Subject: RE: [BoundaryPoint] Re: EGLYSD class b
Date: Jan 05, 2006 @ 19:47
Author: Hugh Wallis ("Hugh Wallis" <hugh@...>)
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Aha - here is the description of how confluence.org deal with confluences on borders (http://www.confluence.org/infoconf.php#owner). It appears that this doesn't add anything of use to our disucssion
 

Confluences on borders
Confluences exactly on the Northern and Eastern borders of a state, province or country will be included in that state, province or country. Confluences on the Southern and Western borders will be included in the bordering state, province or country.

Historically, borders were defined by a variety of methods, and most that refer to specific coordinates were done long before the WGS84 system was defined. As a result, sometimes the above rule isn't needed for "border confluences". For example, the Canada/United States border, from 123°W on the the west coast to 96°W between Manitoba and Minnesota, when viewed using WGS84 coordinates, is actually a line that zig-zags back and forth across the 49th parallel. None of the confluences along the border are actually on the border, so they belong to the province/state in which they are located. If this part of the Canada/United States border was defined as the WGS84 49th parallel, then the above rule would apply, and all these confluences would belong to the United States. See the Canada page for more information.


From: BoundaryPoint@yahoogroups.com [mailto:BoundaryPoint@yahoogroups.com] On Behalf Of Hugh Wallis
Sent: Thursday, January 05, 2006 2:16 PM
To: BoundaryPoint@yahoogroups.com
Subject: RE: [BoundaryPoint] Re: EGLYSD class b

Oh good - those pictures reappeared - they weren't there the other day so I wrote to the confluence.org coordinator for that region and that seems to have fixed it. It is a shame that they didn't take a GPS reading at the border post (which is what they call it) to indicate whether it was located on the 22°N parallel according to WGS84 or was some minutes/metres distant from that line.
 
One thing I haven't yet detemined is how confluence.org decided which country to record confluences as being in when they are nominally on a border. In every case they have made such a decision rather than listing a confluence as being in more than one country or state (or equivalent), probably because their website organisation and database structure forced them to, but I would like to know for sure what their logic was. Following links from their site I did reach the following page - http://www.colorado.edu/geography/gcraft/notes/datum/edlist.html - which is instructive since it lists the deviation from WGS84 (which is the datum used by confluence.org) for most regions of the world.
 
We can see from this that datums commonly used in Egypt and Sudan differ in their deviations from WGS84 by various amounts but typically in the order of 130 to 200 metres (sqrt(dx^2 + dy^2)) and Libya is not mentioned. So, unless the borders and tripoint are statutorially or by treaty defined as being on the 25°E meridian and 22°N parallel using WGS84 it is evident that the intrepid explorers who made it to 22°N, 25°E (WGS84) were in all probability a good distance from the actual tripoint. It is also conceivable that we have a tripoint here that is not fully defined (as envisaged in the Indonesian paper) because of different datums possibly having been used (or not specified at all) in different treaties and the location not have been surveyed and agreed to in a tripartite agreement. It is conceivable that until and unless it is ever determined by one of the parties that it actually matters and the issue is renegotiated the situation might remain as indeterminate as those described in the Indonesian paper. All speculation of course but in the absence of any definitive evidence in favour of WGS84 being the datum used by the three countries to determine the position of their borders I would vote (inasmuch as my vote actually means anything!) against calling this a class B find given that there seems to be plenty of evidence of "reasonable doubt". Obviously I would also be prepared to change my vote if such definitive evidence in favour of WGS84 surfaced.

From: BoundaryPoint@yahoogroups.com [mailto:BoundaryPoint@yahoogroups.com] On Behalf Of Jesper Nielsen
Sent: Thursday, January 05, 2006 1:19 PM
To: BoundaryPoint@yahoogroups.com
Subject: SV: [BoundaryPoint] Re: EGLYSD class b

Could this be EGSD demarcation?

http://www.confluence.org/photo.php?visitid=11575&pic=ALL

 

Who reads Arabic? Isn’t the left symbol five-something?

