PHOTOGRAMMETRIC ENGINEERING & REMOTE SENSING
May 2020
271
by
Clifford J. Mugnier, CP, CMS, FASPRS
I
nhabited by late Stone Age people, many
megalithic tombs date from 2500 BC. Portugal
is one of the oldest nation states in Europe, and
its foundation in 1139 pre-dates Spain by nearly 350
years. The Ro-mans arrived in 216 BC, and named
the entire peninsula Hispania. However, the region
between the Douro and Tagus Rivers was named
Lusitania by the Celt-Iberian inhabitants. Later
overrun by Ger-manic tribes and then by the Moors,
eventually the kingdom of Portucale, comprising
León and Castile, was declared independent by King
Afonso Henriques. Portugal is slightly smaller than
Indiana; it is mountainous north of the Tagus River,
and has rolling plains in the south. With its only
border being Spain to the east and north, the North
Atlantic Ocean is on Portugal’s west and south.
Portugal holds sovereignty over the Azores and
Madeira Islands; both archipelagos are strategic
locations along the western sea with approaches to
the Strait of Gibraltar. The highest point is Ponta do
Pico on Ilha do Pico in the Azores at 2,351m.
According to the Portuguese Instituto Geográfico do
Exército (Army Map Service), in 1420, aware of the
navigational importance of cartography, Prince Henry the
Navigator commissioned the master cartographer Jácome of
Majorca to teach apprentice cartographers in Portugal the art
of preparing navigational charts. One of the oldest existing
maps, thought to have been pre-pared by the cartographer
Pedro Reinel, dates from 1500. Portuguese cartographers
of the period were considered the most skilled in the world,
their maps pro-viding the most accurate representation of the
Earth. Conscious of the importance of cartography in tackling
the country’s economic problems, Queen Mary of Portugal
created the Royal Military Archive in 1802, in order to house
the different national cartography departments. This body
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 Portuguese Republic was
originally printed in 2002 but contains updates to their coordinate
system since then.
was the precursor of the Military Geographic Institute. At
the end of the eighteenth century, having closely followed
the progress of this science, it was the Portuguese military
cartographers that established and developed the geodesic
(
sic
) network in Portugal. Modern Portuguese cartography
dates back to 1778 when work began on the first fundamental
geodetic triangulation network, which lasted until 1848. The
survey work for the 37 sheets which make up the Carta Geral
do Reino (General Map of the Kingdom), also known as The
Chorographic Map of Portugal, at a scale of 1:100,000, lasted
from 1853 to 1892. Produced al-most entirely by Army officers,
the map series was awarded the “Lettre de Distinction” during
the Paris International Congress of Geographic Sciences in
1875. Based on the Castello de Sâo Jorge Da-tum in Lisbon,
the ellipsoid of reference was the Bessel 1841 where
a
= 6,377,397.155 meters and the reciprocal of flattening (
1
/
f
)
= 299.1528128. The
projection de jour
in Europe at that time
was the ellipsoidal Bonne, and for this series the Latitude of
THE
PORTUGUESE
REPUBLIC
Photogrammetric Engineering & Remote Sensing
Vol. 86, No. 5, May 2020, pp. 271–273.
0099-1112/20/271–273
© 2020 American Society for Photogrammetry
and Remote Sensing
doi: 10.14358/PERS.86.5.271
