SPI indication and slave MAV to TGP

[fael097]

can someone point me what section on the manual explains better SPI? or even explain, cuz i'm never sure what's my current SPI, if it's the target i defined or what, sometimes there are 3 indications on my hud, idk, confusing.

 

also wanted to know how to slave the mav tracker to my TGP target. the mav camera wont zoom in, so it's pretty useless compared to the TGP imho.

 

thanks in advance

[112th_Rossi]

The current SPI is the diamond/square indicator with a line coming out of it.

 

To get the Mav to slew to the current SPI, push TMS Forward Long, then TMS Forward Short to lock. The Mav has a one stage zoom function.

[sonic]

To get the Mav to slew to the current SPI, push china hat Forward Long, then TMS Forward Short to lock. The Mav has a one stage zoom function.

 

FYP :smartass:

[112th_Rossi]

Correct. Doh!

[miguelaco]

Also, lower left part of the HUD indicates your SPI source at all times.

[nomdeplume]

You might find this video informative: http://www.youtube.com/watch?v=AX9noFmlQNI

(don't forget you can pause it if the captions come too quickly)

 

To slave the Maverick to any sensor (including the TGP), you need to make that sensor your SPI, and then use 'china hat fwd long' to slave all your other sensors to your SPI. The video slaves the Maverick seeker to the steerpoint and to the HUD TDC, but if can follow the video you should be able to apply it to the TGP just as easily.

 

Also worth noting that the 'china hat aft long' function to slave the TGP to your steerpoint works regardless of what the SPI is, and can be done while the TGP is the SPI. So, you can use mark points to get your TGP pointing near your targets (that you've already marked), and then slave the Maverick to the TGP, and use the TGP to refine the aim. Then switch to the Maverick for an easy lock-on.

[fael097]

thanks! very informative guys, i really appreciate

[Crescendo]

The SPI is your current Sensor Point of Interest.

 

Think of the SPI as a point in three dimensional space. In other words, it is literally a very specific location somewhere in the world, be it in the air or on the ground, or anywhere in between. The SPI, a point in three dimensional space, serves as a reference location that can be used to tell sensors and weapons where to look. It can also be shared with other military assets over the Datalink (your wingman for example).

 

The SPI can be defined by any of the sensors on the aircraft. For example, the TGP can be 'set as SPI', so therefore whatever the TGP is 'looking at' is your current SPI. Similarly, the Target Designation Cue (TDC) on the HUD can be 'set as SPI', so therefore whatever point you slew the TDC to will be your current SPI.

 

Your aircraft always has a SPI, and it is shown in the lower-left corner of the HUD. By default, the SPI will be the currently selected waypoint, i.e. the steerpoint (STPT). This means that when you first power up the aircraft, the SPI will be your steerpoint. If you look in the lower-left corner of the HUD, you will see the text "STPT". This text indicates that the current SPI is defined by the steerpoint. Likewise, if you look in the lower-left corner of the HUD and see the text "TGP", this means that the current SPI is defined as whatever the TGP is currently' looking at'.

 

To define the SPI as something other than the currently selected STPT, you use the command TMS FWD Long (TMS FWD L). For example, if I am looking at target with the TGP and I want to set that target as SPI, I would set the TGP as Sensor of Interest (SOI), and then hold TMS FWD L. This would set the TGP as SPI, and so therefore whatever the TGP is 'looking at' is now the SPI (in this case the target). As soon as you use the TMS FWD L command with the TGP set as SOI, the text in the lower-left corner of the HUD will change from "STPT" to "TGP". This is because you have 'told' the aircraft to use the TGP as SPI rather than the default STPT. However, if you decide that you no longer wish to use the TGP as SPI, you can use the command TMS AFT L to reset the SPI to STPT. TMS AFT L will always reset the SPI back to STPT (the default SPI), no matter what the current SPI is (TGP, MAV, TDC etc.)

 

As alluded to in the second paragraph, the reason why the SPI is so useful is that it can be used to 'tell' the sensors onboard the aircraft 'where to look'. For example, consider yourself flying in one of the easy quickstart missions. When you first take control of the aircraft, the SPI will be set to the default SPI, i.e. STPT. This means that your SPI is whatever STPT you currently have selected. If you have waypoint 2 (WP2) set as your STPT, this means that the point in three dimensional space represented by WP2 is your current SPI. In the case of the easy quickstart missions, there are two soft-skinned trucks sitting very close to WP2. Because your currently selected STPT (WP2) is very close to the trucks, this means that your SPI is also very close to the trucks (your STPT is the SPI by default).

