10Km................1,338Metres

20Km................2,677Metres

30Km................4,016Metres

40Km................5,355Metres

50Km................6,694Metres

60Km................8,032Metres

70Km................9,372Metres

80Km................10,991Metres

90Km................12,050Metres

100Km ............ 13,389Metres

110Km .............14,728Metres

120Km .............16,067Metres

 

So Broad brush at 4000m Altitude if you set the expected Target range to 60Km and Delta H to 0 you should be covering Surface to 8,000m altitude. Remember this is 4 bar

So it takes some time (about 6 seconds) to cover the altitude block. At 30Km you cover

4,000metre block or from 2,000m to 8,000m in altitude.

 

Ruskierdr.jpg

 

 

General Radar search.

Initial system set up for general search. Radar range (HUD) set to 100Km. Set Delta H to 0. Set Expected Target range to 60Km. Position TDC at 0 azimuth at 60Km.

 

Since we are using 60Km as the base line and Delta H is at 1000m intervals it follows that for each 1000m Delta H adjustment you are tilting the antenna 1 degree (1in 60 rule). So if roaring around in the weeds there is little point irradiating the centre of the earth. Since the 4Bar scan is 7.65 degrees then all we need to do is tilt the scan up by 3.83 degrees. This will put the bottom of the scan at your level. So if in the weeds set 60Km and Delta H to +4

 

In general the same sort of thing can be used for minor adjustments of the scan if your altitude is > or < 4000m. So say for instance you are 6000m, if you want to cover the same 0-8000m block you would set the AH to -2. If at 3000m you would set Delta H to +1

 

Remember these are initial search settings. Once the action starts and target range starts reducing you will need to adjust Delta H to keep the target painting. As range reduces the scan volume reduces dramatically so antenna setting becomes super critical and requires quicker adjustment.

 

No matter what it is super important to be patient and consistent random slewing of the antenna elevation serves no purpose. As the paint starts to fade a single Delta H adjustment in the right direction will usually “freshen” the target paint. If it disappears it probably means you went the wrong way (or the target dramatically changed his altitude) so give it 2 Delta H clicks the other way.

 

Remember as soon as you take a lock Your Delta H and expected tgt range values are reset so when you return to search you need to re set the 60Km and Delta H value.

Edited by IvanK
Link to post
Share on other sites

I've no idea what 150deg mode is.

Could someone with alot of experience explain the su 27 radar in detail? The ingame tutorial is quite vague

What I do know is that the radar is displayed in the HUD of the Su-27,

 

Elevation angle scale,

is the scale to the right, it starts at 0 and goes up and down in increments of 1(eg. +1 or -1) to +15 or -15. These are increments of 1000's of metres, +3 = +3000m, set this for the targets expected altitude above or below you at the point of Range estimation.

 

Range estimation,

is the scale below the radar at the bottom, this is the targets expected range and defaults at 10km but can be adjusted from 1 to 150 km. Combine this with the Elevation angle scale to find your target.

You must remember that your radar always uses its max range, range and elevation estimations are just intercept and central points along the radars scan cone.

 

Range scale,

is to the top left of the radar, below your speed, it displays the max. range at which your radar screen displays (not scans) eg. 100 =100km at the top of the radar the bottom obviously being you.

 

Expected target aspect,

is directly beneath the range scale, it is the radars PRF (pulse rep. freq) mode. Select the correct mode which you believe will suit your target. There are 3 modes,

 

HI (ППС, in Russian HUD) for approaching tgts has the longest range

MED (ЗПС ) for running tgts has the shortest range

ILV (АВТ) default uses both HI and MED with a slight reduction in range than HI.

 

Below this still on the left are 4 symbols going down which don't always appear, the top is radar lock and is shown with a letter A (A in russian hud), 2nd down is EOS on which is shown by a letter T (T), 3rd one down signifies radar on and is shown as a letter I (и), 4th is for IFF and is displayed as an F ©, if lit you have a friendly locked.

 

 

Below this at the bottom left of the hud you have your radar mode, ther are three modes,

SCAN BVR, normal mode for all PRF modes

ATTACK BVR, STT mode when you have a target locked with full radar.

SCAN TWS, allows you to display a visual aspect in the MFD of multiple bandits but only avaliable with HI and MED - PRF modes.

