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Re: Air vs. Free Pistol

Posted: Mon Mar 30, 2015 8:02 pm
by john bickar
David Levene wrote:You'd be surprised (or maybe not) how few people can stand still without swaying, even with their arms by their sides.
QFT.

I would say less than 1 in 100, IME.

Re: Air vs. Free Pistol

Posted: Mon Mar 30, 2015 10:54 pm
by shaky hands
David Levene wrote: SCATT doesn't track the position of the muzzle or its velocity. It tracks where the gun is pointing, (from memory) 125 times per second.

It doesn't know why a gun is not pointing at the centre of the target, it just knows that it isn't (buy a calculated amount).

It can't tell whether that's because the front and rear sights are out of alignment (angular error) or because the upper torso, eyes, arm, wrist, rear sight and front sight are all still perfectly in alignment with each other but have all moved away from the centre of the target by the same amount (parallel error).

SCATT can tell exactly where the gun is pointing on the target, but that is only for the actual distance to the target. If you are trying to simulate shooting at a different distance then it is less accurate. It assumes that any gun not pointing at the centre of the target is because of an angular error and multiplies the size of the error accordingly.
Interesting. I would like to learn more about the actual algorithms built into SCATT. How did you learn all that, David? Is it something SCATT openly discloses?

On the basis of what you explained, it seems that simulated 50m shooting at 10m (or less) should be more difficult than the actual shooting -- if the entire error is attributed by SCATT to the angular error, that error is overestimated. This is because the parallel error, which should not be multiplied by a factor of 5, is in fact multiplied by the program nevertheless. I am may be fooling myself, but I have often felt that the actual free pistol shooting was just a little bit easier than the simulated SCATT practice.

Re: Air vs. Free Pistol

Posted: Tue Mar 31, 2015 1:01 am
by David Levene
shaky hands wrote:Interesting. I would like to learn more about the actual algorithms built into SCATT. How did you learn all that, David? Is it something SCATT openly discloses?
Back in the mid-late 90s I did a lot of work with Scatt and the GBR Standard, Centre-Fire and Sport pistol squads. I got fairly friendly with their then Export Manager (a Brit) and picked his brain.

At the root of the Scatt system is a table of x-y coordinates, as I said (from memory), 125 sets per second, of where the sensor/gun is pointing on the target frame. Everything else is just basic geometry, statistics and user interface. it's actually very simple, but extremely effective.

shaky hands wrote: On the basis of what you explained, it seems that simulated 50m shooting at 10m (or less) should be more difficult than the actual shooting -- if the entire error is attributed by SCATT to the angular error, that error is overestimated.
No argument from me on that one, but remember that for pistol shooting the vast majority of errors will be angular.

I have no proof but suspect that the majority of intrinsic errors in Air Rifle will be parallel. This could be a reason why AR shooters seem to place such importance on their shooting boots. (lights blue touch paper and retires)

Re: Air vs. Free Pistol

Posted: Tue Mar 31, 2015 9:37 am
by shaky hands
David Levene wrote:I have no proof but suspect that the majority of intrinsic errors in Air Rifle will be parallel. This could be a reason why AR shooters seem to place such importance on their shooting boots. (lights blue touch paper and retires)
This in fact could be testable, if we assume SCATT's inability to tell angular errors from parallel ones. When simulated 50m rifle shooting at 10m one should then obtain significantly greater shot displacement, much more so than in free pistol. Is it something that rifle shooters report?