Documentation found on the map is written in both Arabic and
English languages, these are mainly street names, descriptions
of area status, and construction. Many other related data have
been registered on the maps such as the map sheet number, a
mapping scale, and control network coordinate values. Non-the-
less, useful index of map grid and map symbols can be found on
each map segment. Figure 3, shows an analogue map sheet of
the city of Tripoli.
These maps of Tripoli, undoubtedly -at that time- have had
surpassed in their technical quality and content all other maps
prepared previously about the city. At the same time and since
then, the city has gone through many large scale changes that
made these good quality maps obsolete, rendering them to an
unsuitable tool in the revision study of the Metro Network.
Figure 1. Schematic representation of Tripoli Metro Network
sg. 44-1
LAYOUT OF THE TRIPOLI METRO METWORK
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Figure 2. Planned layout of Tripoli Metro Network
Following practices of the time, many buildings and
establishments were not shown on that map, a fact in itself
devaluated the usability of the map for such a study. The
technical basis of the map also became old and not very usable,
knowing that the ELD79 datum severely limits the applications
of GPS-based measurements. Nonetheless, although the map
segments have been scanned and put in a coordinates system,
which in theory transfer them to be used as a kind of computer-
based raster map, the resulting product falls short of modern
time standards and our expectations and requirements.
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B7, 2012
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia
2. BASE MAP OF THE TRAFFIC STUDY
To carry out the Revision of the Metro Network Study, and
especially to facilitate field work, there was a natural need to
acquire an up-to-date mapping material. At the beginning of the
revision work, it was unknown whether the contracting partner
(RPEMB) will be able to provide the reviewing teams with such
mapping material, and if so, what kind of quality; therefore the
decision was made to look for a high quality and an up-to-date
geographic data source where computer assisted design and
modern technology can be efficiently applied. To satisfy the
above mentioned criteria, the choice fallen on the CitySphere
satellite image products of Tripoli. Figure 4, shows satellite
mosaics covering the whole Metro planning area.
Figure 4. Satellite mosaics of Tripoli