 

 

 

 

When all displayed they will look like this:

 

500....................... 6000

100

ILV

 

 

A

T ................................... 0

I

F

 

 

 

SCAN BVR..... 10 ............

Edited by Frostie

"[51☭] FROSTIE" #55

51st PVO "BISONS"

Fastest MiG pilot in the world - TCR'10

https://100kiap.org

Link to post
Share on other sites

This is from the manual:

 

***************

IF YOUR FIGHTER IS AT AN ALTITUDE OF 5 KM AND AWACS REPORTS A TARGET AT RANGE 80 KM AND ALTITUDE 10 KM, YOU SHOULD TURN YOUR AIRCRAFT TOWARDS THE TARGET, THEN ENTER THE RANGE OF 80 KM AND RELATIVE ALTITUDE 5 KM INTO THE RADAR. THE RADAR SCAN ZONE WOULD THEN BE CORRECTLY AIMED AT THE EXPECTED TARGET ELEVATION.

*******************

 

So the distance (bottom of hud) is in Km from your aircraft and the elevation (right side of the hud) is in Km relative to your angels.

 

Again if you're flying 4 Km up and you expect the enemy to be 60 km out flying angels 8 you set the range to 60 and the elevation to 4(cuz you're 4 Km up so you just need 4 more to reach 8 Km). This setting should also pick up targets flying angels 12, 120 Km out, since the angle is the same. No messin around with degrees, just read the numbers..

 

Finaly: remember! -the distances in russian birds are in Km.

 

 

 

 

Cheers

Edited by Svend_Dellepude
Forgot something

[sIGPIC][/sIGPIC]

Win10 64, Asus Maximus VIII Formula, i5 6600K, Geforce 980 GTX Ti, 32 GB Ram, Samsung EVO SSD.

Link to post
Share on other sites
Guys I said to expand the radar scan zone to full and as it shows 150 on the HUD I said it just so that he might understand quickly.

Sorry friend but I believe this is bad practice, at 150 range when you elevate up your going up at 1000m 150km away for every +1 (a very small elevation). You'd need to move all the way upto +15 just to see a bandit something like 30km away 3000m above your altitude.

 

A good standard to use is at the 20 to 30 range.

"[51☭] FROSTIE" #55

51st PVO "BISONS"

Fastest MiG pilot in the world - TCR'10

https://100kiap.org

Link to post
Share on other sites
In my humble opinion, yes. Watch the Marker on the right of the HUD as it travels up and down. Now. Turn down range to 2. Slew up and down, and watch the marker jump leaving big gaps. At range 10 there is overlap for example.

 

Range 10 is the default IIRC, I'd agree with your analysis but I'd like to see it confirmed.

 

Can I scan all off the sky in front of me, without gaps, by slewing, in the extreme example, -15 to +15 on the elevation with the range set to 10?

 

Does each increment overlap at all ranges, when the range is set to 10? Again I suspect they do, but I'd like it confirmed.

 

Nate

Link to post
Share on other sites

Could well be 10 degrees. If that is the case it provides a little more overlap/coverage to the method.

 

The real curse of the Russian system (when used without GCI) is that 1 click of tilt doesn't always result in the same angular displacement of the antenna. As you vary the expected target range the angular value per click also changes to fit the expected target range Delta H setup ! This is the reason you need to use a constant Expected Target range value so you have a firm datum to search the entire scan area ahead of you. Then you know that 1 click up or down will cover XX block of airspace at YY range and you wont leave any gaps.

 

Here it is reworked on 10degrees total angular coverage.

 

MIG29/SU27/SU33 Radar Elevation coverage.

 

 

This assumes the Lockon FC2 Antenna elevation scan covers a total 10 degrees.

(This is a 4 bar scan, Beam width is 2.5deg, there is some overlap sidelobes ? :)

 

 

Range Km Altitude covered Metres

10Km............... 1,749Metres

20Km .............. 3,499Metres

30Km .............. 5,249Metres

40Km............... 6,999Metres

50Km .............. 8,748Metres

60Km............... 10,498Metres

70Km............... 12,248Metres

80Km .............. 13,998Metres

90Km .............. 15,747Metres

100Km ............ 17,497Metres

110Km ............ 19,247Metres

120Km ............ 20,997Metres

 

 

So Broad brush at 5000m Altitude if you set the expected Target range to 60Km and Delta H to 0 you should be covering Surface to 10,498m altitude. Remember this is 4 bar

So it takes some time (about 6 seconds) to cover the altitude block. At 30Km you cover

5,249metre block or from 2375m to 7625m in altitude.

