PVI-800 Manual input accuracy

[Cheetah7798]

I've been flying the Ka-50 for quite some time now and I'm willing to say that there's only a short list of things left in the shark that can surprise me. That said, there is something I've always wondered.

 

The PVI-800 is a great nav system. Flip the INU switch up, pan the shkval to something, lase it, hit "un-cage"; bam! got yourself a set of pin-point coordinates for later reference.

 

 

 

Now, what about manual entry?

 

Question No. 1:

How accurate is the PVI-800's manual input?

 

Something that's immediately apparent is that the PVI-800's display only shows coordinates down to a tenth of a minute. My question is, does it accept further input beyond what is displayed, or is all input beyond the tenths place just some overflow that gets wiped after you hit the next 0, 1 or 'enter'. I mean, considering the resolution you get from a Shkval based entry, I would hope greater coordinate accuracy was possible than to the nearest tenth of a minute.

 

 

 

Question No. 2:

During manual input, can you account for altitude?

 

There is, seemingly, some hidden reference to altitude in the PVI-800, since a Shkval based entry gives accurate reference to a position, regardless of altitude (in my experience). However, when entering coordinates manually, I am almost always left with a target point that is either suspended above the target, or deep beneath them. Is there a way to adjust this?

 

 

 

 

 

In closing, a scenario I see crop up often enough is one where I know of a [threatening] target beyond the 15km limit of the laser's range-finding potential, which also happens to be obstructed (by trees, hills or mountains). For an example, let's use a Buk emplacement. Being able to punch in a set of target coordinates, confident that when you fire up your Shkval, it'll put the target at least somewhere on the screen, would be an awesome capability to have. Sure, there are alternatives, but this appears to be the least taxing on the pilot, as most of the work is done prior.

[randomTOTEN]

We're gonna need some comment from the developer to know for sure, but I thought you should at least get some sort of reply :smilewink:

Best I can offer you is some speculation on my end. Hopefully others can chime in.

My question is, does it accept further input beyond what is displayed,

I would assume the answer is no. DDD°MM.M is the most you can enter, and I would assume it's the most accurate that form of entry is. The manual makes no mention of a "precise" entry mode best I can tell, so I would assume that one doesn't exist.

or is all input beyond the tenths place just some overflow that gets wiped after you hit the next 0, 1 or 'enter'.

Seems the display reacts to no further key inputs once it is filled.

I mean, considering the resolution you get from a Shkval based entry, I would hope greater coordinate accuracy was possible than to the nearest tenth of a minute.

That's probably a simplification of the KA-50 INS. It appears very basically simulated, with no drift, really no alignment procedure other than elapsed time. It probably doesn't model any kind of accuracy limitations whatsoever. The only restriction is on the number of numbers you can type. It's probably perfectly accurate (uses same position information the rest of the simulation uses for calculations).

Question No. 2:

During manual input, can you account for altitude?

I don't see any way to.

There is, seemingly, some hidden reference to altitude in the PVI-800, since a Shkval based entry gives accurate reference to a position, regardless of altitude (in my experience).

Don't know how the real Ka-50 INS does it.. but I highly suspect the INS is using raw elevation data from the terrain file. I.E. checks elevation at defined position, and uses that directly.

However, when entering coordinates manually, I am almost always left with a target point that is either suspended above the target, or deep beneath them.

Do you mean you're manually entering the position of the 10 Target Points (TP/OT)? How are you getting these points to display? Ingress to Target? I would be under the impression they were 2D only.

Being able to punch in a set of target coordinates, confident that when you fire up your Shkval, it'll put the target at least somewhere on the screen, would be an awesome capability to have.

If this is a SP mission you should also have the ability to directly place the TP in the editor. That should give you perfect accuracy and hopefully perfect elevation data too...

 

Are these TP's displayed on the ABRIS? In that case you could also manually move the Shkval to have the yellow gate overly the TP and use terrain features to fine tune the alignment. That would help with a sneaky pop-up attack.

[flanker0ne]

Question No. 2:

During manual input, can you account for altitude?

 

 

No (Saddly), and I think it's a huge void in the tactical employment of the asset.

Any time I move from a shore zone to a more hilly or mountaineous zone, the lack of altitude input, need particular skills.

[Cheetah7798]

randomTOTEN, flanker0ne, thank you both for your input, though it is unfortunate that most of my suspicions about the system appear to be confirmed.

 

 

Now, specifically responding to your questions, randomTOTEN:

Do you mean you're manually entering the position of the 10 Target Points

You are correct. Manual coordinate input of a target point into the PVI-800, then selecting it in operational mode. Turning on the Shkval will slew it to an inaccurate position (accurate at sea level).

 

 

Now, from further testing, it appears manual input references a 2D plane at sea level. It's interesting to note, when you turn on the Shkval without a laser range, it still 'predicts' the camera's LOS intercept with the terrain on the ABRIS. Now, anyone who flies the Ka-50 knows that these predictions can be pretty far from accurate (Once again, because it makes reference to a 2D plane at SL). This can be confirmed since, once uncaged, the Shkval 'prediction' aligns perfectly with a manually input TP on the ABRIS, but the target won't be in sight.

 

Getting a bit speculatory here, but IRL, how difficult would it be to cross reference the aircraft's 3D position, direction and Shkval angular offset with a 3D reference of the area to get an accurate LOS prediction?

 

In any event, this has been interesting. Thanks, again.

[randomTOTEN]

Getting a bit speculatory here, but IRL, how difficult would it be to cross reference the aircraft's 3D position, direction and Shkval angular offset with a 3D reference of the area to get an accurate LOS prediction?

In the A-10C, the 3D reference is called the Digital Terrain System Application Software (DTSAS) and functions basically as you've described it. I suspect other aircraft use a similar system (thinking F/A-18C and F-16C here...)

[Cheetah7798]

If you've ever messed around with the ABRIS in ERBL mode, placing the cursor over any part of the map yields altitude data. So, in a round-about kind of way, the Ka-50 does have access to terrain altitude data. I suppose that it's an entirely different story to have that interact with the PVI-800, though.