George Elder wrote:Hi Jose:
I seem to recall vague (my emphasis -- Randy) claims being made in another thread regarding the supposed ability to reduce a photo-based speed estimate to a 0.5 knot error margin when all available experts noted that 2-3 knots would be more in the proper and "viable" range.
...the comment was quite specific
that a 0.5 knot error margin could be deduced and such appears now -- by the evidence we have to hand -- to be a very reasonable evaluation.
I know of no 'expert' who has staked out the position that Bismarck's speed at the Battle of the Denmark Strait could be estimated to within only 2 or 3 knots. Perhaps they'd be willing to come forward and justify the positions you have asserted for them.
George Elder wrote: ...With respect to yaw, it is well known that at 4-5 degrees yaw has a measurable influence on the flight dynamics of many penetrators, and this grows as the yaw increases -- depending on the nature of the penetrator. These data have been shared with the whole community via TechSpec. With regard to terminal ballistics, the influence of yaw has been amply demontrated by Goldsmith and others. These are rather specific studies -- and none of the 70+ interested parties who received the studies seemed to dispute them when they were offered (sic).
This all, of course, overlooks the valid points which Bill has made in his presentation on the topic -- again, the valid subject of a separate thread.
However, at this time, you have not made any points which contradict the information Bill has shared.
As Bill pointed out, Goldsmith has nothing to say about external ballistics and Bill challenged you to provide some indication as to how Goldsmith's views are relevant to the discussion at hand. Yet here again you merely assert Goldsmith's work without citing anything which we can evaluate vis-a-vis Bill's position.
As to the assertion that none of the 70+ parties disputed the studies fails to address whether these folks actually read and digested the material or whether they had concerns which they have not not bothered to voice.
Additionally, one may note that even if all 70+ people agreed with the findings this would fail a basic test of logic. After all, how many people believed Iraq had WMD ? The fallacy of common belief looms large in this assertion.
Nevertheless, insofar as you raised the topic, I feel the ball is in your court to articulate a valid observation and justify it with some manner of discussion which addresses Bill's position. Then we can form a better opinion as to whether your assertions are robust enough to rebut the comments Bill has generously posted.
I'm all for establishing a new thread on yaw and it would be interesting to see what results you may be able to manage with the formulae which have been noted here. I find it fascinating work and I would very much like to review any data you may present.
As Bill has pointed out, it is important to keep the focus on external ballistics rather than drifting -- if you'll pardon the pun -- off into terminal ballistics, which was not the basis for your initial comments regarding yaw as it relates to drag. It does strike me as a matter of education and rather than argumentation.