Yurgon Posted February 10, 2014 Posted February 10, 2014 I thought TMS-forward long designated SPI? Exactly, and TMS Aft Long sets SPI to Steerpoint. If you want to drop a single JDAM on a markpoint, it doesn't matter so much whether SPI generator is TGP or STPT. But dropping multiple JDAMs in one pass by using markpoints is incredibly fast. Look at my debriefing screenshot - 6 targets destroyed in 10 seconds. I don't think that would be even remotely possible without using markpoints (or steerpoints from a flightplan). The point is, you can't mark targets with TGP as fast as you can toggle steerpoints. So that's the scenario where this seemingly tiny difference has a huge impact. :thumbup:
Yurgon Posted February 10, 2014 Posted February 10, 2014 But still, the GBU 38 is not that accurate. JDAMs are not ideally suited to targets that require precision down to a few meters. JDAM's are not the most accurate weapons in the world, not guaranteed to hit. While all of that is entirely correct to the best of my knowledge, you guys should definitely read "Fire Strike 7/9" by Paul Grahame if you haven't already. :) His JTAC perspective of some of those JDAM drops danger close to friendlies (including himself) is breathtaking.
Supersheep Posted February 10, 2014 Posted February 10, 2014 (edited) Sorry guys, I'm seriously confused now. Is lasing useless (i.e. no effect) or not used because it is not needed in the way it is best/usually employed? I always thought that the videos by ExcessiveHeadspace were common knowledge and the concept presented there makes a lot of sense, at least to me. Then again, post #13 states it is not done. Edited February 10, 2014 by Supersheep Had no coffee yet, apologies. 1 The PVC Pipe Joystick Stand How to thread
kk0425 Posted February 10, 2014 Posted February 10, 2014 Don't mean to derail the thread but how did you get 6 jdams on an A-10? I though it could carry 4 at most.
danilop Posted February 10, 2014 Posted February 10, 2014 (edited) ... Therefore Eddie is correct in that there's normally no need to lase the target when setting the SPI if the TGP is SPI generator by the time of JDAM release and the TGP crosshairs are over the target at that time and the slant angle at that time is high enough that the target coordinates are actually on the intended target. ... Lot of ifs and ands ... Easier to lase (not essential as already stated, ofcourse) to remove some of the additional workload (checking of TGP crosshair before firing the JDAM if not lasing before designating SPI). Sorry guys, I'm seriously confused now. Is lasing useless (i.e. no effect) or not used because it is not needed in the way it is best/usually employed? I always thought that the videos by ExcessiveHeadspace were common knowledge and the concept presented there makes a lot of sense, at least to me. Then again, post #13 states it is not done. It's not useless, but it's not essential as well - if you don't lase, you have to check TGP (SPI) and correct if it's necessary, before releasing the JDAM (very seldom needed). Or you could lase ... Edited February 10, 2014 by danilop
Supersheep Posted February 10, 2014 Posted February 10, 2014 Actually, that post explains a whole lot, I seem to have missed the lines earlier. Thanks for putting it in straightforward terms. The PVC Pipe Joystick Stand How to thread
ZaltysZ Posted February 10, 2014 Posted February 10, 2014 Easier to lase (not essential as already stated, ofcourse) to remove some of the additional workload (checking of TGP crosshair before firing the JDAM if not lasing before designating SPI) from the pilot If you are using area tracing - sure, but if it is in point track mode, TGP will hardly wander away from target, unless you do some crazy maneuver. Wir sehen uns in Walhalla.