 

Jesper

 

Fra: BoundaryPoint@yahoogroups.com [mailto:BoundaryPoint@yahoogroups.com] På vegne af aletheiak
Sendt: 5. januar 2006 07:56
Til: BoundaryPoint@yahoogroups.com
Emne: [BoundaryPoint] Re: EGLYSD class b

 

& a very sweet dream indeed as well as a brilliant analysis & synthesis dear doctor
but off the top of my head
egsd even in the wadi halfa nile salient was last reported totally undemarcated as of 1962
per ibs
so your valiantly won trilaterality & tridatum intersection appears to evaporate in the
desert

but hardy & steady as she blows matey for we are whaling in mirage country here

& something seems to be turning up

yes
per the other ibs
egly has its mediterranean border base at a place called beacon point
no relation
& was reportedly marked by beacons 206 miles inland from there

& this strange note with perhaps a new clue

on 15dec1937 a commission met & arranged to move some of the boundary pillars
westward in order to improve intervisibility & to delimit the boundary as a series of
straight lines between beacons instead of the previous line which followed the tracks
between the beacons
& 9 extra beacons were erected at this time bringing the total to 187
& this whole chain of permanent beacons was reported satisfactorily completed in a proces
verbale dated 3may1938
which
could well tell us or lead us to the egly datum
if we ever did find an egsd datum
for completing the still elusive intersection & triangulation you propose

also & stranger
a whole fresh chain of border arcs mike kaufman & i missed in our crazy arc census is
built into egly tho not quite nakedly visible in here
http://www.law.fsu.edu/library/collection/LimitsinSeas/maps/bs61.html
but thats just for titillation & profits us nothing


&
aha
but here in the lysd ibs your point & synthesis are finally made in earnest
still hypothetically of course but its a warm lead
for it indicates
23 or 24 miles south of eglysd
lysd appears to be demarcated by 12 boundary beacons

however no info available on their type or condition

funny way to put it & unusual circumstance too
but it points toward a lost treaty text & in it perhaps a lost lysd datum
which
when combined with our more hopefully found egly datum
completes your proposed trilateral datum cross artifice by the back door

of course we still have to track down the one ordinary egly & this other mystery lysd treaty
but its a way to proceed
superchallenging as it may seem

