HOT Elevation For CCIP Bombing

Based on the great information provided by some of the folks posting in JayPee's Looking for comprehensive dumb bombing guides thread (e.g. Eddie, Noodle, etc.), I have managed to notably improve my CCIP bombing and canon runs. :joystick:

However, one piece of information has remained somewhat opaque. I posted this question in the original thread here, but none of our resident SMEs have responded yet. Since it's buried in a rather long thread, and may be helpful to many other Hog pilots, I thought this question may deserve its own stage. :smartass:

In particular, I'm trying to determine if there is a more accurate method of specifying target elevation. By default, the CCIP solution appears to utilize DTS for elevation. However, the thread above made oblique references to HOT elevation entries that are virtually absent from the flight manual. For example:

Pro Tip: It's always better to use HOT elevation with the actual target elevation than to rely on the DTSAS Auto Elevation function (often referred to as "DTS").

The only entry for "HOT elevation" I could find is on page 205 under the SYSTEM / LASTE Sub-Page subsection. Searching for "target elevation" in the flight manual reveals some guidance on manually modifying the height of the current steerpoint via the UFC. Alas, my attempts to search this forum (and Google) for more robust descriptions haven't been that helpful either. :book:

The DCS A-10C Warthog FAQ offers the following reference:

In order for the IFFCC to compute a CCIP solution, it must know the elevation under the CCIP pipper (gun, rocket, bomb, etc.). This can either be a HOT elevation based on the Steerpoint elevation, or DTS elevation stored in the digital map database system. If not in DTS and the steerpoint is at a higher elevation than the CCIP pipper, you will get a CCIP INVALID message. Unless you have a DTS failure, you should always use DTS, as indicated on the HUD in the data block. If you do not see DTS, press the DATA rocker on the UFC and then the SEL rocker until DTS appears.

Thus, I would like to pose the following question(s) to the experts in our community: what is HOT elevation, when/how would I use it, and is it better than DTS for CCIP bombing and cannon runs? :helpsmilie:

tl;dr answer/update:

Without target elevation your bombing sight will be inaccurate. If DTSAS is operating properly you should not care about it as DTSAS determines elevation automatically. It is called DTS elevation.

 

Once DTSAS is failed, or is off map, or simply is turned off, you will have to enter target elevation manually into a waypoint, and then to set it as steerpoint to get bombing sight operating properly. This is called HOT elevation. The elevation also can be edited via UFC by DATA switch when HOT elevation is the currently selected elevation mode.

 

Sometimes DTS elevation works incorrectly. Typical example is mountainous terrain. It this case it is practicable to select HOT elevation option and then to set your target waypoint as steerpoint.

I've been dutifully studying the same thread and texts that you refer to, and I believe that, based on the T-45 Weapons/Strike manual where HAT is Height Above Target, "HOT" likely means Height Over Target. Despite the way it seems to be used in this context as a label for a different kind of elevation reference, e.g. as opposed to say DTS or TGP, it seems to me that HAT/HOT is simply a term describing one of the inputs into the IFFCC's CCIP solution no matter WHAT the elevation reference. For example even when using DTS as the elevation reference, the IFFCC still needs to calculate a Height Over Target in order to produce a valid CCIP solution.

The difference between the two is simply that in the case of DTS you're relying on a preconfigured database to find/estimate the local elevation in the vicinity of the target; with "HOT elevation", you're manually inputting the [presumably more accurate] actual target elevation in order to allow the IFFCC to produce a more accurate solution. As a counterpoint to the quote you have above that recommends not using DTS, I've also read elsewhere that DTS should be used in the majority of cases where you will likely not be able to determine the target elevation any more accurately than DTS would. The exception to this case would be on a known target range, where very accurate elevation data is likely known.

Hey,

also, remember that the pro guys tend to do stuff because it is done like this in real life, not neccersarily because it gives them an actual advantage in the simulation. So while in real life DTS data may easily be more inaccurate than newly measurements by ground personel, i tend to think that inside DCS all hight sources are the same. Meaning JTAC and DTS in game probably both rely on the same hight map.