 

What this means is that you can 'tell' the aircraft's sensors to 'look at' the SPI, and by doing so, the sensors will be 'looking at' a point in space near to the trucks. For example, I know that there are trucks near WP2, so I set WP2 as my STPT. By default, the STPT is set as the SPI. Knowing this, I can use the command CHINA HAT FWD Long (CH FWD L), to 'slave' all of the aircraft's sensors to the current SPI. ("Slave" is a shorthand way of saying that something is being "forced to move" to a certain position.) After pressing CH FWD L, all of the aircraft's sensors will be 'slaved' to the SPI (remember that the SPI is the STPT, which is WP2). The TGP, MAV cameras, and TDC are all sensors, so this means that they are all now 'looking at' the current SPI (STPT, WP2, where the trucks are). Great! If I now bring up the TGP on one of the MFCDs, it will be 'looking at' the SPI (STPT, WP2) and I should hopefully see the trucks.

 

However, the TGP will probably be 'looking at' at a patch of ground (the STPT, wherever the three dimensional point represented by WP2 happens to be), and I certainly don't want to shoot at that! So, I set the TGP as SOI, slew the tracking gates over one of the trucks, initiate a point track with TMS FWD Short (TMS FWD S), and then press TMS FWD L. TMS FWD L sets the current SOI as SPI. Therefore, with the TGP as SOI, CH FWD L will 'set the TGP as SPI', and so whatever the TGP is 'looking at' is now the current SPI. If you look at the lower-left corner of the HUD, the text will have changed from "STPT" to "TGP", meaning that the aircraft is now using whatever the TGP is 'looking at' as its SPI. In this case the TGP is looking at a truck.

 

The targeted truck is now SPI, so to speak. Perfect!

 

So, I now have a truck 'set as' SPI. If I want a Maverick to 'look at' that truck, all I have to do is press CH FWD L (slave all to SPI). CH FWD L 'forces' the Maverick camera (and all other sensors on the aircraft - TGP, TDC etc.) to 'look at' the current SPI. Because the TGP is the current SPI, the Maverick camera slaves exactly to where the TGP is 'looking', i.e the targeted truck. (As an aside, the TGP will not move even though CH FWD L slaves ALL sensors, including the TGP, to the SPI - this is because the TGP is already the SPI and therefore it doesn't need to move.) I can now bring up the MAV page on an MFCD, and the MAV tracking gates will be slaved to the SPI (the SPI being the TGP 'looking at' the truck). To kill the truck with a Maverick all I have to do is set MAV as SOI, press TMS FWD S to attempt a lock with the tracking gates, and then, once a successful lock has been initiated, launch the Maverick by pressing Weapon Release.

 

Finally, if I decide that I no longer wish the TGP to be SPI, I can press TMS AFT L (with any SOI) to reset the SPI back to STPT.

 

So, that's a rough 101 primer to what the SPI is. Remember that you can set the SPI with any of the sensors onboard the aircraft (TAD, TGP, TDC, MAV), but no matter what, the unique SPI with will always appear in the lower-left corner of the HUD. If you find that you've stuffed up somehow, reset the SPI to STPT with TMS AFT L and start over.

 

There is of course more to learn of course (especially the unique functionality of CH AFT L), but nomdeplume's post should help you out with that.

Edited May 3, 2011 by Crescendo
Fixed grammatical errors.

[AlphaOneSix]

As mentioned, "SPI" is the Sensor Point of Interest and is a point in space somewhere. However, it is NOT a sensor itself. In other words, you can't "set TGP as SPI". Instead, you set TGP as SOI (Sensor Of Interest). The TMS FWD LONG command doesn't set a sensor as SPI, it uses what the current SOI is pointed at to make a new SPI.

 

Still beyond that nitpicking, a lot of good info in this thread.

[Crescendo]

As mentioned, "SPI" is the Sensor Point of Interest and is a point in space somewhere. However, it is NOT a sensor itself. In other words, you can't "set TGP as SPI". Instead, you set TGP as SOI (Sensor Of Interest). The TMS FWD LONG command doesn't set a sensor as SPI, it uses what the current SOI is pointed at to make a new SPI.

 

Still beyond that nitpicking, a lot of good info in this thread.

 

Your are right of course, AlphaOneSix.

 

That's why I always write " 'set as' " where I can. I use the single quotation marks (scare quotes) to indicate that the phrase is not literally correct. I just find it easier to think that way. I should have mentioned this, but you've done a more than adequate job of explaining.

 

Nothing wrong with nitpicking, by the way. :thumbup:

[Frederf]

We could really use some language to describe a sensor's "point that will become SPI if that sensor is chosen to source the SPI but still called this even if this sensor is not currently chosen to source the SPI." There's got to be a term for that.

 

It's fast to say "make TGP SPI" but like A16 says it's not exactly accurate. "Make TGP POI the SPI" would be better if POI meant that long-winded thing above.

[Crescendo]

"Make TGP POI the SPI" would be better if POI meant that long-winded thing above.

 

"Make (sensor) POI the SPI" is a pretty decent way of saying it. Perhaps "Make the (sensor)'s POI the SPI)" would communicate the idea even clearer for a lay audience. I might start using either of these in the future.

 

I wonder what technical language the USAF uses when it trains its pilots, and what the pilots themselves actually say when talking informally.