Radar Operation Guidelines in knowledgebase has missing images

[+streakeagle 867]

The Imageshack host of all my online images is no longer free and slowly deleting/blocking re-posting of all the images I had uploaded over the years. The SF radar tutorial that I had posted here (a locked thread in the knowledge base) and at Third Wire is now missing most/all of the images. Bunyap's Weapons Delivery Manual still has the full tutorial if you can find that in the downloads.

I have recovered most of the images from imageshack and grabbed the first two that were missing from Bunyap's manual, so here is a repost using CombatAce uploaded images:

 

Using radar and radar homing missiles like the AIM-7 Sparrow on Hard settings seems too hard for many people. With a little review of the way radar works and what the display indications mean, it really isn't that difficult.

A basic summary:
1. Use Search Mode to detect a target on your display (vary the range scale using the <PAGE DOWN> key if necessary).
2. Use the <HOME> key to move the cursor to the target.
3. Use the <INSERT> key to lock on.
4. Center the steering dot in the ASE circle.
5. Launch when "IN RANGE".
6. Maintain target lock on until missile hits, or missile will miss.

Note: Once you have locked on, you can use <CTRL><R> to visually acquire the target, which also identifies the type of aircraft (an unrealistically accurate form of IFF). Then use either <F4> to padlock the target from within the cockpit, <SHIFT><F8> to padlock the target from an external player-to-target view, or <F8> to see the target up close.

Alternatively, steps 1 through 3 can be bypassed when engaging targets held visually: Select Boresight Mode and hold your gunsight exactly on the target until a lock on occurs. Then continue with step 4.

The idea behind radar in the 1960s was that radio energy could be used to search for contacts by rapidly sweeping an antenna from side to side while transmitting radio energy pulses and receiving "echoes" from targets hit by those pulses. The antenna has a "beam", which is the pattern or shape of the radio transmission. Ideally, this beam is very narrow since it determines the elevation and azimuth resolution. The radar display graphs the azimuth (bearing) of the antenna versus the time (range) of the echoes. In the case of the F-4 radar as portrayed in SFP1 and WOV, the elevation of the antenna alternates between a look up and a look down angle. Each elevation angle is referred to as a bar. The F-4 radar's search pattern in SFP1 and WOV is a 2-bar scan.

The F-4 has radar azimuth limits of +/- 60 degrees, which means it can see targets in a 120 degree cone centered on its nose.

Illustration of horizontal aziumth sweep pattern:


The 120 degree horizontal search cone is quite large, but not every target will be covered by it. There are four ways to get a target into your seach sweep:
1. Arbitrarily change course by +/- 120 degrees to cover a full 360 degrees. In reality, you should know what is behind you, so check turns of +/- 60 degrees is probably adequate.
2. Point your nose at RWR contacts.
3. Steer to the targets in the verbal reports from the ground controller.
4. Use the <M> key to bring up the map to see where to turn your nose to acquire targets known to ground control.

The F-4 has radar elevation limits of +/- 60 degrees, but does not scan over that entire range. It merely permits the radar to continue a full horizontal sweep when banked 90 degrees. The vertical search is constrained to two elevation bars at +/- 1.875 degrees. The radar beam is 6.7 degrees wide and the two elevation bars overlap providing about 10 degrees of vertical coverage.

Illustration of 2-bar vertical sweep pattern:


While this was outstanding for its day, it is easy to see that targets might be above or below the 10 degrees of vertical search. The F-4 must periodically pitch its nose up or down to get more vertical coverage. Of course, the F-4 does not have look-down radar. If the nose is pointed down too much, the radar will be cluttered heavily with ground returns. In reality, the F-4 had major problems trying to use the radar and Sparrow missiles at low altitudes or against targets flying at much lower altitudes. The game is not quite so picky, but a target can try flying very low and using ground clutter to break lock ons and/or decoy Sparrows.

Here is a typical search display from an F-4 radar in SFP1 with two targets:


Once you have found a target on your search display, you have the option to acquire/track/lock on to the target. This means the radar stops sweeping rapidly and instead tries to keep the antenna pointed at the target at all times. This provides very accurate information on a single target, which is needed to launch and guide radar guided missiles such as the AIM-7 Sparrow. Tracking a single target does not permit searching for more targets.

The F-4 radar has a cursor that allows you to choose which target you want to acqire. Press the <HOME> key to move the cursor. If the cursor is not on the desired target, then continue pressing the <HOME> key until the cursor is on the desired target.

Here is what happens if you push the <HOME> key while a target is displayed (the cursor moves to the target):


Once the cursor is in the desired position, simply press the <INSERT> key to track/acquire/lock on to the target. The sweeping strobe stops on the bearing of the contact, all other targets disappear from the display, and a range gate sweep moves up the strobe until it finds the target's range. At that point, lock on has been achieved.