but something better to pursue in daylight i would think

so keep on dreamin

--- In BoundaryPoint@yahoogroups.com, "Lowell G. McManus" <lgm@w...> wrote:
>
> While the EGLYSD tripoint has almost certainly never been surveyed according to
> any datum whatsoever, it seems likely that other segments of the EGLY meridional
> boundary (farther north) and of EGSD (in the vicinity of the Nile Valley) have
> been surveyed and demarcated.  Shouldn't the same datum that was used in those
> surveys be applied along the whole length of the respective meridian and
> parallel, since it has already been accepted by the parties?
>
> I am reminded that it was the ancient Egyptians who invented surveying to
> reestablish cadastral boundaries when the annual Nile floods erased landmarks.
>
> Lowell G. McManus
> Leesville, Louisiana, USA
>
>
> ----- Original Message -----
> From: "aletheia kallos" <aletheiak@y...>
> To: <BoundaryPoint@yahoogroups.com>
> Sent: Wednesday, January 04, 2006 10:51 PM
> Subject: RE: [BoundaryPoint] Re: EGLYSD class b
>
>
> > nice stuff thanx
> > & please look for quite a few inserts ahead
> >
> > --- Hugh Wallis <hugh@o...> wrote:
> >
> >> >>thus as likely wgs84 as any<<
> >>
> >> definitely won't be WGS84 since that was not in use
> >> until 1984 (hence the
> >> "84" in its name).
> >
> > hahaha you certainly may disallow me & i knew dat
> > about 84
> > but i dont infer wgs84 should be ruled out for that
> > reason
> >
> > on the contrary i think the relative newness &
> > universality of wgs84 may especially recommend &
> > automatically promote it in this special case
> >
> > for diametrically unlike the maritime borders of
> > indonesia
> > where technical & legal complications create a
> > particular urgency to get all these datums clarified
> > the situation at eglysd smacks of complete
> > indifference & utter neglect over many decades
> >
> > & so i reason in the apparent absence of any evidence
> > of a specified datum for this point since its creation
> > in 1925 til the present
> > that it either remains unspecified until today & thus
> > highly subject to the wgs84 default principle
> > or else that any specificity it may have acquired
> > would most likely have occurred post 1984 & would thus
> > very likely be in the form of wgs84 for that reason as
> > well
> >
> > also where so many as 3 parties are involved universal
> > norms tend to be preferred to local ones
> >
> > your indonesia text says flat out
> > for its own special case but with universal
> > applicability in this case
> > wgs84 seems to be most sensible to adopt
> > &
> > all decisions should be legally agreed by all
> > countries involved
> >
> >> I suspect that the Egypt 1907 Datum might have been
> >> used
> >
> > but what in particular leads you to guess egypt 1907
> >
> > i can imagine egypt & sudan adopting it but not so
> > readily libya
> >
> >> - but see
> >>
> > <http://www.fig.net/pub/cairo/papers/ts_45/ts45_01_abidin_etal.pdf>
> >>
> > http://www.fig.net/pub/cairo/papers/ts_45/ts45_01_abidin_etal.pdf
> >>  where it
> >> notes, using Indonesian maritime boundaries as its
> >> focus, that often the
> >> datum is NOT specifically denoted in a relevant
> >> treaty
> >
> > exactly my point as well as my guess here at eglysd
> > since day 1 in 1925 & even up to the present
> >
> >> and discusses the
> >> issues that arise as a result.
> >
> > yes naturally many in the worlds busiest seas but none
> > in the worlds most desolate wasteland
> >
> >> If you don't have
> >> time to read the whole
> >> paper
> >
> > who me
> > i have all the time in the world for such
> > deliciousness
> >
> >> the following section from the summary can
> >> help to understand the
> >> thesis:
> >>
> >> "The uncertainty in geodetic datum of boundary
> >> points introduces
> >> complications and problems
> >> in spatial management of Indonesia's maritime
> >> boundaries, since it can
> >> displace the boundary
> >> lines from their assumed true location. The
> >> displacements of boundaries in
> >> WGS84 datum are
> >> generally in the order of a few hundred meters, i.e.
> >> about 200 to 400 m ,
> >
> > indeed did you notice 420m was the max they cited
> > later in the article
> >
> > sounds like your datum shift demo wants to take place
> > in the indonesian jungles
> >
> >> depending on the
> >> assumed original geodetic datum of the boundaries
> >> stated in the treaties.
> >> These boundary
> >> displacements are spatially advantageous for
> >> Indonesia in some cases and
> >> also
> >> disadvantageous in others."
