The Pointing Cross and Crosshairs in Maverick WPN Display
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Manual says, “The displacement of the pointing cross from the center of the display shows the relative bearing between the LOS of the missile seeker and the longitudinal axis of the missile.”
I assume the pointing cross represents the missile’s axis?
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The center of the display represents the longitudinal axis of the missile, and the pointing cross represents the LOS of the missile seeker. Perhaps text that could be improved.
In short, if you are looking left, the pointing cross will be on the left of the display. If you look right, the pointing cross will move right.
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The center of the display represents the longitudinal axis of the missile, and the pointing cross represents the LOS of the missile seeker. Perhaps text that could be improved.
In short, if you are looking left, the pointing cross will be on the left of the display. If you look right, the pointing cross will move right.
But isn’t strange that the slewable crosshairs represent the missile’s axis? I would have thought the axis stays fix while you slew the crosshairs around it.
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…. I would have thought the axis stays fix while you slew the crosshairs around it.
Isn’t that what this says:
The center of the display represents the longitudinal axis of the missile, and the pointing cross represents the LOS of the missile seeker. ……
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There is two ways they could have decided on doing this. They went with this way over the other. Personally I think this is a little more intuitive in use than the other way. The other way is perhaps a little easier to think about, but in use I image slightly more confusing. Perhaps others disagree. shrugs
Its a motif that stays constant across other systems in the jet, so perhaps there existed already a convention that the missile designers just kept to. The dot in the TGP display works the same way, for example. Its position on the display tells you where the seeker is looking, relative to the missile body.
In fairness, the center of the display does stay fixed, as the missiles axis does. The pointing cross does slew around the center of the display, as the seeker does. The only issue with doing it the way it works, is that it means the center of the display is the view of the seeker, and represents the missile axis rather than the seeker FOV center.
The good thing is, in use it is intuitive. Watch the cross move around as you move the jet and as you slew the FOV, and it will make sense real quick.
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I did some slewing around and looking. What I noticed is that the HUD Mav LOS is always at where the WPN Crosshairs are at. The pointing cross and crosshairs also line up when slewing reaches the centre of the HUD. I think I need to look at an actual AGM-65 head to understand how it works. I may be getting the terms confused. Missile axis doesn’t quite fit since it is perpetually forward on the rail and also depends on which rail or wing the missile is on.
Update 2: Ok, so the IR seeker camera is obviously slewable in the Mav head (pics). Let’s see if I can make sense of this. The crosshairs/WPN display is simply what the camera sees and locks on in the camera’s (slewed) axis or LOS. Hence, the HUD Mav LOS circle is always on the same spot (if boresighted) as the WPN crosshairs. The pointing cross merely represents a ‘symbolic’ position of the slewed camera’s axis from the longitudinal axis of the missile, being also ‘symbolically’ represented by the WPN crosshairs. In other words, these two axes are not literal physical axes when considering their relative positions to each other.
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Almost spot on, but the HUD circle does not always line up perfectly with where the seeker is pointing, because the missile is generally not pointed perfectly dead ahead due to mounting misalignment. It is pretty close if you boresight first.
Also, they are literal axes, in a cartesian representation of the seeker position.
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since we are for needles in the sand…
The wpn camera, if I could shake the whole missile (which g forces do pretty well) would bounce or stay steady not moving at all? This has 2 sub questions:
a. wpn Off
b. wpn OnNow regardless on off, probably when powerd on the camera tries to find a center to point to, by it’s logic. Thus we do the alignment or ground stabilize with the TGP sequence?
If no TGP available then you do it with radar with a known target? So you align it (Radar or TGP) power off and it keeps the stabilization right? -
it stabilises with gyros and image processing. It boresights with TGP (if MBC equipped) or the HUD (VIS mode).
If the missile shakes (say from turbulence) the weapon cam should stay reasonably steady on the fixed point on the ground.
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Almost spot on, but the HUD circle does not always line up perfectly with where the seeker is pointing, because the missile is generally not pointed perfectly dead ahead due to mounting misalignment. It is pretty close if you boresight first.
Also, they are literal axes, in a cartesian representation of the seeker position.
Oh yes, thanks, I forgot about the boresighting.