Change Wording: "Set SPI Generator" instead of "Make SPI"

The LOS is NOT imaginary! As Shagrat explained to you, it ends at a specifically calculated point on the ground!! It is calculated using INS GPS, gimbals among other critical components.

 

 

Can you guess what that point on the ground is called??

It is imaginery as it is not a visible line (unless you put on NVGs and activate the IR pointer). It's still a line and not a point anyways.

It is imaginery as it is not a visible line (unless you put on NVGs and activate the IR pointer).

 

 

and neither is the HUD TDC a real box in 3D space. IT can however be the SPI!

What does that have to do with changing Waypoints?????

I was talking about the waypoints stored in the memory of the CDU of each aircraft. If I change the coordinates of waypoint 5 in my CDU it will still be waypoint 5, just at a new position.

and neither is the HUD TDC a real box in 3D space. IT can however be the SPI!

The position at the end of the TDC's LOS can be the SPI. The TDC itself can only be a SOI.

The LOS is NOT imaginary! As Shagrat explained to you, it ends at a specifically calculated point on the ground!! It is calculated using INS GPS, gimbals among other critical components.

 

 

Can you guess what that point on the ground is called??

Technically the LOS just extends from the sensor until it intersects with any object. If there is a building in front of the SPI on the ground, technically the LOS ends at the building, as the SPI is "not in sight"... but that is deliberate nitpicking. We all know what "LOS designates the SPI" means in this context. ;)
Edited September 13, 2019 by shagrat

I was talking about the waypoints stored in the memory of the CDU of each aircraft. If I change the coordinates of waypoint 5 in my CDU it will still be waypoint 5, just at a new position.

 

 

 

 

That's not what I asked.

 

 

 

If 2 planes fly with the same WP entered, but mid flight one changes the WP coordinates, do you still say they are the same waypoints??

Technically the LOS just extends from the sensor until it intersects with any object. If there is a building in front of the SPI on the ground, technically the LOS ends at the building, as the SPI is "not in sight"...

Even if I use the laser for ranging? Shouldn't the SPI then be on the building instead of behind it?

The position at the end of the TDC's LOS can be the SPI. The TDC itself can only be a SOI.

Technically correct, but again. We all know how the LOS designation of the SPI works with TDC/MAV/TGP... this is not helpful.

That's not what I asked.

 

 

 

If 2 planes fly with the same WP entered, but mid flight one changes the WP coordinates, do you still say they are the same waypoints??

They are never the same waypoints system wise. A waypoint stored in the CDU of one plane is a different waypoint than the one stored in the CDU of another aircraft, regardless of themhaving the same waypoint number and coordinates or not. They are two different objects of bits and bytes in two different computer systems of two different planes.

That's not what I asked.

 

 

 

If 2 planes fly with the same WP entered, but mid flight one changes the WP coordinates, do you still say they are the same waypoints??

No, of course not, but this is not relevant for the SPI discussion. We hopefully understand, a SPI can be assigned to the Steerpoint and that a steerpoint can be any waypoint or markpoint etc. and that we can easily change waypoint coordinates and thus the Steerpoint with it.

EDIT we need to slow down, guys, I have trouble to correct the autocorrection of my smartphone at this pace... :D

Edited September 13, 2019 by shagrat

Technically correct, but again. We all know how the LOS designation of the SPI works with TDC/MAV/TGP... this is not helpful.

Agreed :)

Even if I use the laser for ranging? Shouldn't the SPI then be on the building instead of behind it?

Yep, as it then uses the laser returns distance and no longer the LOS... ;)

 

EDIT I'll detail this in german: in der Geometrie wäre die LOS eine Gerade, die den Boden schneidet. Der Laser Range Finder misst die Strecke zwischen zwei Punkten... ich weiß, Klugscheißerei ;)

Edited September 13, 2019 by shagrat

Yep, as it then uses the laser returns distance and no longer the LOS... ;)

The laser returns the position at the end of the LOS as well as its distance.

The laser returns the position at the end of the LOS as well as its distance.

Actually it measures the time for the reflected light to reach the TGP again and calculates the distance, while still the GPS position, heading the sensor looks and angle provide the details to calculate the point. It simply replaces the line intersecting the groundplane with the exact distance from the TGP. ;)

I'llgive an example on LOS and how it works in relation to the TGP and how it generates (creates) the SPI (I've worked on surveillance UAVs using similar technology).

 

 

Whether TGP uses Digital Terrain Elevation Data (DTED) or any other format, It can do this:

 

 

 

 

1 Slew the TGP, ) and zoom it in while the glass on the pod is covered by a piece of paper (so you can't actually see what it's actually looking at).