danilop Posted February 10, 2014 Posted February 10, 2014 (edited) Just made some screenshots ... (first instant action mission, 3rd waypoint) [ACTIVE PAUSE ON] Designating SPI from a low angle (to be fair, in RL we would never fly this low, hunting for targets to be destroyed by JDAMS). Laser OFF, TGP calculates distance to the target as 8.4 miles in POINT mode: Designating the same target with laser ON, same POINT mode, calculated distance 8.1 miles. Switching the laser OFF, designating POINT as SPI, resuming mission. [ACTIVE PAUSE OFF] Now, we are about 2.5 miles out, it's obvious that we are off (it would be great time to manually correct SPI error now, but for the sake of demonstration we will not do it): Directly above designated SPI without lasing: So, the lasing, although not necessary, has its place if you don't want to correct SPI manually, especially while flying low. In RL applications (means flying high) we probably don't need lasing at all, only minor SPI corrections, from time to time. Another point against lasing in RL - it is obvious to enemy forces :) Edited February 10, 2014 by danilop 1
Maverick-X Posted February 10, 2014 Posted February 10, 2014 Don't mean to derail the thread but how did you get 6 jdams on an A-10? I though it could carry 4 at most. Why shouldn't you be able to? You can load stations 3-9, except #6, so 7-1 = 6. OFC its questionable if you want to load 2 JDAMS instead of 4 Mavericks. (Please ED, simulate burned tires from inner Mav's so these 6 Mav's + 1000 GBU12 loadouts disappear ^^)
Scrim Posted February 10, 2014 Posted February 10, 2014 (edited) Uh... no one ever said it was (at least in this thread)? :confused: The way you described it, you seemed to think something to that effect. You called me out on how the laser worked in conjunction with the TGP and JDAMs when it was you who lacked even a basic understanding of how TGP designated SPIs worked, nitpicking and only acknowledging you were wrong to others won't change that. Sick and tired of people acting like know-it-all's, especially when they're wrong. Edited February 10, 2014 by Scrim
Flagrum Posted February 10, 2014 Posted February 10, 2014 The way you described it, you seemed to think something to that effect. You can ignore the fact that I was right and you were wrong by taking things out of context and pulling straw man arguments, but it won't change anything. Sick and tired of people acting like know-it-all's, especially when they're wrong. I don't get what your problem is. You said, JDAMs don't use laser for guidance, but laser helps to determine the correct slant distance. But on the other hand you claim that the simhq tutorial is bad because it encourages the use of the laser. Then Yurgon illustrated why determining the correct distance is important (or at least, is not a bad habit at all). There was nothing taken out of context!? What context? And what arguments? You both basically said the same!? JDAM = not laser guided but GPS guided to hit a target coordinate. Using laser with JDAM = more precise target coordinate ... but still not laser guided ... --> more precise JDAM.
Eddie Posted February 10, 2014 Posted February 10, 2014 Sorry guys, I'm seriously confused now. Is lasing useless (i.e. no effect) or not used because it is not needed in the way it is best/usually employed? I always thought that the videos by ExcessiveHeadspace were common knowledge and the concept presented there makes a lot of sense, at least to me. Then again, post #13 states it is not done. A LOT of "common knowledge" around here comes from an initial misunderstanding of the mechanics of a system and/or it's intended use. Or to put it another way, there are an awful lot of solutions to problems that don't actually exist. 1
Glamdring Posted February 10, 2014 Posted February 10, 2014 The way I see it is... The non lase method: Set up your initial SPI with TGP and begin attack run. A few seconds before pickle time adjust your TGP to ensure it's on target and set SPI again. Pickle. The lase method: Set up initial SPI with TGP ensuring that laser is on when setting SPI and begin attack run. Pickle. ( using this method I personally would still check the SPI accuracy prior to pickle, but it should be spot on) Either method works, use whichever one you prefer. I imagine that in RL method 1 would be preferred as there is no chance of the laser being detected by the enemy.
Eddie Posted February 10, 2014 Posted February 10, 2014 Just made some screenshots ... (first instant action mission, 3rd waypoint.........................) Even if you did have the laser active throughout that "attack" you'd have the same problem. The only situation in which using the LASER would have helped is if you had made a mark point from your TGP generated SPI at point 1 of your test.
Eddie Posted February 10, 2014 Posted February 10, 2014 The way I see it is... The non lase method: Set up your initial SPI with TGP and begin attack run. A few seconds before pickle time adjust your TGP to ensure it's on target and set SPI again. Pickle. The lase method: Set up initial SPI with TGP ensuring that laser is on when setting SPI and begin attack run. Pickle. ( using this method I personally would still check the SPI accuracy prior to pickle, but it should be spot on) Either method works, use whichever one you prefer. I imagine that in RL method 1 would be preferred as there is no chance of the laser being detected by the enemy. And that is the misunderstanding I referred to yesterday. A SPI is NOT a fixed point, it is a constantly updated position taken in real time from which ever sensor you have set as the SPI generator. In you example above, you point the TGP at a target and get position A which is looking at the terrain "through" the target, then you fire the LASER and you set the SPI with your LASER on and it gives you position B as your SPI location, now this is where you think it stops yes? Wrong, the second you turn the LASER off the SPI will update to position A once again.
