You'll have my results soon, poseurt2.

Herald

Regarding the real range the the Abrams LRF , it is certainly not 9km ! You already have to be carefull when you lase at 3000m because you can get multiple returns , at 3800m you sometimes have to lase 3 or 4 times to get a proper reading .
(From the Abrams Gunner Guide) :

""THE ART OF LASING
As stated in the previous tutorial, the laser rangefinder (LRF) works by sending out a pulse of laser light, and using the return times of the reflections to calculate the range. Note that there may be more than one return time to measure because of multiple reflections. Although the pulse of laser light is a focused beam, this beam does widen over distance. At a range of two or three kilometers, the beam will be spread out so much that a tank might NOT block the entire beam. In this case, some laser light might be reflected off the ground well in front of the target, and some may be reflected off the ground or trees well behind the target.
When the LRF receives multiple returns, a bar appears over the range display numbers in the GPS. The gunner must then decide whether the displayed range is valid. The displayed range will be based on either the FIRST return or the LAST
return, depending on the setting of the RANGE SWITCH (at the time the target was lased).

How should the gunner set the range switch?
If the target is big enough to block the entire laser beam, the range switch should be set to LAST RETURN. The width of
the laser beam will be about half as wide as the circle in the GPS reticle, so use that as a guide to determine if the beam should be entirely blocked by the target. Be careful with targets that have spaces in them, like wheeled vehicles, since the beam may pass through these spaces. FIRST RETURN should be used when there are no obstacles between your tank and the target, especially for distant targets that cannot block the entire beam.

The gunner should also choose where he lases the target based on the range switch setting. If LAST RETURN is selected, he might want to lase a little low so the beam does not spill over the top of the target and reflect off the distant landscape. If FIRST RETURN is used, then the gunner might want to lase a little high, so that the beam does not reflect off the ground in front of the target. In both cases, the gunner should aim at the center of the target when actually firing the gun.""

I hope things are clearer and easier to understand . This is not a singularity of the Abrams , all Tanks have these limitations , but some Tanks less than others . I know for a fact that Leopard 2A4s and over (A5s and A6s) and Leclerc have a slightly better system . Russians LRFs are good too because they need it to get good firing solution at up to 5500m for their Reflex Missiles .

Cheers .

(BW, watch me be fair.)

Herald, while I am not taking sides, I think BW is putting up a pretty good fight.  I think the issues are becoming clarified by these claims and counterclaims, and would do so with or without abuse.  You may certainly learn otherwise from your tanker friends, but what he is saying makes a certain amount of sense.  I think you are a little quick to jump down his throat. 

Have you read much H. Beam Piper?  In his book Space Viking, he offerd a very useful piece of life advice.  When somebody says something that sounds completely off the wall, don't tell him he's crazy; ask him, What are you talking about?

I know, I know, the blague is often wearisome, but he COULD be correct.

Nichevo to Herald :
""You may certainly learn otherwise from your tanker friends""

No , he will not .
(Btw , there is a way to get ranges over 4000m but it doesn 't work everytime . It is in fact accidental but the gunner can take advantage of it but as I said , it only happens from time to time . Anyway a good gunner can only use the "glitch" to fire at a static target as the FCS can 't compute a lead at over 4000m . Remember that what I say cannot be taken into account as a Capability or a Tactic : it happens randomly and not often) .

""but he COULD be correct""

I am :-)

Cheers .

While I 'm on the Abrams very few weaknesses , it might be interesting to raise a point which should be taken into account by the US MoD .
A lot of US Tankers (TCs and Gunners) are sometimes complaining that the Abrams LRF can burn out too quickly .
I agree !
Exemple : One has to understand that when you 're a Tank gunner in a fight other than in the desert , you can sometimes have to deal with the vegetation . That 's sounds irrelevant but it isn 't , a simple bush 1.5m high 400m in front of the target can screw-up your range and if you 're using Lase-Blaze , you 'll end up short . So , you sometimes need to re-lase because you 're just unsure that the range is good and if the target is on the move the must re-lase every one second to keep the FCS computer updated for the added lead . Sometimes , you just burn the laser because you "lased" too many times within a very short amount of time . As a gunner , this is nightmare scenario :-(
You need to go Manual to estimate both range and lead ! You can still manage if you know your station well and if you 're a good and fast gunner , but it 's not easy .

Indeed , the Abrams LRF can go Out Of Order :
(From the Abrams Gunner Guide) :
"WARNING! The laser in the M1's LRF can burn out if you overuse it, so be careful!
To be safe, never fire more than four pulses in an 8-second period. Don't hold the lase button down for a long time. If you see a green F next to the range numbers in the GPS and the red reticle disappears, you have burned out the LRF."

On the other hand , the Leopard 2A4 has a much safer system :
"Unlike the Abrams M1, the laser in the Leopard's LRF can NOT burn out if you overuse it, but it will shut down temporarily. To be safe, don't fire the laser more often than once per ten seconds. Occasional immediate re-lasing is OK, though. Don't hold the lase button down for a long time."

The Leopard 2A5 has a rather similar system to the one used on the Leclerc :
""the laser in the Leopard 2A5's LRF can NOT burn out if you overuse it, but it will shut down temporarily.
Normal output for the LRF is 1 pulse each 6 seconds.
Max output for the LRF is 3 pulses in a 2-second interval, followed by an 11-second break, before the LRF is functional again."

You really need to be a Tanker to understand the crap behind a LRF who can burn out ! In the middle of a heavy and busy battlefield , you need to lase and blaze as kick as you can because it is target rich on both sides and you do not want to die . It is why a good LRF and a good Autoloader can save your life , this combo can fight longer and faster while allowing yourself to be on the move ~and fast~ constantly .

You see that if you add :
1) above average armor
2) decent but not brilliant LRF
3) good but not excellent FCS
4) Thirsty engine
5) hot signature engine
6) excellent gun
7) best ammo around
What you get is an Abrams .
They are better Tanks around .

Cheers .

1. BEAM scatter depends on weather, particulate smoke,  the actual  reflectivity of obscuring ground and how much albedo the actual tank that reflects the laser has.
2. US average tank fleet FCS considers that in the range solution sets by using a MEAN solution.. German FCS systems are different in that these average all results before presenting a final solution. The British adopted this approach with the same exact CDC computer software they integrated. The US system selectively tosses out the values the computer decides are not valid. Different not superior. Yields similar accuracy results over the same EXACT MER ranges. The US system defaults at 4000 meters. it does not mean you can't shoot. it means the computer will not decide the imput for you. That is the difference between the US and British gunnery algorithms loaded into the same EXACT FCS.

So in a sense BW is both right and WRONG. US gunnery tables inputted are ballistically matched to armor penetration kill reach which as I wrote above is defaulted at an arbitrary MER per type round selected. If the gunner can get a solution at 5000 meters he can set he can take the shot. He has to manually set the parameters though based on manual readouts. These are not automatic as in the German and British FCS software. The physics BS tries to claim degrades the laser is pure BS. The scatter of the beam is not that broad at 5000 meters. Its signal return threshhold  not beam scatter that results in the conflicting  range reads that the receiver picks up.

My source is GDLS. and CDC Canada

Herald

Herald

Western lasers are supposedly eye-safe so there are frequency bounds and  energy limits. Does that cause some atmospheric beam scatter? Yes, but it is the actual signal strength returns, the detector receives, that gives you those multiple range returns. Also consider refraction index, B. At what angle does the beam bounce off the object lased? That is your actual major scatter effect when you look at the optics behind lasing. The beam, itself, is relatively narrow.

Herald