So it might just be a thing of doing stuff "by the book".

Madog

Hey,

also, remember that the pro guys tend to do stuff because it is done like this in real life, not neccersarily because it gives them an actual advantage in the simulation. So while in real life DTS data may easily be more inaccurate than newly measurements by ground personel, i tend to think that inside DCS all hight sources are the same. Meaning JTAC and DTS in game probably both rely on the same hight map.

So it might just be a thing of doing stuff "by the book".

 

Madog

I think what Madog has posted here is exactly the case. In a 9 line you are given target elevation from the JTAC that in thr real worls is more than likely going to be more accurate than that of a DTS which contains a worldwide database of various accuracy to 1m res. It appears that the game introduces no 'error' to DTS data, so (from what I have seen at least) it is more than adequate for weapon solution.

DTS can give you wrong target altitude in some cases. DTS database has lower resolution than the DCS terrain and in places where the terrain slope changes abruptly DTS can give wrong enough altitude to make it impossible to hit close enough of a tank to kill it unless releasing from a very steep dive. I have also encountered some areas where the terrain is flat but the DTS altitude is still tens of meters wrong. You can easily test the difference of DTS and DCS terrain altitudes by first making a mark point on ground using TGP without lasing, and then another while lasing and comparing the altitude coordinates of the two markpoints.

You can get accurate terrain elevation by lasing the spot on the ground with TGP. The aircraft knows it's position by EGI and with TGP you can measure distance and direction to the target hence it's possible to calculate the 3D coordinates of the TGP target very accurately. You can either read the elevation from TGP and input it manually or create a mark point, select it as steerpoint and enter HOT elevation mode and it will automatically suggest the mark point elevation.

Thanks for all of the input, gents! :thumbup:

I'm assuming from this point on that "HOT" has two possible meanings: (1) a target elevation entered quickly (i.e. on the fly) - thus "hot" or (2) height of target. In either case, the implications are basically the same for our purposes.

You can get accurate terrain elevation by lasing the spot on the ground with TGP. The aircraft knows it's position by EGI and with TGP you can measure distance and direction to the target hence it's possible to calculate the 3D coordinates of the TGP target very accurately. You can either read the elevation from TGP and input it manually or create a mark point, select it as steerpoint and enter HOT elevation mode and it will automatically suggest the mark point elevation.

I'm familiar with how to read elevation from the TGP, but I'm not so clear on how to use it for CCIP bombing. Based on your description above, it sounds like I can manually enter an elevation. The only way I can think to do this is to use DATA and SEL rockers on the UFC, and in this manner I'm only able change elevation in tens of meters (i.e. 10, 20, 30, etc.). I'm not clear on why TGP-derived markpoint elevation is helpful; to my knowledge, the CCIP targeting solution will not use the TGP data or any markpoint information. I tried to use your TGP-derived markpoint method with a subsequent HOT elevation entry from the UFC, but the elevation still only adjusts in tens of meters. Am I missing something?

As an aside, the flight manual suggests that the ENT button on the UFC does the following: "Enters a target elevation update for the current steerpoint." When I press enter, I get a 0D and a 0G on the HUD. Does anyone know what this means?

On a related note, should I be selecting a particular altitude source on the AHCP? My intuition is suggesting that a radar-derived aircraft altitude would be more accurate for CCIP bombing than barometric or delta. Thoughts?

You can manually enter HOT elevation by first pushing DATA rocker so that the DTS changes into blinking altitude reading (altitude of the currently selected steerpoint), then write the desired altitude to the scratchpad using UFC or CDU and press enter. If you don't like to manually input it down or use the rocker to change it in 10 increments you can create a markpoint (remember to use laser) over the target and select it as steerpoint so when you push DATA rocker it will give the correct altitude as initial value.

TGP gives basically GPS altitude of the point in the ground when you measure the range with laser, otherwise it gives the same altitude as DTS would. Radar altimeter gives height of ground under your aircraft and it can't see the ground if you dive in steeply or are too high.

