Snappy Posted January 16 Posted January 16 Hi, I have some questions regarding the two different modes of setting radar elevation. The manual explanation I find kind of difficult to understand. 1. So contrary to some info floating around the internet and contrary to even chucks guide , the digital differential readout to the lower left of the radar screen always shows altitude differential and never actual antenna degrees, even in E mode ? Its confusing because the official manual says about it "2 digits : always indicating the difference in altitude." 2. Do I understand it correctly that the main difference between the D and E modes is, that in D mode, the altitude differential readout set/ shown is valid for the current alidade position, no matter where the alidade is on the radar screen? I.e. if I park the the alidade 20nm straight ahead and set the differential to +15 in D mode, the radar will scan the airspace 20nm ahead of the Mirage 15000ft above my own aircraft? is this correct? 3.) In E mode, I have to set the alidade to 10nm and the readout will then display what? altitude difference or antenna elevation in degrees? What exactly does the E mode readout show when I set the aldidade to 20NM and then adjust the elevation to show +15? What is the use of E mode ? or which advantages does it over D mode? Thanks in advance, Snappy
Mini_is_Drunk Posted January 16 Posted January 16 (edited) I would personally stick with the D mode, a lot more simpler. If you want to bash your head in for the E mode here is an equation for you: if you use the D mode I normally set it -1 or +1 target alt and I just throw it around from there Edited January 16 by Mini_is_Drunk 1
kontiuka Posted January 16 Posted January 16 (edited) 2 hours ago, Snappy said: Hi, Yes, the radar always shows altitude difference in 1000's of feet whether you are in "E" or "D" mode. That 10 nm trick is just a quick way to figure out the angle but the display is always in 1000's of feet. When you put the radar in "D" mode, you are fixing the altitude difference you want the centre of your radar beam to look at. Wherever you move the alidade, the centre of your radar beam always looks at this altitude difference, causing the radar angle to change. Inside the radome, the radar dish is tilting up and down with the alidade. In "E" mode, you are fixing the angle of the radar beam (even though readout is in 1000's of feet). Wherever you move the alidade, the radar angle remains the same - and you'll notice that the altitude difference changes automatically as the alidade moves. Inside the radome, the radar dish is NOT tilting up and down with the alidade. I agree with Mini above. "D" mode seems more useful especially when you're working with AWACS calls. Edited January 16 by kontiuka 2
Snappy Posted January 18 Author Posted January 18 On 1/16/2025 at 3:37 PM, kontiuka said: Yes, the radar always shows altitude difference in 1000's of feet whether you are in "E" or "D" mode. That 10 nm trick is just a quick way to figure out the angle but the display is always in 1000's of feet. When you put the radar in "D" mode, you are fixing the altitude difference you want the centre of your radar beam to look at. Wherever you move the alidade, the centre of your radar beam always looks at this altitude difference, causing the radar angle to change. Inside the radome, the radar dish is tilting up and down with the alidade. In "E" mode, you are fixing the angle of the radar beam (even though readout is in 1000's of feet). Wherever you move the alidade, the radar angle remains the same - and you'll notice that the altitude difference changes automatically as the alidade moves. Inside the radome, the radar dish is NOT tilting up and down with the alidade. I agree with Mini above. "D" mode seems more useful especially when you're working with AWACS calls. Hi @kontiuka and @Mini_is_Drunk!, thank you both for your explanations, they were helpfu and I understand it a bit better now. Seems to be me that D mode is more practicable in application. I guess E mode is mostly for scanning bigger chunks of airspace for aircraft where you dont have any prelimary target bearing&altitude from GCI or AWACS. Thanks again, Snappy
kontiuka Posted January 18 Posted January 18 (edited) 4 hours ago, Snappy said: Hi ... Hi. I wouldn't even say that E mode scans bigger chunks of airspace. Whichever mode you're in, you're scanning the same cone of airspace and will pick up any targets within that cone. There may be some advantage to E mode but I honestly don't know what it would be. D mode seems more useful since you can manipulate where the dish is pointing with the alidade. EDIT: A good way to train with the radar modes is to set up a mission with a tanker and tune into its TACAN frequency. Since you know the tanker's altitude and TACAN distance, you can manipulate the radar to see if you can find the tanker. Edited January 18 by kontiuka
Snappy Posted January 18 Author Posted January 18 1 hour ago, kontiuka said: Hi. I wouldn't even say that E mode scans bigger chunks of airspace. Whichever mode you're in, you're scanning the same cone of airspace and will pick up any targets within that cone. There may be some advantage to E mode but I honestly don't know what it would be. D mode seems more useful since you can manipulate where the dish is pointing with the alidade. EDIT: A good way to train with the radar modes is to set up a mission with a tanker and tune into its TACAN frequency. Since you know the tanker's altitude and TACAN distance, you can manipulate the radar to see if you can find the tanker. Yes, sorry "bigger" was a bit badly worded , I didnt mean it as bigger than in D mode, I mean it as "large" chunks of airspace. For example, when you fly as a 2 ship formation and want to sanitize airspace ahead, given the radars' 8 degree beamwidth (in 4line scan) , one aircraft could point the antenna 4 degree up in E mode and the other aircraft 4 degree down ,so that the first aircraft would scan everything from level to 8 degree up and the 2nd aircraft scans everything from level to 8 degree down, so there are no detection gaps. Guess you could do that in D mode also, but then you would have to calculate the setting so that the bottom of the beam still scans level at own-ship altitude Thanks , good idea with the tanker mission using its TACAN ! I m gonna give it a try! 1
Mini_is_Drunk Posted January 18 Posted January 18 (edited) also don't forget the Mirage radar also has TWS mode Edited January 18 by Mini_is_Drunk 1
IvanK Posted February 9 Posted February 9 (edited) The E mode is a little different to most other common antenna elevation schemes and would seem to be limited to certain Cyrano IV models ... and the one modeled by Aerges. It is designed for a Constant Antenna selection angle. In other words once set the Antenna elevation is fixed, as you slew the Alidade out in range the numbers displayed represent the altitude covered at that range for that fixed antenna elevation. It so works out that if you set the Alidade to 10nm then the numbers displayed equate to Antenna elevation in degrees. So if you want to set Plus 5 you set the Alidade to 10nm then increase Antenna elevation till it indicates 5. In D mode you select the Altitude you want to scan then radar changes antenna elevation as a function of Alidade range to ensure you cover the selected altitude. Why E mode ? A typical; scenario where this might be useful is A Supersonic /climbing Snap up attack with the R530 (Very Cold war thing). If you are committed to a High Altitude High Energy target (M1.6+ and 50,000' +) it might be your only chance. GCI would set you up on the cut off intercept you accelerate (Rutowski profile) to a desired Energy state. Then at a specific range you "climb" to a specific climb angle pointing at the Collision point. The climb angle designed such that from that point on the Antenna elevation is constant (typically half your climb angle). You the pilot feverishly working the radar looking for the target. With the R530 this was a very intense workload, not having to fiddle with Antenna elevation was one thing you didn't have to worry about. Given the R530's limited range, The radar's limited range, The high closure and then the 1-4sec (random) R530 harmonisation time that takes place after lock on has you rapidly approaching Rmin ! .... "One armed wallpaper hangar stuff" .... Once the lock was achieved the Snap to cancel sight orders and fire occurred. Edited February 9 by IvanK 4
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