PHOTOGRAMMETRIC ENGINEERING & REMOTE SENSING
September 2017
605
by
Clifford J. Mugnier, CP, CMS, FASPRS
T
he Río de la Plata (Silver River) was dis-
covered by Solís in 1516, and Argentina
was first explored by Sebastian Cabot from
1526-30. Pedro de Mendoza founded the first per-
manent colony at Buenos Aires (good winds) in
1536. Argentina received its independence from
Spain in 1816, and it is the second largest country
in South America after Brazil. The northern Cha-
co and thecentral Pampas are vast expanses of flat
land, which is the home of the Argentine cowboy,
the Gaucho. Elevations in Argentina range from –
40 m to +6962 m (+22,841 ft.) on Aconcagua, the
highest peak in the Western Hemisphere.
In 1826, the Topographic Department of the Province of
Buenos Aires was founded. A national agency responsible
for mapping the entire country was created on the 5th of
December, 1879 as the Oficina Topográfica Militar (Military
Topo- graphic Office). By 1901, the Army General Order No.
37 changed the name to the Instituto Geográfico Militar
(Military Geographic Institute) which is a name that
continues to this day. By 1943, the Argen- tine version of “La
Ley,” (The Law) was legislated giving the Army’s Instituto
Geográfico Militar (IGM) the national monopoly on large-
scale topographic mapping. (See my column on Ecuador that
had a short sociological commentary on the common Latin
Americanmapping monopolies – Honduras was an exception).
Argentina’s organization or its mapping agency followed
the European practice of the time. The early Argentine
“Anuarios” (yearbooks) of the 1900’s actually de- tailed the
various military topo- graphic organizations of Europe.
In 1887 the old astronomical observatory at Córdoba
established the longitude of its meridian circle as: Λ
o
=
-68° 12´ 03.3˝ West of Greenwich. The first geodetic-quality
astronomical (“Astro”) station observed was in 1894 at the
geodetic pillar in the Army Barracks in Mendoza where: Φ
o
=
–32° 52´ 54.8˝ South, Λ
o
= –68°51´ 22.8˝ West of Greenwich. At
THE REPUBLIC OF
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 Republic of Argentina was
originally printed in 1999 but contains updates to their coordinate
system since then.
the time, the Argentines were using the Bessel 1841 ellipsoid
where the semi- major axis (a) = 6,377,397.155 meters and
the reciprocal of flattening (
1
/
f
) = 299.1528128. Initial plans
for establishing geodetic control in the country were for a
perimeter survey of the Atlantic coastline, as well as along the
international and provincial borders. This plan was modified
in 1912 to consist of 2° x 2° quadrilaterals formed by chains
of triangulation. The classical geodetic triangulation network
of Argentina reflects strict adherence to this plan as it exists
today. Practically every- where else in the world the chains
have been dictated by the topogra-phy. That is, triangulation
stations commonly are located on the summits of hills and
mountains. Since so much of the Argentine country consists
of the very flat Chaco and Pampas, the topography had no
Photogrammetric Engineering & Remote Sensing
Vol. 83, No. 9, September 2017, pp. 605–608.
0099-1112/17/605–608
© 2017 American Society for Photogrammetry
and Remote Sensing
doi: 10.14358/PERS.83.9.605
