XXII International Cartographic Conference (ICC2005) ISBN: 0-958-46093-0

A Coruña, Spain, 11-16 July 2005 Hosted by:

The International Cartographic Association (ICA-ACI) Produced by Global Congresos

THE USE OF HIGH RESOLUTION SATELLITE IMAGERY IN BACKGROUND STUDIES FOR LINEAR WORKS

Fernando Rodríguez, Ángel González, Mª Luz Gil, David Mariñas and Eduardo Corbelle

Fernando Rodríguez: Department of Linear Works. Proyfe, S.L. fernando.rodriguez@proyfe.es Ángel González: State Road Planning Department in Galicia (Ministry of Development and Public Works)

agdelrio@mfom.es Mª Luz Gil: Department of Agroforestry Engineering, University of Santiago de Compostela. mlgild@lugo.usc.es

David Mariñas: Toponort toponort1@toponort.es Eduardo Corbelle: Department of Agroforestry Engineering, University of Santiago de Compostela.

eduardo.corbelle@gmx.net

The aim of this paper is to determine and assess the current potential of satellite imagery in the field of civil engineering, and more specifically, in the drawing up of background studies for linear works. In order to do this, we have analysed the degree of precision required in order to obtain the base cartography, in accordance with the definition process of a linear work. Additional aspects are also discussed, including economic feasibility, the time periods involved and versatility, comparing them with other techniques currently in use. Our analysis is based on work carried out using a stereo image obtained from the Ikonos satellite, which was then compared with the cartography obtained from more conventional methods. Over the next few years, satellite imagery will replace conventional aerial photography as the principal source of cartographic data, in keeping with the scales required for these types of works. INTRODUCTION Object and Scope In recent years Remote Sensing has practically caught up with Photogrammetry in terms of resolution for medium scales. The latest generation of satellites are capable of obtaining images of a specific zone from various angles, thereby providing a stereoscopic vision and consequently a restitution-based relief. Obtaining imagery in a range of varying spectral bands and with a broad radiometric resolution facilitates thematic mapping.

In addition, the study of alternatives for linear projects is becoming increasingly important in the field of civil engineering. Roads and railways constitute the major types of linear works, yet this area also extends to the following infrastructures: canals (supply or irrigation), electrical power lines (high or medium voltage) and other underground, underwater or aerial channels (oil pipelines, outlets, fibre optics, telephone cables, etc.). These studies enable us to select the optimum route possible for each infrastructure, and to analyse a series of aspects such as environmental impact, adaptation to the relief, functionality, financial cost, etc.

Photogrammetry represented a major step forward in alternative studies, since it offered a greater scope without any significant increase in the amount of fieldwork involved. The possibilities for the restitution of the zones selected during the photogrammetric flight and the availability of imagery that allows the land to be interpreted enables us to provide an assessment of their scope.

To date, the principal drawbacks involved in the use of satellite imagery have been poor resolution, a lack of widespread commercial availability and stereoscopy. Thanks to recent advances in very high resolution Remote Sensing, the time has come to determine whether satellites may now be used as the principal cartographic source in drawing up studies and projects for linear works.

In order to study this hypothesis we intend to compare both processes in a single test area. The experiment was planned as follows: firstly we selected the satellite image that best adapted to our intended aims; we then identified a zone with a recent photogrammetric flight for the drawing up of the base cartography for a linear work project; and finally, once the image had been obtained, we carried out the corresponding comparisons.

Before discussing the results obtained, we have opted to offer an overview of the principal characteristics of linear work Projects and the cartography applied to them. We have dealt mainly with those aimed at establishing new road and

railway routes, not only because they are currently the most common type of projects undertaken, but also because they have been widely regulated and often lay down the guidelines for other similar projects.

Moreover, we have analysed the offer of very high resolution satellite imagery available on the market today. This analysis allows us to select the image or images that provide the degree of precision required in drawing up linear work Studies.

The process involved in obtaining the base cartography required for drawing up linear work Studies using satellite imagery is tested by means of its practical application. In addition to the degree of precision obtained, the final comparison also analyses other aspects such as financial feasibility, time periods and versatility, comparing them with the other techniques currently in use.

Background Attempts to obtain three-dimensional details of the Earth’s surface from remote sensors in space date back to the early experiments using manually operated cameras during the Gemini and Apollo space missions during the mid 1960s and early 1970s, and in a more systemised manner, to the initial experiments carried out using the Earth Terrain Camera situated on board the SkyLab space station in 1973 and 1974 (Toutin, 2001). However, the use of this type of imagery was limited strictly to experimental and scientific fields due to its limited availability and relatively low quality. The generalised use of digital sensors on board unmanned platforms was to make up for the deficiencies of earlier systems, and opened up the possibility of obtaining stereoscopic image pairs of the following two types:

? ? Stereoscopic image pairs obtained from the same orbit. ? ? Stereoscopic image pairs obtained from different orbits.

