PHOTOGRAMMETRIC ENGINEERING & REMOTE SENSING
February 2019
87
by
Clifford J. Mugnier, CP, CMS, FASPRS
O
riginally settled in the Bronze Age, the
Umm an-Nar’s culture established itself
near modern Abu Dhabi in the 3rd century
B.C., and its influence extended to the interior of
the Arabian Peninsula as well as along the coast
to Oman. Some later settlements by the Greeks
have been found, and in the Middle Ages most of
the region was part of the Kingdom of Hormuz,
which controlled trade in the Arabian Gulf. The
Portuguese arrived in 1498 and stayed until
1633 until the British took control of the area. By
1820, the British had destroyed or captured all
Qawasim pirate ships, imposed a General Treaty
of Peace on nine Arab sheikhdoms in the area, and
installed a garrison. The area was known as the
Trucial Coast until 1971
.
The seven emirates are Abu Dhabi (Abu Zaby), ‘Ajman,
Dubai (Dubayy), Al Fujayrah, Ra’s al Khaymah, Sharjah (Ash
Shariqah), and Umm al Qaywayn. The United Arab Emirates
(UAE) cover an area slightly smaller than the state of Maine.
Much of the interior of the UAE is desert and runs to the
edge of the Empty Quarter of Saudi Arabia, the largest sand
desert in the world. The northern and eastern sections are
mountainous and green while the coastal areas are marked
with salt flats.
The first major geodetic datum of the Arabian Gulf area
was established by W.E. Browne of the Iraq Petroleum Com-
pany in 1927-1931 at the South End Base at station Nahr-
wan (East of Baghdad) such that:
F
o
= 33° 19´ 10.87˝ North,
L
o
= +44° 43´ 25.54˝ East of Greenwich, and the Clarke 1880
is the ellipsoid of reference where: a = 6,378,300.782 m, and
1
/
f
= 293.4663077. The Nahrwan Datum of 1929 is the most
prevalent coordinate system of the entire Arabian Gulf area
and is still found to this day.
The Sir Bani Yas Island Datum of 1933 was established by
the British Royal Navy in 1933 such that:
F
o
= 24° 16´ 44.83˝
The Grids & Datums column has completed an exploration of
every country on the Earth. For those who did not get to enjoy this
world tour the first time,
PE&RS
is reprinting prior articles from
the column. This month’s article on the United Arab Emirates was
originally printed in 2001 but contains updates to their coordinate
system since then.
North,
L
o
= 52° 37´ 17.63˝ East of Greenwich, and the Clarke
1880 is the ellipsoid of reference.
The Ajman Datum of 1946 origin is such that:
F
o
= 25° 23’
50.19˝ North,
L
o
= 55° 26’ 43.95˝ East of Greenwich and is
referenced to the Helmert 1906 ellipsoid where a = 6,378,200
m, and
1
/
f
= 298.3. The first Grid was the WWII Trucial Coast/
Qatar Grid on the Cassini-Soldner projection. The Central
Meridian
l
o
= +50° 45’ 41˝ E, the False Northing Latitude of
Origin (
j
FN
) = 25° 22’ 56.5˝ N, and both the False Eastings
and False Northings are 100 km. Of course, the scale factor at
origin by definition is equal to unity.
In 1967, the Directorate of Military Surveys recomputed
the Mainland Trucial Coast and Qatar triangulations on the
International Ellipsoid, European Datum 1950. Those coordi-
nates were then transformed into Nahrwan Datum 1929. The
Trucial Coast Transverse Mercator Grids became preferred
to the old Cassini Grid. The Central Meridian
l
o
= +55° 00’ E,
and the False Eastings have had values of 100 km and 1,200
km. The False Northings are –2,000 km as measured from
the Equator. The series covered the entire UAE. Topograph-
Photogrammetric Engineering & Remote Sensing
Vol. 85, No. 2, February 2019, pp. 87–88.
0099-1112/18/87–88
© 2019 American Society for Photogrammetry
and Remote Sensing
doi: 10.14358/PERS.85.2.87
