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If ML was using survey data based on the Egyptian map grid then this may explain the discrepance. Strictly speaking you should always quote what system you are using when you quote coordinates.


Given the number of decimal places he is quoting to, it sounds like this is Total Station data - so may be tied into the local grid system rather than the GPS system.

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The single Survey of Egypt monument of record in the area was a brass disk atop the Khufu pyramid. During the second season we coordinated that point by triangulation from GP1 and GP8.

The recorded latitude and longitude of this point are:
N 29° 58’ 44.3830”
E 31° 07’ 57.0194”
(Helmert Spheroid of Reference.)