Coordinates
Subject: Coordinates
From: Aubrey O'Callaghan (ocallaghan@XXX.XXX)
Date: Tue Sep 25 2001 - 22:08:39 EDT
As an engineer I have come across an interesting set of coordinates.
In Venezuela these is a coordinate system called La Canoa. Apparently it is
referenced to a cathederal in the city of Maracaibo.
La Canoa is based on an inverse flattening of 1/297 (WGS84 is 1/298.257223)
with semi major axes of 6378388 and 6378137 respectively.
I have in front of me 2 sets of coordinates one based in "La Canoa
coordinates", the other in WGS84. I am surprised to find a difference in
the longitude. Does anybody have an explanation for the longitude change ?
WGS84: 10 deg 14 min 00.77sec N 71 deg 28 min 23.70 sec W
La Canoa: 10 deg 14 min 12.28 sec N 71 deg 28 min 16.52 sec W
It should be noted that the information I have for the La Canoa gives the
spheroid as International
and datum as La Canoa, I think that this is the Hayford International
spheroid.
The WGS 84 gives the spheroid as WGS84 and the datum as WGS 84.
As I said earlier the longitude change has me intrigued, but I can find no
reason for the change in Admiralty Navigation books (I have not a copy of
Bowditch).
Aubrey.
