The Radar model correct ?

[assafm25]

Hi All ,

 

Is the Radar model is correct for this mod?

 

i found it real anus-full in any combat and just spent my time and continents looking for target .

[SkateZilla]

What Type of Radar are you expecting from a Early 60's Era Aircraft?

[Pocket Sized]

Yes.

 

It's a very lightweight, early radar system. It has no look down shoot down capability and has a very short detection range due to its low power.

 

You need to be at or slightly below the target and close enough to pick them up on radar (less than 20 miles or so). If the target is far above you, the antenna has to be driven up using the radar elevation control.

[The M]

I noticed that it takes a long time to get a lock in the short range missile and gun mode. I keep the target in front of me but sometimes i allmost have to fly into the enemy to get a lock with the gun mode

[Fionn]

I find if you reset out of the mode and then reselect the DG mode it will acquire, but if you just leave it in the DG mode it does not.

[The M]

I know but it takes way too long sometimes.

[escaner]

What Type of Radar are you expecting from a Early 60's Era Aircraft?

Maybe one that locks the target when you command a lock with the cursor on a contact?

TBH it has been a long time since that last worked for me.

[Pocket Sized]

Again, it depends on the circumstances.

 

Remember the radar has ZERO resistance to ground clutter. If your target is between you and the ground the chances of getting a lock decrease proportionally with their altitude and inversely with range.

 

In other words if the target is a long way away and very low the chances of seeing or locking them are tiny, even more so if you're diving on them. That's not to say it's impossible to lock somebody below you. If you're in close and at high altitude the radar will easily be able to pick out the target.

[Moafuleum]

I also noticed some strange behavior of the radar regarding the adjustable antenna angle. It seems to me that the angle you govern, is always with respect to the horizon line and not to your aircraft's nose. In other words, your plane's attitude does not play a role, only if your target is below or above you (altitude-wise).

I don't think that the antenna is horizon-stabilized actually. Has someone else noticed this? You can easily check this during a climb or dive towards another plane while keeping a constant approach angle to it and making shure you see it at the beginning of your climb/dive. If you dont move the antenna's angle, after a while it is disappearing but it shouldnt since you kept the approach angle always constant.

[Kev2go]

What Type of Radar are you expecting from a Early 60's Era Aircraft?

 

1970s...

 

An/APq 153 that was intalled on the F5E it went into service with ther airframe in 1973. and the newer AN/APQ 159 series came later. So weak or not its technically a 70s radar, and the aircraft while based cloesly on the earlier F5A, has a few improvements, & again is being produced in the early 70s.

 

It has less to do with the date, but more with the fact its small size. F4 phantoms that came earlier than the F5E, all had a considerably better radar, because its larger size allowed for a larger more powerful radar. Even if the designers werent intending the F5 to be a cheap economical Export fighter, there just wasnt much more powefull radar that you could stuff into it, with the technology available at the Time of its introduction.

 

That aside to those complaining, Its radar still better than that of the Mig21bis. Offers longer range, off boresight racking/lock , setting between 30 degrees upwards/ downward antenna tilt. ground clutter also affects the F5s An/APQ 159 radar noticeably less than the Migs Saphir at altitudes under 2000m. But yeah compared to 4th gen fighters like the m2000 or FC3 aircraft like the F15, yeah its underwhelming. but that can be expected.

Edited December 1, 2016 by Kev2go

[SkateZilla]

When they became Active Status in an Airframe and when they were developed, are two different dates.

[escaner]

When I cannot lock my leader that is flying 3-4 miles ahead of me, and then switch to dogfight boresight and immediately locks, its is not problem with range of ground clutter.

[Ala12Rv-watermanpc]

I also noticed some strange behavior of the radar regarding the adjustable antenna angle. It seems to me that the angle you govern, is always with respect to the horizon line and not to your aircraft's nose. In other words, your plane's attitude does not play a role, only if your target is below or above you (altitude-wise).

I don't think that the antenna is horizon-stabilized actually. Has someone else noticed this? You can easily check this during a climb or dive towards another plane while keeping a constant approach angle to it and making shure you see it at the beginning of your climb/dive. If you dont move the antenna's angle, after a while it is disappearing but it shouldnt since you kept the approach angle always constant.

 

+1. Thats exactly what I noticed also in some test flights I made...it seems like the antenna angle is linked to the horizont.

[Pocket Sized]

+1. Thats exactly what I noticed also in some test flights I made...it seems like the antenna angle is linked to the horizont.

 

Every movable nose mounted radar in dcs does this, and the real documentation says it should.

