PHOTOGRAMMETRIC ENGINEERING & REMOTE SENSING
July 2019
475
by
Clifford J. Mugnier, CP, CMS, FASPRS
T
he area of Northern Africa currently known
as Algeria was brought under Roman rule
during the Second Punic War (218 – 201
B.C.). It was known to the Romans as Numidia. It
was conquered by the Arabs in the 8th century and
was mainly under the rule of the Ottoman Empire
until 1705, then it was occupied by the French in
1830. Algeria gained independence from France
following a referendum of 01 July, 1962. Algeria
is the second largest country in Africa after the
Sudan, with its coastline on the Mediterranean
Sea extending for 998 km. Algeria is bounded by
Tunisia and Libya on the east, by Niger and Mali
on the south, and on the west by Mauritania, the
former Western Sahara, and Morocco. The highest
point is Tahat at 3,003 m, and the lowest point
is Chott Melrhir at –40 m. Algeria is mostly high
plateau and desert; the Atlas and Saharan Atlas
Mountains are in the north along with narrow
discontinuous coastal plains.
The triangulation of Algeria was carried out by the Dépôt
Général de la Guerre from 1854 to 1887. After 1887, the So-
ciété Géographique de l’Armée, headquartered in Paris, con-
tinued the work. The first-order net of triangulation consists
essentially of two parallel chains and three meridional chains.
The parallel chains are the coastal chain from the Moroccan
to the Tunisian borders (1860-1868) and the chain Aïn Se-
fra-Laghouat-Biskra-Gabes (in Tunisia) (1889-1895). There
are also two shorter parallel chains: the Guerara tie chain
(1909-1910) and the Southern El Oued tie chain (1909-1910).
The meridional chains are the Biskra chain (1872-73, 1899-
1902), the Laghouat chain (1886, 1899-1902), and the Saïdia
chain (1896-97). Fill nets of first-order complementary, sec-
ond-order, and third-order triangulations were surveyed from
1864, following the pattern of planned mapping. The survey
DEMOCRATIC AND POPULAR
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 Democratic and Popular
Republic of Algeria was originally printed in 2001 but contains
updates to their coordinate system since then.
work was executed and adjusted in 94
cartonnés
(books of
sections), which progressed south-ward from the coastal ar-
eas according to military requirements. These
cartonnés
were
numbered in
chronological
sequence of completion. Note that,
in the English-language literature of North African Geodesy,
one will likely find “carton,” the derivative of
cartonné
.
This original work comprised the Colonne Voirol Datum of
1875, commonly termed Voirol 75. The fundamental point is at
the geodetic pillar of the Colonne Voirol Observatory, and the
astronomical coordinates are Φ
o
= 36° 45´ 07.9˝ N (40
G
8357.8˝)
and Λ
o
= 3° 02´ 49.45˝ East of Greenwich (0
G
7887.3˝ East of
Paris). The reference azimuth from south to Melab el Kora is
α
o
= 322° 16´ 52.7˝ and the ellipsoid of reference is the Clarke
1880 (IGN) where
a
= 6,378,249.2 m, and
1
/
f
= 293.4660208.
Mediterranean Sea
NORTH
ATLANTIC
OCEAN
Niger
Irhazer
Oua-n-Agadez
Édjérir
O
u
e
d
D
r
â
a
O
u
e
d
M
o
u
l
o
u
y
a
Straitof
Sicily
TyrrhenianSea
Chottel
Jerid
Chott
Melrhir
Chottel
Hodna
Chottech
Chergui
R
í
o
G
u
a
d
i
a
n
a
O
u
e
d
S
e
b
o
u
É
d
j
é
r
i
r
Sebkha
AzzelMatti
StraitofGibraltar
Tagus
V
a
l
l
é
e
d
e
l
'
A
z
a
o
u
a
k
28
36
28
36
20
0
8
0
8
8
BALEARIC
ISLANDS
(SPAIN)
Sardinia
(ITALY)
Sicily
(ITALY)
Isoladi
Pantelleria
(ITALY)
Ibiza
Majorca
S P A I N
PORTUGAL
MOROCCO
M A L I
N I G E R
LIBYA
MAURITANIA
TUNISIA
Western
Sahara
Palermo
Trapani
Càgliari
Bizerte
Kairouan
Sousse
Sfax
Gafsa
Gabès
Medenine
Tataouine
Az
Zawiyah
Zuwarah
Nalut
Tozeur
Touggourt
Tripoli
Tunis
HassiMessaoud
Algiers
Faro
Setúbal
Kidal
Tessalit
I-n-Guezzâm
Arlit
Ingal
Agadez
Valencia
Alicante
Albacete
Cartagena
Murcia
Almería
Granada
Córdoba
Málaga
Sevilla
Cadiz
Huelva
Lisbon
Béja
Jendouba
ElKef
Djanet
Ghat
Al ’Uwaynat
Illizi
Tamanrasset
Adrar
I-n-Salah
AïnSefra
ElBayadh
Arzew
Rabat
Meknès
Kenitra
Tangier
Tétouan
Fès
Casablanca
El Jadida
Marrakech
Ouarzazate
Safi
Tindouf
Tata
ErRachidia
Oujda
BouArfa
Taoudenni
Aguêraktem
(well)
AlHoceïma
Ghadamis
Béchar
Badajoz
I-n-Amenas
Ouargla
ElGolea
Médéa
Djelfa
Laghouat
Chlef
Batna
Biskra
Tébessa
Tlemcen
Saïda
Ghardaïa
Naama
Tiaret
Sétif
ElOued
’Aïn
Temouchent
SidiBel
Abbès
Mascara
Oran
Mostaganem
Boumerdas
Relizane
Annaba
Skikda
Jijel
Bejaïa
BordjBou
Arréridj
SoukAhras
Tizi
Ouzou
Blida Bouira
Constantine
Oum elBouaghi
BeniOunif
Figuig
BordjOmarDriss
Reggane
Bou
Saâda
Nabeul
Kasserine
Bourem
Taza
Timimoun
Base 802562AI (C00207) 8-01
Gibraltar
(U.K.)
Ceuta
(SP.)
Melilla
(SP.)
-
-
-
--
-
-
Abadla
Zagora
Oued
Zem
Chenachene
PosteMauriceCortier
Ti-n-Zaouâtene
Bordj lePrieur
Kenadsa
Algeria
LambertConformalConicProjection,SP20N/36N
International boundary
National capital
Railroad
Road
Track
0
100
200Miles
0
100 200Kilometers
Photogrammetric Engineering & Remote Sensing
Vol. 85, No. 7, July 2019, pp. 475–478.
0099-1112/19/475–478
© 2019 American Society for Photogrammetry
and Remote Sensing
doi: 10.14358/PERS.85.7.475
