HTS FOV/Search Arc limits?

[AvroLanc]

Quick question since it's not in the manual...... What are the Field of View limits for the HTS (Harm Targetting System AN/ASQ-213) search area?

It's obviously not 360 degrees, but what does DCS have modeled? 180 degree forward sector seems to be what I get but maybe it's a little more.... Anyone know the numbers? It's kinda important to know the limits when you're skirting the edge of a SAM's WEZ and need an update for the PGM quality.

Cheers.

Edited April 1, 2023 by AvroLanc

[AvroLanc]

Nobody has tested this? From further testing the AN/ASQ-213 detection cone seems to be actually a bit less than the forward 180 degree sector.

It seems the threat needs to be well inside the forward arc to be detected/updated. Even with very short SCT/scan times (with a single manual threat). It would still be useful if the actual modeled scan/search zone numbers could be provided by ED. Thanks.

[Rei]

Here's my take based on what I can find in the manual.

I'm guessing this has to do with the bottom graphic on page 284 of the manual. Essentially the ALR-56M RWR has a smaller Azimuth Resolution. On the other hand, the HTS AN/ASQ-213's Azimuth Resolution is greater. I'm not sure of the gimbal limit, but I would assume its somewhat close to the limit of the HARM WEZ. In the HAD screen of the HSD it shows the bubble that the HARM can engage in. I would assume that if the target exits this general azimuth it would become an RWR threat and drop off the HTS. If it comes to the RWR it would have a harder time wince the RWR has a smaller Azimuth Resolution.
It seems like very specific possibility but it may be the solution. I think a track file would be good to have, just so the approach angle can be seen in the F10 map and the HAD HSD screen.

That's my take, would love to hear from ED though.

[skywalker22]

FOV for the HTS AN/ASQ-213 may vary depending on the specific implementation and configuration of the system. However, according to publicly available information, the HTS has a wide-angle, stabilized sensor system that provides a FOV of approximately 120 degrees in azimuth and elevation.

[VKing]

11 minutes ago, Temetre said:

On the HSD (not HAD) screen you get an FOV/range symbol using Harms/HTS, maybe thats the FoV? Not sure though. (7:08 in video)

 

The blue sector? That's the Radar FOV.

[Temetre]

vor 42 Minuten schrieb VKing:

The blue sector? That's the Radar FOV.

... nvm may bad xD 

[TEOMOOSE]

On 4/15/2023 at 3:47 AM, skywalker22 said:

FOV for the HTS AN/ASQ-213 may vary depending on the specific implementation and configuration of the system. However, according to publicly available information, the HTS has a wide-angle, stabilized sensor system that provides a FOV of approximately 120 degrees in azimuth and elevation.

"SEAD operations conducted by F-16CJs almost invariably entailed four-ship formations, the spacing of which ensured that the first two aircraft in the flight always looked at a threat area from one side while the other two monitored it from the opposite side. That en- abled the aircraft’s HARM Targeting System, which provided only a 180-degree field of view in the forward sector, to maintain 100 percent sensor coverage of a target area"

Source "Aerospace Power Journal. Volume 16, Number 2, Summer 2002. Talk about the Kosovo War and the continuing sead challenges, 1998-1999. 

 

I dont know what revision "R" hts was in use at that time, but the latest update to my knowledge was around 2007, the revision 7, HTS R7. This is what we have in Dcs World. So the FOV should be the same (( or more ?)) but more accurate, faster, etc. and it allows for use in hts network. 
  

[Tholozor]

45 minutes ago, TEOMOOSE said:

I dont know what revision "R" hts was in use at that time, but the latest update to my knowledge was around 2007, the revision 7, HTS R7. This is what we have in Dcs World. So the FOV should be the same (( or more ?)) but more accurate, faster, etc. and it allows for use in hts network.  

I believe R5 was IOC around 1996, and R6 around 2000.

[Sinclair_76]

As mentioned in this chat:

The HTS FOV according  Aerospace Power Journal Summer 2002 p11 (https://www.airuniversity.af.edu/Portals/10/ASPJ/journals/Volume-16_Issue-1-4/sum02.pdf) is 180° forward sector. Although the HTS variant described is not the R7 (but the R5?). It does not seem realistic to not have the ability to maintain standoff in a more modern version. As anything less than 90° requires the platform to fly towards the target/threat at some angle.

