Page 467 - 360.revista de Alta Velocidad - Nº 6

Atlas-rail: geo-referenced database on high-speed

values used. A larger scale is recommended to digitize sections with small-radius curves,
in order to improve the accuracy about the real track. As a general idea, interval between
consecutive points from 50 to 200 meters will be considered.
Sections are line segments of variable length with homogeneous technical and service
characteristics, and they can have intermediate nodes. Both lines/sections in service and under
construction are included in Atlas-Rail project.

The characteristics of the sections are called attributes, and they are shown in tables or
databases through fields (columns). Each field has a number of specific characteristics, relating
to accepted data format, interval of values, limited digits or text characters, and so on.
Each line or section is identified with a single code. This code must have unless one digit and it
can be used to join or relate several tables or databases. This issue will be explained in detail
in the following section.

In the case of nodes, the station reference point is always fixed with X, Y and Z coordinate
values, and it is placed in the location of the passengers building. If no passengers building is
found, reference point must be fixed close to the high-speed station.

Figure 1: Example of high-speed line scanning. Olmedo-Zamora HSR (Spain)

Source: Independently produced. Satellite image provided by IBERPIX
(http://www.ign.es/iberpix2/visor/)

2.2 GIS components

GIS can be defined as software with specific capabilities, which are summarized in the following
functions:
In first place, the functions for inputting data. These are the procedures that allow the
conversion of geographic information from analogical (the traditional format in Geography,
especially paper maps) to digital format. This conversion has to keep the baseline features
of the spatial data through data entry procedures (digitizing or similars).

International Congress on High-speed Rail: Technologies and Long Term Impacts - Ciudad Real (Spain) - 25th anniversary Madrid-Sevilla corridor 465