Here is what happens if you push the <INSERT> key while the cursor is on a target (the radar enters acquisition mode):


If you successfully lock on, the radar displays additional information: closure rate using a rotating ring, allowable steering error, steering dot, and the min and max ranges of the selected weapon. There is even an IN RANGE light to let you know when the target is within firing range parameters.

The notch in the range rate circle rotates to indicate closure rate. If the notch is at 12 o'clock (top of the circle), then there is no closure. As the notch moves clockwise from 12 to 3 to 6 to 9, it indicates an increase in the closure speed. As the notch moves counter-clockwise from 12 to 9, it indicates that the target is opening rather than closing. In other words, the target is moving away from the radar.

Here is what the display looks like while locked on:


Sparrows have two primary launch requirements:
1. Locked on to the target. 
2. Target between Min and Max range limits.

But just because you are able to launch a Sparrow, doesn't mean it has a chance of hitting. Other launch requirements that should be considered include:
1. Launching aircraft should not be maneuvering violently.
2. Steering dot should be within the ASE circle.
3. ASE circule changes size with range. In general, the larger the circle, the better the chance to hit. Try to hold fire until the circle is close to its maximum size.
4. Aspect of the target can render Sparrow shots impossible. The AIM-7 likes direct head-on shots form long distances and rear quarter shots from short distances. Crossing shots at the targets front quarter and beam may prove difficult, if not impossible to hit.
8. Launching aircraft should have as high a speed as practical since the missile can maneuver better, fly longer range, and impact sooner if it has more energy at the moment of launch.

Here is what the F-4 radar display looks like when close to optimum firing conditions (the ASE circle is very larget and the steering dot is almost centered in the circle):


If you get too close to fire an AIM-7 Sparrow, the radar displays a big "X" (the phrase "too close for missiles, switching to guns" should come to mind):

 

Edited January 10, 2016 by streakeagle

[Wrench 9,764]

Streak;

I approved it, and changed the title to "How to Use Radar". Also added the caveat, "post any comments/questions in the main SF2 Forum, General Discussion". Otherwise, the KB will be full of stuff (discussion, etc) that don't belong there

 

thanks for rescuing the images!

[+streakeagle 867]

I knew the images were slowly going away. But I had a private message requesting a fix. It took a few minutes, but hopefully, with CombatAce hosting the images, it won't degrade over time again.

Unfortunately, the F-15A radar and SF2 RWR strobe addendums in the same thread at Third Wire are also completely wiped. I think I still have the gif files showing the RWR, though. Don't know if anyone would like it reposted?

[Wrench 9,764]

I would go ahead and do it anyway. It's bound to help someone, at some point in time

[+streakeagle 867]

If I can still edit the new post, I will append the RWR info.

[+streakeagle 867]

Wrench, if you could modify the title in the knowledge base post to reflect the inclusion of the RWR examples, that would be great.

 

Perhaps the title of the thread should be:

SF Series Guide: How to Use the F-4 Radar and RWR

Edited January 10, 2016 by streakeagle

[jeanba 1,920]

 

 

Note: Once you have locked on, you can use <CTRL><R> to visually acquire the target, which also identifies the type of aircraft (an unrealistically accurate form of IFF).

This is not fun at all !!!

[KJakker 886]

Thank you for the update Streakeagle. 

[+streakeagle 867]

I love this sim and if it doesn't take too much time, I am more than willing to help when others request it. If I wasn't spending most of my time flying DCS, I would love to go back and make a dedicated flight manual for each aircraft, mixing the real-world flight manuals I own with the stock flight model and system behavior of the game. Despite the "lite" aspect in some areas, TK should never have called the SF series "lite". In many ways, it was much closer to a hard core sim than LOMAC/Flaming Cliffs, especially for aircraft that didn't have multi-function displays. The user controls may be simplified, but the cockpits of F-4 and earlier aircraft are extremely close to fully functional in terms of displays/indications and the original missile performance and unreliability that got nerfed after SF2NA was more realistic than any PC sim I have ever flown. Only in the last couple of years has DCS surpassed the SF series in overall realism of flight modeling. It is still working on catching up to SF in weapons modeling. DCS has taken over my F-86/MiG-15/MiG-21 flight simming, but SF2 is still the one and only place to go for Vietnam and the 1950s with the F-4, F-8, F-105, F-111, A-4, A-6, A-7, and the whole Century series. I can only dream of a DCS F-101 Voodoo, but I have spent countless hours using Genies to nuke incoming Soviet bombers with the F-101B in SF2 or intercepting/dogfighting MiGs in the F-101A/C. The terrain is so dated, but the gameplay in terms of large scale air-to-air fights remains top notch compared to the competition.