Whilst the second option was most widely used during the 1980s and 1990s (using images from Landsat, SPOT and IRS-1C/D, which suffered from a lack of stability and poor sensor calibration, thereby preventing their widespread usage), current trends are directed more towards obtaining stereoscopic image pairs from the same orbit (JERS-1, MOMS, ASTER, IRS-P5 and QuickBird). The IKONOS satellite is a special case due to its ability to obtain stereoscopic image pairs from both the same orbit and from adjacent orbits (Toutin, 2001). One of the advantages of image pairs obtained from the same orbit is the greater degree of correlation between the images, due to the shorter time lapse between each image (Toutin, 2004a). Another factor which affects the degree of precision of the heights obtained from the stereoscopic image pair is the angle formed by the visuals: the wider the angle, the greater the degree of precision. This factor is represented by the relation that exists between the distance between the satellite position at each shot and its orbital height (B/H relation) for which values between 0.6 and 1.2 are recommended (Light et al., 1980).

In order to obtain accurate altimetric data the images must have been subjected to the lowest possible number of prior corrections: ideally, they should only have been subjected to the radiometric correction for sensor calibration and normalisation (level 1A) (see Piwowar, 2001 for an explanation of the various correction levels). Alternatively, pre-georeferenced imagery may also be used (level 1B), using systematic geometric correction, although this tends to produce lower quality results (Toutin, 2.001). In addition, the choice of image correction level will also affect the planimetric precision obtained, another important parameter to be taken into consideration when assessing its application for the generation and/or updating of cartography.

A look back at recent works carried out using IKONOS imagery reveals that it is possible to obtain altimetric data with a precision of 1.5 m (Root Mean Square Error, RMSE), which allows for the generation of 5 m equidistant level curves, (typical of the 1:5000 scale (Toutin, 2004a). It is also possible to automatically generate digital elevation models, although depending on the type of land surface the degree of precision may fall to 6.4 m (RMSE) (Toutin, 2004a). Other works, such as those of Eisenbeiss et al. (2004), refer to degrees of altimetric precision of between 1-5 m for automatic extraction, and the possibility of obtaining a degree of precision of 0.5 – 1 m (RMSE) in the case of manual extraction.

The degree of planimetric precision also depends on the type of image obtained. The best results are obtained using the IKONOS Geo Product image and a physical (parametric) orthorectification model (Toutin, 2004b). Under these conditions, it is possible to obtain a degree of precision of 1.3 m (Toutin et al., 2002), 0.9 m RMSE (Vassilopoulou et al., 2002), or even 0.3-0.6 m RMSE (Fraser et al., 2002), provided that there are control points featuring decimetric precision.

BACKGROUND STUDIES Linear Work Studies In Spain, Road Act 25/1998, dated 28 July, defines the various types of Studies, in accordance with their end function:

- Planning Studies: these consist of defining a road plan for a specific horizon year. It also includes recommended features and sizes, land requirements and other restrictions, for the purpose of land and transport planning.

- Background Studies: these consist of collecting and analysing all necessary data in order to offer a general definition of the various solutions for a specific problem, taking into account all possible implications. Informative Studies: these consist of the general definition of the road route and layout, thereby serving as a basis for any possible public information records.

- Feasibility Studies: these consist of an appropriate scale study and assessment of the best solutions to a specific problem, thereby enabling the optimum solution to be determined.

- Construction Projects: these consist of the full development of the optimum solution, including sufficient detail in order to ensure the feasibility of both the construction work and consequent operations.

- Route Projects: these sections of the constructions projects include geometric aspects and considerations, as well as specific details of the affected assets and rights.

In turn, the Railway Act 39/03, dated 17 November, states that: ? ? For the purposes of creating or modifying a line or stretch included in the Railway Network, prior

approval of the corresponding Informative Study must be obtained from the Ministry of Public Works, pursuant to the terms and condition of this Act and the corresponding regulations. The Informative Study must include the geographical and practical definition and analysis of the various route options for a specific action, and, where relevant, of the selection of the most recommendable alternative. The Informative Study shall include an Environmental Impact Study for all the options put forward and shall constitute the basic document for the purposes of the corresponding environmental appraisal pursuant to existing legislation for the protection of the environment.