 

 

 

2 Do TMD FWD LONG (Set/make/generate SPI)

 

 

3 Do China Hat forward long (Slave all to SPI)

 

 

4 Look at the MAV screen

 

 

 

5 Take the paper off the the glass

 

 

 

The TGP and MAV will both be looking at the exact same spot!!!

Edited September 13, 2019 by Dagger71

Actually it measures the time for the reflected light to reach the TGP again and calculates the distance, while still the GPS position, heading the sensor looks and angle provide the details to calculate the point. It simply replaces the line intersecting the groundplane with the exact distance from the TGP. ;)

 

 

Bingo!!

True, it should rather say "shift SPI to new position" instead of "make SPI on new position" in my previous comment which only was an attempt to make sense of what LJQCN101 said. :)

 

I was also in an attempt to make sense of what the DoD manual said, though I do find some occurrence when it said "TGP is SPI" which is also not good for understanding. :lol:

 

Anyways I don't have a preference as long as it can be explained in a paragraph (or more).

I was also in an attempt to make sense of what the DoD manual said, though I do find some occurrence when it said "TGP is SPI" which is also not good for understanding. :lol:

 

Anyways I don't have a preference as long as it can be explained in a paragraph (or more).

 

 

 

 

It's referring to the TGP LOS that is SPI.

 

 

 

Think of it as a laser pen. I can point it a wall and generate (make a SPI).

 

 

 

Its not really the Pen that's the SPI, but the end of the LOS that is. But If I am using a laser pen, eyeglasses that emit a laser and a laser clipped on my shoulder, it's easier to say "The pen is now SPI" instead of the dot created by my pen is now SPI.

As the Steerpoint SPI, it will never change or update unless you change to another steerpoint. Just as with a TGP LOS SPI, it will not change or update unless you slew it or select another SPI (from either another SOI or any of the 3 other ways to obtain a SPI).

 

Jeez, I need to take a vacation from vacation in order to keep up with you guys. :D

 

First, the obvious. A line of sight is a line, and a line is not a point, so it doesn't help to explain that LOS is SPI. For someone who deeply cares about the most minute details, it's fascinating that you keep inventing descriptions that make no sense whatsoever, and then argue for 3 pages in a row that everyone else is wrong.

 

But the more important part is this.

 

Make SPI on TGP (obviously not my preferred choice of words, but I think we all know which HOTAS action I'm referring to).

 

Set TGP to Point Track mode, slew it on a moving ground vehicle that it can track.

 

Where's the SPI in that very moment? Where's the SPI 5 seconds later? A minute later? While the TGP keeps tracking the ground vehicle, does the SPI remain at the position the TGP was last slewed to?

 

What happens if you select another SOI during that time?

 

Good point! Let me rephrase my previous post then:

 

If you change the coordinates of a waypoint in the CDU it will still remain the same waypoint (Waypoint A) and not become a new waypoint (Waypoint B), but it will shift to a new position and so will the SPI.

 

I fully agree, and that is a great example of how the system works (when STPT is SPI Generator and that waypoint set as steerpoint, obviously). :thumbup:

I was also in an attempt to make sense of what the DoD manual said, though I do find some occurrence when it said "TGP is SPI" which is also not good for understanding.

 

 

 

Anyways I don't have a preference as long as it can be explained in a paragraph (or more).

That's basically the original problem.

We have a quite comprehensible chapter on the SPI later in the manual. The first mention of TMS forward long is in the Controls overview, which has only one line for the TMS action: currently reading "Make SPI". Real life Pilots have the luxury of a classroom training by an experienced Trainer explaining the concept in detail, like we had here over the last 140 posts.

Since the DCS: A-10C Beta 10 years ago this troublesome wording causes misunderstanding.

The discussion derailed as some posters didn't consider that the DCS manual is not a 1 to 1 copy of the Air Force manual and the intention of a Game manual is to suffice as a self training ressource instead of following the real life manual to the letter.

With the lack of Classroom training for newcomers it is very common to misinterpret the "Make SPI" wording.

All Yurgon asked, was to find a way to represent the actual function of "TMS forward long" better in the controls overview so it can't be misunderstood as "Create a targetpoint and store it" what often happened and caused a lot of confusion.

"Set SOI as SPI designator" would be consistent with the SPI chapter, it would reference the SOI as source for the coordinates, and finally isn't easily misunderstood as saving a point coordinate in a database or similar.

I don't care that the wording will be different from the Air Force manual, as whoever has legal access to it is still allowed to use it instead of the DCS manual, but as a Military Flight Sim developer ED should care about the customers outside the US as well, who only have access to the Manual coming with the product.

This isn't even a major change, just a basic optimization in wording to make it easier to understand.