danilop Posted February 10, 2014 Posted February 10, 2014 Even if you did have the laser active throughout that "attack" you'd have the same problem. The only situation in which using the LASER would have helped is if you had made a mark point from your TGP generated SPI at point 1 of your test. Laser is needed only before designating SPI in that example, not throughout "attack". If you lase prior to designation, you get different distance than without lasing. SPI is in different place. Try it. :)
Supersheep Posted February 10, 2014 Posted February 10, 2014 (edited) Assume the TGP is SOI, and a GBU 31 is selected. Now, is the SPI generated when I mash TMS UP or when the pickle buttom is pressed? This thread has both concepts in it. EDIT: I got sniped, hard. Edited February 10, 2014 by Supersheep The PVC Pipe Joystick Stand How to thread
Flagrum Posted February 10, 2014 Posted February 10, 2014 And that is the misunderstanding I referred to yesterday. A SPI is NOT a fixed point, it is a constantly updated position taken in real time from which ever sensor you have set as the SPI generator. In you example above, you point the TGP at a target and get position A which is looking at the terrain "through" the target, then you fire the LASER and you set the SPI with your LASER on and it gives you position B as your SPI location, now this is where you think it stops yes? Wrong, the second you turn the LASER off the SPI will update to position A once again. Iirc, the target coordinates are tranferred to the weapon at release, right? So you would have to lase just for one or two seconds while releasing the JDAM.
Eddie Posted February 10, 2014 Posted February 10, 2014 Iirc, the target coordinates are tranferred to the weapon at release, right? So you would have to lase just for one or two seconds while releasing the JDAM. The coordinates are transferred when you press the pickle button, then repeated back by the weapon for confirmation, and then the weapon is released. So yes, if you had the LASER firing when the pickle button was pressed then, of course it would be those coordinates that are passed to the weapon because that is your SPI.
Eddie Posted February 10, 2014 Posted February 10, 2014 Laser is needed only before designating SPI in that example, not throughout "attack". If you lase prior to designation, you get different distance than without lasing. SPI is in different place. Try it. :) http://forums.eagle.ru/showpost.php?p=1992503&postcount=40 Read it, think about it, absorb it. You're suffering from the same, apparently common, misunderstanding. And there was me thinking that the SPI concept was simple. :huh:
Supersheep Posted February 10, 2014 Posted February 10, 2014 From the DCS Man: A SPI is a 3D point in space that the systems use as a shared reference location to cue weapons, aim sensors and send over the datalink. This is a key component of the A-10C and helps you to locate targets with onboard sensors (Targeting Pod, Tactical Awareness Page, HUD, Maverick and AIM-9), then cue weapons and slave sensors to it. The default SPI is the steerpoint. Once a sensor has been set as the Sensor Of Interest (SOI), the sensor may designate the SPI. Once a SPI has been defined, the SOI can change without changing the SPI. The current SPI generator is always indicated in the lower left corner of the HUD. The system is always tracking a SPI with the current steerpoint being the default SPI (such as when the aircraft is powered). The exception is if the SPI is commanded to steerpoint but there is no valid steerpoint because the CDU is not available. English is only my third language, but I read that as to indicate something different from what you say. Assuming that everyone has read and understood the manual, that might be where the common knowledge comes from. Thinking about it, the way you explained it actually makes a lot of sense. The PVC Pipe Joystick Stand How to thread
Supersheep Posted February 10, 2014 Posted February 10, 2014 Addendum: Try making the IFFCC the SPI, slave all to it, yank on the stick and watch what the TGP. That's only possible with the concept presented in post #40. The PVC Pipe Joystick Stand How to thread
Eddie Posted February 10, 2014 Posted February 10, 2014 From the DCS Man:......... That says exactly the same thing. However as it does not clearly state the SPI is a constantly updated point, it could be misunderstood.
Supersheep Posted February 10, 2014 Posted February 10, 2014 Apparently, I did, at least. The PVC Pipe Joystick Stand How to thread
danilop Posted February 10, 2014 Posted February 10, 2014 (edited) http://forums.eagle.ru/showpost.php?p=1992503&postcount=40 Read it, think about it, absorb it. You're suffering from the same, apparently common, misunderstanding. And there was me thinking that the SPI concept was simple. :huh: I understand that. I'm alright, thank you for caring for my suffering and well-being. :) I was talking about measured distance (I think it's obvious in my post, probably, the only missing part is "and firing" after "If you lase prior to designation" ). If you'd cared to read all my posts from this thread it should be obvious. Edited February 10, 2014 by danilop
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