 

rdr10kcvr.jpg

 

 

 

General Radar search.

Initial system set up for general search. Radar range (HUD) set to 100Km. Set Delta H to 0. Set Expected Target range to 60Km. Position TDC at 0 azimuth at 60Km.

 

Since we are using 60Km expected target range as the base line and Delta H is at 1000m intervals it follows that for each 1000m Delta H adjustment you are tilting the antenna 1 degree (1in 60 rule). So if roaring around in the weeds there is little point irradiating the centre of the earth. Since the 4Bar scan is 10 degrees then all we need to do is tilt the scan up by 5 degrees. This will put the bottom of the scan at your level. So if in the weeds set 60Km expected target range and Delta H to +5

 

In general the same sort of thing can be used for minor adjustments of the scan if your altitude is > or < 5000m. So say for instance you are 6000m, if you want to cover the same 0-10,000m block you would set the AH to -1. If at 3000m you would set Delta H to +2

 

Remember these are initial search settings. Once the action starts and target range starts reducing you will need to adjust Delta H to keep the target painting. As range reduces the scan volume reduces dramatically so antenna setting becomes super critical and requires quicker adjustment.

 

No matter what it is super important to be patient and consistent, random desperate slewing of the antenna elevation serves no purpose. As the paint starts to fade a single Delta H adjustment in the right direction will usually “freshen” the target paint. If it disappears it probably means you went the wrong way (or the target dramatically changed his altitude) so give it 2 Delta H clicks the other way.

 

Remember as soon as you take a lock Your Delta H and expected tgt range values are reset so when you return to search you need to re set the 60Km expected target range and Delta H value.

 

With respect to Azimuth scan don't forget with the Russian radars you can offset the whole Scan Left, Centre and Right. For a serious scan and to cover the full left to full right you need to scan the entire elevation volume in each Azimuth scan. Again it requires a strict practised routine to ensure no gaps and it requires time. If flying with a Wingman then some co ordination can be used with each guy responsible for a specific bit of airspace both in Azimuth and elevation...... but that and sorting is a Volume in itself.

 

TIP

Unless under GCI/AWACS control ALWAYS set Expected Target range to 60Km.

Edited by IvanK
Link to post
Share on other sites

Hey guys's ty for answering my question, I have another.

When target is straight ahead of me, and locked, no where near out of my antenna range, why do I randomly lose targets when I have them locked?

 

Thanks in advance,

Luza

[sIGPIC][/sIGPIC]

Link to post
Share on other sites

There's nothing random about it ... your target is doing something to make you lose it.

[sIGPIC][/sIGPIC]

Reminder: SAM = Speed Bump :D

I used to play flight sims like you, but then I took a slammer to the knee - Yoda

Link to post
Share on other sites

Easiest way I find to break a lock is to beam the opposing radar (3 or 9 o'clock position) and bank wings at 30 - 45 degrees. I find that it always breaks the locks, but you require alot of rudder input to remain level when doing this.

See, decide, attack, reverse -- Colonel Erich "Bubi" Hartmann

 

i7 7700k, MSI z270 M3 mobo, 16 Gb Ripjaw DDR4 RAM, Gigabyte Aorus GTX 1080 Ti, Corsair H100i V2 liquid cooler, Corsair NVMe SSD for OS, 1tb Mushkin SSD for games, Warthog HOTAS, Saitek Rudder Pedals, 5.1 surround, Oculus Rift

Link to post
Share on other sites

@IvanK wouldn't it be wiser to keep the expected range lower than 60km so that you can cover higher altitude with lower "bars" (elevation adjustments), for example setting it to 20-30km and doing a 3 bar scan is going to cover complete spectrum of altitude a bandit may be flying at (12km+ alt is not covered by your proposed 4 bar @ 60km expected)

 

@luza what GG and Spetz are referring to is called notching the bandit's radar. This is done by decreasing relative closure rate and introducing ground clutter so that the enemy's radar will have a hard time fighting the doppler effect and having to sort through the clutter. If you search the forums more you will find better explanations for this elsewhere.

Edited by Sov13t
Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...