> >
> > i also appreciated & hope you did too the specific
> > reference in this article to the attainment of
> > submeter level accuracy in pilotage by ecdis dgps in
> > 2004
> > which nicely fills in a blank space in our earlier
> > discussion here
> > http://groups.yahoo.com/group/BoundaryPoint/message/18568
> >
> > end inserts
> > & sweet dreams
> >
> >
> >> The following paper might be relevant to EGLYSD -
> >>
> > http://www.asprs.org/resources/grids/06-2003-kenya.pdf
> >> - although it
> >> primarily refers to Kenya it also mentions the use
> >> of various datums in
> >> Egypt and the Sudan.
> >>
> >> Googling "latitude longitude datum egypt" will
> >> provide a host of other links
> >> too numerous to reproduce here that will provide a
> >> wealth of additional
> >> information.
> >>
> >>
> >>
> >>
> >>   _____
> >>
> >> From: BoundaryPoint@yahoogroups.com
> >> [mailto:BoundaryPoint@yahoogroups.com]
> >> On Behalf Of aletheiak
> >> Sent: Wednesday, January 04, 2006 8:33 PM
> >> To: BoundaryPoint@yahoogroups.com
> >> Subject: [BoundaryPoint] Re: EGLYSD class b
> >>
> >>
> >> there is no mention in any of the relevant ibs
> >> numbers that the 1925 italian
> >> egyptian
> >> agreement establishing this tripoint or the 1934
> >> italo british egyptian
> >> agreement
> >> reaffirming it included any official maps or even
> >> specified any official
> >> datum or datums
> >>
> >> various british french american & north african maps
> >> of the 1930s thru 1960s
> >> tho are said
> >> there to reliably depict the various borders
> >> convergent here at eglysd
> >>
> >> & one cant conclude the datum is elusive for it
> >> might well just be the
> >> common &
> >> nonelusive default datum of
> >> none specified
> >> & thus as likely wgs84 as any
> >> in which case the try or rather the result would
> >> indeed be a very loose
> >> class b
> >> as represented by the little man in the gully in the
> >> first pic
> >> or more likely a tight class c at probably 14 meter
> >> range
> >> but if this is not correct
> >> then there remains some possibility of a class d or
> >> even class e
> >>
> >> for there also remains an outside chance that the
> >> tripoint is in fact marked
> >> whether by an official durable marker
> >> since some other parts of these remote borders are
> >> so marked
> >> or even by just some little cairn or something these
> >> folks could have missed
> >> since there is also no evidence that they were
> >> really studying the border
> >> alignments or
> >> trying for the tripoint in any other way than just
> >> for the lat long
> >> intersection
> >>
> >> --- In BoundaryPoint@yahoogroups.com, "aletheiak"
> >> <aletheiak@y...> wrote:
> >> >
> >> > wow
> >> > nicely done
> >> > & a pleasure to see the shots back on goal & the
> >> discussion back on target
> >> again
> >> >
> >> > & since all 3 ibs numbers
> >> > 10 & 18 & 61
> >> > join brownlie in indicating this tripoint is
> >> unmarked
> >> > or at least was unmarked as recently as 1979
> >> > it is hard to argue with the bona fides of their
> >> perfect gps readings
> >> > no matter what datum they may have been using
> >> >
> >> > but since even they are only claiming 14 meter
> >> range at best
> >> > & were having difficulty getting it
> >> > i think i would credit them only with a class c
> >> > as in seeing the objective for certain with their
> >> eyes
> >> > somehow
> >> > at some point
> >> > in their overall visitation process
> >> > rather than a class b
> >> > as in necessarily having been at the exact spot
> >> with their bodies
> >> > for i think that honor would remain to be won
> >> > in this unusual circumstance
> >> > by someone with a better quality gps receiver
> >> >
> >> > --- In BoundaryPoint@yahoogroups.com, "Jesper
> >> Nielsen" <jesniel@i...>
> >> wrote:
> >> > >
> >> > > Thanks to the unknown visitor to Borderbase, who
> >> submitted the entry
> >> > >
> >> > >
> >> > >
> >> > > http://www.confluence.org/confluence.php?lat=22
> >> > > <http://www.confluence.org/confluence.php?lat=22
> >>
> > <http://www.confluence.org/confluence.php?lat=22&lon=25>
> >> &lon=25> &lon=25
> >> > >
> >> > >
> >> > >
> >> > > Jesper
> >> > >
> >> > >
> >> > >
> >> > > --
> >> > >
> >> > > Borderbase - your online guide to international
> >> borders and tripoints
> >> > >
> >> > > http://www.nicolette.dk/borderbase
> >> > >
> >> >
> >>
> >>
> >>
> >>
> >>
> >>
> >>   _____
> >>
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> > === message truncated ===
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