Page 332 - 360.revista de Alta Velocidad - Nº 5

Mayoral, Juan. Jiménez, Pablo Lorenzo. Fernández-Sánchez, Gonzalo. Jardí, Ignacio.

- Contamination:

As mentioned in previous chapters, the application of satellites used in pollution control
in industrial or urban areas is not applicable to railway systems, since there are no large
concentrations.
- Control of surface movements:

Satellites studied reach precisions below the centimetre in the vertical axis, making possible
the monitoring of superficial movements in earthworks. This control in traditional maintenance
is done by sending surveyors to areas where there have already been appreciable movements
by the human eye. This way of operating has a high cost and sometimes the control comes too
late causing great deterioration in the road.

4. Conclusions

There is a need to find alternative cost-saving alternatives to traditional maintenance, which
uses sometimes expensive methods, such as the use of surveyors and pedestrians. They also
cannot detect certain deficiencies in the railway infrastructure.
The development of aerospace technology, and specifically artificial satellites, introduces the
possibility of an improvement in the control of different elements of the railway platform. These
systems allow us to obtain resolutions of up to 0.25 meters, in the case of optical satellites,
which we can consider sufficient for the measurement of some important distances in the
maintenance like the shoulder of ballast The mentioned resolution together with the possibility
of obtaining the colour of each pixel of the image allows the detection of the existence of
obstacles or fallen elements in the surroundings of the railway platform, in the elements of
superficial drainage or in the own railway infrastructure.

The presence of damp areas that indicate a malfunction of the drainage systems and the
accumulation of water in undesirable places can be detected, by means of the control of the
colour changes, thus facilitating the improvement in the prevention of possible problems in
these systems. In addition, this capacity allows us to perform a better control of the existing
vegetation, optimizing the planning of the works of weeding and irrigation of herbicides,
and with that of the resources available for these works. Another important application of
highresolution colour imaging is the control of the existence of wildlife, such as rabbits, that
can deteriorate the state of the embankments, leading to landslides.
On the other hand, satellites based on radar technology offer the ability to measure vertical
subcentimetric movements, giving the possibility of control of slopes and embankments in
problem areas.

5. References

• ACEX. (2007). Documento base del estado del arte de la conservación de infraestructuras
en España.
• AIRBUS. (29 de Febrero de 2012). La interferometría con radar de apertura sintética.
Recuperado el 1 de Agosto de 2016, de Airbus. Denfense and Space: http://www.space-
airbusds.com/es/noticias-articulos/la-interferometria-con-radarde-apertura-sintetica.
html
• Canadian Space Agency . (10 de Julio de 2015). Satellite Characteristics. Recuperado el
Agosto de 2016, de Canadian Space Agency: http://www.asccsa.gc.ca/eng/satellites/
radarsat/radarsat-tableau.asp

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