Subject: but why suppose an eglysd datum has ever been stated or even can be synthesized<br/>
Date: Jan 11, 2006 @ 03:25<br/>
Author: aletheia kallos (aletheia kallos &lt;aletheiak@...&gt;)<br/>
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<div id="ygrps-yiv-1264312108">yikes i have been so gulled into thinking we are<br/>
dealing with a set of normal boundaries here at eglysd<br/>
& that they will be behaving like any others<br/>
like <br/>
for example <br/>
by my just assuming <br/>
that the only convergent of the 3 that has been<br/>
somewhat normally demarcated would have therefore<br/>
necessarily been datumized <br/>
<br/>
<br/>
but obviously all 3 of these eglysd boundaries are<br/>
about as nonnormal & neglected as can be<br/>
not only in point of their general remoteness &<br/>
wildness<br/>
but also in point of their muslim indifference<br/>
<br/>
<br/>
for i have just realized that tho we can certainly<br/>
expect to find some documentation of the 1927 egit<br/>
demarcation commission somewhere & possibly even its<br/>
survey plats<br/>
the mapping of desolate wastelands even today is<br/>
rarely if ever done to a large enough scale for a<br/>
datum to become noticeable<br/>
<br/>
& for good reason<br/>
<br/>
for in such extreme deserts as we are talking about<br/>
here<br/>
even more than on any ordinary multipointing try <br/>
a shift in datum would tend to be of no practical<br/>
consequence & thus purely academic at best<br/>
<br/>
indeed only in the gps era could a datum ever have<br/>
mattered in such remote areas<br/>
& what it matters for even now seems to be only a<br/>
matter of entertainment & curiosity value  <br/>
rather than anything really practical that i can think<br/>
of<br/>
<br/>
& therefore<br/>
i hypothesize<br/>
even the semi european 1927 egit demarcation<br/>
commission<br/>
could very easily have deliberately dispensed with &<br/>
neglected to specify a datum on their plats or<br/>
anywhere in their report<br/>
& likewise the 1938 proces verbal on the 9 marker<br/>
modifications<br/>
<br/>
for monument coords in undatumized integral degminsec <br/>
or roughly 100 foot squares <br/>
would have served everyone just fine in all 3 of these<br/>
delimitation areas<br/>
including all along egly <br/>
which is the least remote of them<br/>
& even if these coords wandered or erred by another<br/>
second or even several for any reason<br/>
well who would ever have cared or noticed anyway <br/>
so long as the monuments hove into view when being<br/>
looked for<br/>
<br/>
& intervisibility of monumentation was reportedly very<br/>
important if not the whole deal on egly <br/>
as far inland as the demarcation went anyway<br/>
<br/>
<br/>
i am also reminded that as recently as 20 years ago<br/>
usgs topos in scales equal to the largest known<br/>
nonurban egyptian & libyan ones<br/>
namely 1 to 100k <br/>
allowed 50 meters of fudge<br/>
<br/>
& the state of 1927 survey & mapping art at least<br/>
doubled that standard potential deviation<br/>
<br/>
so there is really little reason to suppose anyone<br/>
cared about the datum then <br/>
or even has cared ever since <br/>
<br/>
or dont you agree <br/>
now that we have looked at it again<br/>
<br/>
<br/>
it may well be that all 3 countries have gone to<br/>
completely modern gis systems in the meantime<br/>
but that is still no reason to conclude that their<br/>
borders have ever been expressed in so exacting a way<br/>
bilaterally or trilaterally<br/>
<br/>
<br/>
so now that i have had all this time to research &<br/>
think about it<br/>
more to the point than datum chasing <br/>
it seems to me<br/>
as well as the best we can probably really hope to do<br/>
in any case now <br/>
would be to simply find the true longitude of the<br/>
nearest 25th meridian egly rock in any datum<br/>
using a pilotage gpsr of course for submeter accuracy<br/>
& extend that meridian to its intersection with the<br/>
22nd parallel in the same datum<br/>
to nail the correct or at least the most likely & best<br/>
available square meter <br/>
in any datum anyone likes<br/>
<br/>
<br/>
& then btw compare this with wgs84 if it isnt already<br/>
expressed that way<br/>
so as to correctly classify the 22x25 confluence photo<br/>
try that set off & indeed has kept inspiring this<br/>
entire tryfull caravanserai of delights<br/>
as well as place the extrapolated tripoint position<br/>
within its frame & in relation to the subject in the<br/>
photo<br/>
<br/>
like how close really was that dude anyway<br/>
<br/>
<br/>
& this closest & most necessary reference rock<br/>
most likely number 178 of the original 1927<br/>
demarcation<br/>
is indicated by the ibs to be on the 25th meridian<br/>
around 487 miles due north of eglysd<br/>
or in other words at around the 29th parallel<br/>
<br/>
<br/>
& of course the down side of this method is that we<br/>
will probably have to actually go there to africa to<br/>
do it ourselves<br/>
rather than being able to expect to have the answer<br/>
delivered to us from an archive<br/>
<br/>
but at least i think we have probably dispelled one<br/>
more probable mirage<br/>
which is that you cant get there from the archive in<br/>
this case<br/>
<br/>
<br/>
 <br/>
<br/>
   <br/>
 <br/>
<br/>
<br/>
<br/>
<br/>
<br/>
<br/>
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