Jeez, I need to take a vacation from vacation in order to keep up with you guys. :D

 

First, the obvious. A line of sight is a line, and a line is not a point, so it doesn't help to explain that LOS is SPI. For someone who deeply cares about the most minute details, it's fascinating that you keep inventing descriptions that make no sense whatsoever, and then argue for 3 pages in a row that everyone else is wrong.

 

 

 

 

I didn't invent anything. Even Shagrat knows this now. Did you look at page 400 of the manual?

 

 

 

It is also in DoD manual.

 

 

 

So the line of sight is technically an unobstructed line between two points. Draw it from the center of the TGP cross hairs to the ground that it is point at. That point on the ground represents the SPI.

 

 

 

Do you understand my laser pen example? I think that might be the easiest way to understand.

 

 

 

The SPI always remains with the sensor that is generating (making) it. If is HUD SOI that could be the middle of the TDC or a CCIP, depending on submodes used.

and finally isn't easily misunderstood as saving a point coordinate in a database or similar.

 

 

But the SPI IS in fact a saved 3d point "in a database or similar."

 

 

 

When TGP is SOI and not generating (making SPI), nothing you do with it is recorded on any level.

 

 

 

The moment you do TMS FWD LONG, onboard sensors and processors create the SPI ( a large amount of calculations in a microseconds) that the LOS points to on the ground. When the TGP slews, those calculations are redone and continue to get done until you stop moving the SPI, then it remains a saved point. Like mentioned before it is a snapshot.

 

 

 

 

 

Remember what I mentioned about the TGP pod glass aperture could be covered up in black tape and it will still be precise since the lightening pod nor any sensor does not actually use the video to generate the SPI. It is there for visual cue.

 

 

 

When switching from say TGP LOS SPI generator to the HUD TDC as SPI, it is actually a NEW and completely different set of calculations used to determine the SPI.

 

 

 

 

 

This calculation of SPI is not something that even could have existed 40 years ago.

Edited September 13, 2019 by Dagger71

Here is another interesting fact.

 

 

 

If you take an A10C operating out of Afghanistan and fly it in a remote Island of Antarctica you will NOT be able to generate (create) a SPI because it will be missing vital DTS, data and map package information.

I didn't invent anything. Even Shagrat knows this now. Did you look at page 400 of the manual?

 

The concept (TGP LOS, ground intersection) is pretty clear, there's nothing wrong with that, and the idea of putting an obstruction in front of the TGP sounds like a good thought experiment in order to realize that it's all about measuring angles (caveat: unless the laser is firing - another great thought experiment).

 

I believe no one in this thread ever said otherwise. I believe Shagrat knew this before you even purchased the A-10C.

 

It's just that "TGP LOS SPI" seems like a pretty weird way of putting it to begin with. Introducing this after about 100 posts of back and forth discussion and then defending it just seems... unnecessary. It just spawns more discussion and does exactly nothing to clarify anything. Insinuating that others don't understand the idea behind it when the discussion is about your choice of words... just be aware that saying out loud what I think about *that* would be a very, very clear 1.2 violation.

 

Anyway, you argued repeatedly the TGP as SPI Generator will never change the SPI unless it is slewed:

 

When the TGP slews, those calculations are redone and continue to get done until you stop moving the SPI, then it remains a saved point. Like mentioned before it is a snapshot.

 

So could you please clarify what happens to the SPI when the TGP is SPI Generator, is in point track mode, and is tracking a moving object? This may sound like nitpicking, but may well turn out to be at the very core of the debate.

Edited September 13, 2019 by Yurgon
Quote for clarification and documentation

So could you please clarify what happens to the SPI when the TGP is SPI Generator, is in point track mode, and is tracking a moving object? This may sound like nitpicking, but may well turn out to be at the very core of the debate.

 

 

 

 

Yes absolutely. this is much better to ask questions then to make unsubstantiated claims.

 

 

 

 

 

The TGP tracks the moving vehicle through several methods, might be using Gaussian mixture mode, which uses the camera sensor to detect differences in contrast, pixels and other criteria and uses calculations to determine if this object is indeed moving or is just background noise.

 

 

 

So when the TGP is in track mode (think of it as auto-slewing) the SPI is not really looking at the vehicle, but through it to the spot on the ground that it calculated through the center of the LOS as discussed before. As the vehicle moves, the LOS moves, therefore a new SPI calculation is made. The margin of error between the actual SPI location and the center of the track point (vehicle) is completely negligible when it comes to using conventional bombs. Not to mention using the laser to get a more accurate SPI

 

 

 

It is possible newer versions of airborne surveillance can also implement some sort of instant volumetric calculation to get a more precise point, but I am unaware of such. Volumetric calculations take time and lots of data to be processed, usually taking a few days just to map up a small area of land.

Edited September 13, 2019 by Dagger71