You can manually enter HOT elevation by first pushing DATA rocker so that the DTS changes into blinking altitude reading (altitude of the currently selected steerpoint), then write the desired altitude to the scratchpad using UFC or CDU and press enter. If you don't like to manually input it down or use the rocker to change it in 10 increments you can create a markpoint (remember to use laser) over the target and select it as steerpoint so when you push DATA rocker it will give the correct altitude as initial value.

 

TGP gives basically GPS altitude of the point in the ground when you measure the range with laser, otherwise it gives the same altitude as DTS would. Radar altimeter gives height of ground under your aircraft and it can't see the ground if you dive in steeply or are too high.

Thanks again for your help. I tried both approaches, but in each case it does not seem to work. I'm using an example near Batumi. The target is at an elevation of 33 feet; DTS indicates 31 feet. I then hit the DATA rocker to put it into manual mode, then enter the height into the UFC scratchpad and press enter. However, the blinking height indication stays on 30 feet in the HUD. The same is true when I attempt this using your markpoint method; my blinking height shows up as 30 when I hit the data rocker from the laser-derived markpoint height.

It will round to the nearest 10.

There are differences between DTS and the actual elevation .... most interesting, I wasn't aware of this. I always thought that DTS would just use the terrain data and thus was always 100% correct.

That could also explain some of the difficulties that people experienced in those infamous "wind corrected dumb bomb delivery"-treads. Hrm, guess that is something worth checking out again.

There are differences between DTS and the actual elevation .... most interesting, I wasn't aware of this. I always thought that DTS would just use the terrain data and thus was always 100% correct.

 

That could also explain some of the difficulties that people experienced in those infamous "wind corrected dumb bomb delivery"-treads. Hrm, guess that is something worth checking out again.

Indeed. I wasn't aware of any distinction until I read JayPee's Looking for comprehensive dumb bombing guides thread on CCIP bombing. The following guidance from BlueRidgeDx was what initiated my quest for more information.

Pro Tip: It's always better to use HOT elevation with the actual target elevation than to rely on the DTSAS Auto Elevation function (often referred to as "DTS").

Although the answers above have helped (specifically that HOT elevations can only be adjusted in integer multiples of 10 from the UFC), it would be great if someone with more experience could add some detail.

As for HOT elevation itself, I just found the following post:

Without target elevation your bombing sight will be inaccurate. If DTSAS is operating properly you should not care about it as DTSAS determines elevation automatically. It is called DTS elevation.

 

Once DTSAS is failed, or is off map, or simply is turned off, you will have to enter target elevation manually into a waypoint, and then to set it as steerpoint to get bombing sight operating properly. This is called HOT elevation. The elevation also can be edited via UFC by DATA switch when HOT elevation is the currently selected elevation mode.

 

Sometimes DTS elevation works incorrectly. Typical example is mountainous terrain. It this case it is practicable to select HOT elevation option and then to set your target waypoint as steerpoint.

This might mean it's better to turn DTS off and just use markpoints or waypoints to bomb in CCIP mode. This is particularly true if the HOT elevation resolution is limited to 10-meter increments when entered from the UFC. Some in this thread have suggested this, but I didn't think the CCIP solution would utilize elevation information from a steerpoint. Thoughts?

He's referring to the procedure where you use the steerpoint as an aid to set the HOT elevation. CCIP will use either DTS or the HOT elevation, it will not care about your steerpoint elevation. You don't need to worry about 5 feet error in target altitude as if your bomb comes in at very shallow 30 degree angle of the ground, it will impact 9 feet short or long at max. In a typical CCIP delivery your bombs would be coming in at about 45 degree angle which means 5 feet error in impact point.

He's referring to the procedure where you use the steerpoint as an aid to set the HOT elevation. CCIP will use either DTS or the HOT elevation, it will not care about your steerpoint elevation. You don't need to worry about 5 feet error in target altitude as if your bomb comes in at very shallow 30 degree angle of the ground, it will impact 9 feet short or long at max. In a typical CCIP delivery your bombs would be coming in at about 45 degree angle which means 5 feet error in impact point.

Great - thanks again for your help!