After testing the HTS FOV within DCS I came to the conclusion it is 120°, 60° left and right.

Test setup:

A HTS mounted F-16, hot on ground, with 11 Clam Shells (for elevation guaranteeing LOS) at 360° / +-30° / +- 60° / +- 65° / +- 75° / +- 90°

 

After selecting a radar on the HAD I cycled (with TMS right) through the various emitters and it looped through the 360° / 030° / 060° / 300° / 330°, ignoring the other emitters. At the same time the AN/ALR-56M shows all 11 emitters. Demonstrating the HTS only sees 120°.

Track replay as well as miz included for verification. Nevada because I needed as flat terrain and large LOS as possible.

EDIT: since my bug report has been merged. 

The HTS in DCS has the wrong FOV.

 

Test-HTS-FOV.trk TEST-HTS-FOV.miz

Edited May 2, 2023 by Sinclair_76

[AvroLanc]

2 hours ago, Sinclair_76 said:

As mentioned in this chat:

The HTS FOV according  Aerospace Power Journal Summer 2002 p11 (https://www.airuniversity.af.edu/Portals/10/ASPJ/journals/Volume-16_Issue-1-4/sum02.pdf) is 180° forward sector. Although the HTS variant described is not the R7 (but the R5?). It does not seem realistic to not have the ability to maintain standoff in a more modern version. As anything less than 90° requires the platform to fly towards the target/threat at some angle.

After testing the HTS FOV within DCS I came to the conclusion it is 120°, 60° left and right.

Test setup:

A HTS mounted F-16, hot on ground, with 11 Clam Shells (for elevation guaranteeing LOS) at 360° / +-30° / +- 60° / +- 65° / +- 75° / +- 90°

 

After selecting a radar on the HAD I cycled through the various emitters and it looped through the 360° / 030° / 060° / 300° / 330°, ignoring the other emitters. At the same time the AN/ALR-56M shows all 11 emitters. 

Track replay as well as miz included for verification. Nevada because I needed as flat terrain and large LOS as possible.

 

 

Test-HTS-FOV.trk 427.21 kB · 4 downloads TEST-HTS-FOV.miz 8.79 kB · 2 downloads

 

Thanks for this, nice testing. 

It correlates with what I’ve found in my much less scientific observations. 

[John Galt]

That's some nice work Sinclair, thank you.

[TEOMOOSE]

11 hours ago, Sinclair_76 said:

Demonstrating the HTS only sees 120°.

Excellent finding! Thank you. Hope this issue will be recognized or perhaps it will be fixed with the upcoming hts updates "tdoa".

[skywalker22]

Not true. Take the plane up in the air, and do a proper test, not from the ground.

I did a test yesterday, I had 10 radars along one side of mine in the length of 80nm. I flew all the way near by them, and I saw at least 9 if not 10 constantly all the times, even behind. 

[Sinclair_76]

5 hours ago, skywalker22 said:

Not true. Take the plane up in the air, and do a proper test, not from the ground.

I did a test yesterday, I had 10 radars along one side of mine in the length of 80nm. I flew all the way near by them, and I saw at least 9 if not 10 constantly all the times, even behind. 

Ok...

I took a F-16 up in the air with a similar setup as on the ground but simplified. Four emitters aligned at 0° / -60° / -65° / -90° (true). Aligned at give angles from steerpoint 1. The F-16 was spawned in the air at 25.000' due south (true) from steerpoint 1. So it had to fly 348° magnetic. Once at steerpoint 1 I active freezed DCS to obtain static results. Again the -65° and -90° are not registered by the HTS and the 0° and -60° (+- 2° (ref 298°) at some points) are registered. All 4 emitters are seen by the AN/ALR-56M. This again demonstrates that the HTS scans only +- 60°.

Now for your (@skywalker22) experiment I can only guess. But once the HTS establishes a track or ellips it will remember that even though the HTS reached it's scan limits. So it will remain displayed on the HAD but the ellips will probably not be refined. A emitter will only turn green if no emission has been detected for 2 minutes (per manual p. 286) and be removed after 4. So if you build a track/ellips it will remain visible for up to 4 minutes even while out of scan limits. Hence the "....even behind. "

Miz and track file included for verification and duplication.