[escaner]

Every movable nose mounted radar in dcs does this, and the real documentation says it should.

 

Nope, the manual says it is referenced to the ARL.

See attachment.

[Ramsay]

Nope, the manual says it is referenced to the ARL.

See attachment.

 

In search mode the antenna is ground stabilised.

 

RADAR OPERATION

SEARCH PHASE

...

The antenna is pitch and roll stabilised so the azimuth scan is a plane parallel to the earth surface regardless of aircraft roll attitude, preventing loss of the target and/or smearing of the display.

Source: TO 1F-5E-34-1

 

or

APQ-153, NASA Test Report, older F-5E radar type (page 16)

2.2.2 Operate

Search - The antenna will initiate a scan and search through its horizontal angle of + 42.5° and the vertical two-bar controllable through an angle of + 45° to -35°.

 

The horizontal and vertical coverage may be shortened due to gimbal limits that are a function of aircraft pitch and roll angles. The antenna scan is space stabilised. The antenna is commanded in elevation with the elevation control located on the Set Control.

 

The antenna scans through a two-bar (+1.5°) elevation pattern as shown in Figure 2.5. The tilt cursor symbol indicates the antenna command referenced to the earth's horizon.

 

Source: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19750008534.pdf

[escaner]

Well, then it is the module manual in this case what is wrong.

[Ala12Rv-watermanpc]

Ok, so its stabilised to horizon, that explains its behaviour...

 

Btw, any tips on how to efectively use F5 radar??

 

...also, how much time shoud I wait for a contact to show itself in the screen before moving again the tilt angle??

 

I ask this because I cant see a clear relation between actualization vertical bar and the contacts representation so some times it takes longer than others to show things which makes it hard to search...

[Ramsay]

...also, how much time shoud I wait for a contact to show itself in the screen before moving again the tilt angle??

 

Radar detection ranges are often given in terms of probability, the more often you scan a section of airspace, the higher your chance of detecting a target. How long you give is dependent on closure rate, tactics, etc., you may not detect the target on your own radar before you have merged.

 

If you were to fly towards a 2 m² target from 20 nm, and were told you had a 85% cumulative probability of detecting it at 12 nm, the radar beam would scan the target several times. You might detect the target sooner (i.e. at R50cum) or later (R95cum). There's no guarantees, only increasing probability in your favour.

 

 

I ask this because I cant see a clear relation between actualization vertical bar and the contacts representation so some times it takes longer than others to show things which makes it hard to search...

It's to be expected as it may take several scans to detect a target.

[lmp]

When I cannot lock my leader that is flying 3-4 miles ahead of me, and then switch to dogfight boresight and immediately locks, its is not problem with range of ground clutter.

 

I think I know what your problem is. MSL mode has essentially three phases: searching, acquisition and tracking. The manual has this to say about the antenna scanning pattern in the search phase:

 

40-mile range. Antenna scan covers 90° in azimuth and 4 degrees below and above antenna centerline.

 

20-, 10- and 5-mile range. Antenna scan covers 90° in azimuth and 5.5 degrees below and above antenna centerline.

 

And now the scanning pattern in acquisition phase:

 

Pressing ACQ button (located on AN/APQ–159 control panel) spotlights target. Range scale automatically changes to 10. Antenna starts scanning ± 5 degrees in azimuth and ± 1.5 degrees in elevation.

 

See the problem? In the acquisition phase the radar scans significantly less space in elevation (within 1.5 degrees of your antenna centerline, versus 5.5 in search). So if, say, your target is 2 degrees above your antenna centerline, you will see it in search but acquisition will NOT lock.

 

Idea for BST - emphasize this potential problem in the manual more. I have a feeling people will keep running into this.

Edited December 4, 2016 by lmp

[escaner]

See the problem? In the acquisition phase the radar scans significantly less space in elevation (within 1.5 degrees of your antenna centerline, versus 5.5 in search). So if, say, your target is 2 degrees above your antenna centerline, you will see it in search but acquisition will NOT lock.

 

Thank's Imp, that certainly could be the problem.

Is there any trick to help with the lock, then? Maybe move the antenna up and down while in acquisition phase?

[lmp]

You could try that, might work. I've contemplated the idea but never got around to doing any tests. If you know the exact altitude of your target, you could just match it and set the antenna tilt to 0. Personally, unless I'm intercepting a big bomber, I don't bother trying to lock it in MSL mode. Against fighters I use it as a situational awareness mode and rely more on DM and DG to get a firing solution.