 

EDIT

I added a second track file in which I mainted active freeze at stpt 1 for 10 minutes to verify scan limits. The HTS only tracks the 0 and -60° emitters nothing else during the 10 minutes. After the 10 minutes I unfreezed and turned right at heading 003° to get the -60° emitter at -75° active freeze again and see what happens. After 2 minutes the -75° emitter turned green (stale) and after 4 min it disappeared. RWR showing all 4 emitters. Reaffirming that the scan limits for the HTS are +-60° or 120° in total.

 

TEST-HTS-FOV-AIR.miz

Test-HTS-FOV-AIR.trkTest-HTS-FOV-AIR2.trk

Edited May 3, 2023 by Sinclair_76

[skywalker22]

On 5/3/2023 at 9:23 AM, Sinclair_76 said:

Ok...

I took a F-16 up in the air with a similar setup as on the ground but simplified. Four emitters aligned at 0° / -60° / -65° / -90° (true). Aligned at give angles from steerpoint 1. The F-16 was spawned in the air at 25.000' due south (true) from steerpoint 1. So it had to fly 348° magnetic. Once at steerpoint 1 I active freezed DCS to obtain static results. Again the -65° and -90° are not registered by the HTS and the 0° and -60° (+- 2° (ref 298°) at some points) are registered. All 4 emitters are seen by the AN/ALR-56M. This again demonstrates that the HTS scans only +- 60°.

Now for your (@skywalker22) experiment I can only guess. But once the HTS establishes a track or ellips it will remember that even though the HTS reached it's scan limits. So it will remain displayed on the HAD but the ellips will probably not be refined. A emitter will only turn green if no emission has been detected for 2 minutes (per manual p. 286) and be removed after 4. So if you build a track/ellips it will remain visible for up to 4 minutes even while out of scan limits. Hence the "....even behind. "

Miz and track file included for verification and duplication.

 

EDIT

I added a second track file in which I mainted active freeze at stpt 1 for 10 minutes to verify scan limits. The HTS only tracks the 0 and -60° emitters nothing else during the 10 minutes. After the 10 minutes I unfreezed and turned right at heading 003° to get the -60° emitter at -75° active freeze again and see what happens. After 2 minutes the -75° emitter turned green (stale) and after 4 min it disappeared. RWR showing all 4 emitters. Reaffirming that the scan limits for the HTS are +-60° or 120° in total.

 

TEST-HTS-FOV-AIR.miz 7.82 kB · 0 downloads

Test-HTS-FOV-AIR.trk 1.25 MB · 0 downloads Test-HTS-FOV-AIR2.trk 1.89 MB · 0 downloads

 

Indeed I have to apologize, you were correct. I completely forgot that emitters colored green mean that they are actually not active, as you also stated. And as you already figure it out with your test, HTS has an azimuth scan of APPROX. 120degrees in total.

I did some serious calculations using angular functions stuff, and after that did some "meter by meter" tests in DCS to fine tune when the HTS sensors starts seeing emitters. And this is what I came up with:

- horizontal aspect: 130deg (+-65deg)

- vertical aspect: 111,4deg (+-55,7deg) 

So its not an actual circle what the sensor really see, but its a bit of an oval (cone). 

Edited July 7, 2024 by skywalker22

[Default774]

1 hour ago, skywalker22 said:

Indeed I have to apologize, you were correct. I completely forgot that emitters colored green mean that they are actually not active, as you also stated. And as you already figure it out with your test, HTS has an azimuth scan of APPROX. 120degrees in total.

I did some serious calculations using angular functions stuff, and after that did some "meter by meter" tests in DCS to fine tune when the HTS sensors starts seeing emitters. And this is what I came up with:

- horizontal aspect: 130deg (+-65deg)

- vertical aspect: 111,4deg (+-55,7deg) 

So its not an actual circle what the sensor really see, but its a bit of an oval (cone). 

Regarding what we have in HAD mode in DCS: I really don't know where does this shape, of what HTS sensor should see, comes from:

Should it really look back, over 180degrees in total?  So far we are far from that as we figured it out. That shape looks closer to 200deg.

 

That shape is the HARM engagement envelope in EOM. Switch your HARMs to PB and it will change