? ? The Construction Project is defined as that which specifies the full development of the solution adopted in order to meet the need for a specific railway infrastructure. It shall include sufficient details in order to guarantee the feasibility of its construction and consequent operation. The Basic Project is that part of the Construction Project that specifies the geometric aspects and considerations involved, as well as specific details of the affected assets and rights.

In short, both the new road and rail works are normally included within a state or regional Infrastructure Plan. The Public Information process is based on an Informative Study, and specific details of the work involved are included at a later stage in the Route and Construction Project. The Informative Study includes the Environmental Impact Study and a thorough analysis of all possible alternatives, based on the Environmental Impact and Public Information Declaration.

The Route Project includes a full geometric definition and is used to initiate the Expropriation Report, which is drawn up whilst the Construction Project is being concluded. In the event of the existence of a road or rail reserve in the plans for the affected municipalities, and depending on the type of work required, the Public Information and Environmental Impact Report may be assessed, together with a Route Project, as the alternatives will be limited to a predefined corridor.

Linear Work Studies use cartography on various scales, although the following are the most commonly used options: ? ? Informative Studies 1:5000 ? ? Route and Construction Project 1:1000

Today, the vast majority of Studies and Projects for linear works are drawn up using digital cartography and computer assisted design (CAD) systems. However, in all cases the degree of precision in cartography depends on the work scale and must not be confused with the degree of precision used in the various operations and measurements of CAD software. The methodology used for the purposes of obtaining the base cartography for the Study must focus on obtaining the degree of precision necessary for the final work scale.

It is known that the required degree of precision of a map is inextricably linked to the visual perception limit (0.2 mm). Consequently, the degree of precision necessary when drawing up specific cartography for linear work projects is as follows:

? ? Informative Study 1.0 m ? ? Route and Construction Project 0.2 m

The standard procedure for drawing up the base cartography consists of carrying out a photogrammetric flight, the back up of stereoscopic image pairs (or alternatively the block acquired from aerotriangulation), scanning the photograms and the digital restitution of the area under study.

The resolutions used (size of the photographic grain and pixel size of the scanned image), together with the degree of precision at the support points, must guarantee the determination of an element (such as the corner of a house) within the degree of tolerance required, depending on the desired scale.

As a result, the images used are taken from photogrammetric flights that meet the following conditions: Flight Scale Resolution

? ? Informative Study 20000 0.42 m ? ? Route and Construction Project 5000 0.11 m

In the light of these data and as shown in the following section, the satellite imagery that is currently available on the market still fails to meet the degree of precision of those obtained from a plane for the scales mentioned, although Quickbird, OrbView-3 and Ikonos on a scale of 1:5000 in the Informative Studies come close.

Nevertheless, this only affects the degree of precision at a specific point of the terrain (such as the corner of a house); elements may be determined with a lesser degree of precision, since in an Informative Study it is more important toe discover the real layout of the terrain (such as the presence of a house) than the actual degree of precision itself. The Route and Construction Projection provide an exact definition of the work to be carried out, and it is at this stage that the degree of precision of the base cartography must meet the requirements specified above.

A further aspect for consideration is that digital cartography on a scale of 1:5000 of much of the terrain already exists, thanks to the work of various official organisations including Autonomous Regional Governments and Cartographic Associations and Institutes, etc. Existing cartography may be acquired directly and used as the basis for the various Studies; although in most cases it will require updating by means of a new photogrammetric flight, back up and restitution, etc.

Assuming the existence of previous cartography that fully complies with all the necessary quality standards, any updates required for the drawing up of a Study may be made with a lower degree of precision, as the most important aspect when studying alternatives is the correct interpretation of the current situation of the terrain involved.

Moreover, certain thematic maps do not require the degree of precision necessary for obtaining the base cartography, due to the lack of determination of the limits of its coverage; this includes maps of vegetation, wildlife, landscapes, land usage, etc.

It may therefore by considered that the degree of precision required in the cartography used for the purposes of drawing up an Informative Study permits the use of very high resolution satellite imagery. Obtaining cartography or updating existing cartography should be based on stereoscopic images (panchromatic or colour) with a resolution equal to or greater than 1.0 m. In the case of thematic mapping, lower resolution imagery (e.g. 5 m) may be used.

High resolution satellite imagery Figure 1 shows the technical features of the satellites which currently obtain very high resolution imagery and the various products offered by each.

The Quickbird satellite offers the best geometric and radiometric resolutions, yet the stereoscopic product is not available on the commercial market, and consequently its imagery can only be used to update existing planimetric cartography. The procedure involved would be based on obtaining the digital earth model (DEM) from existing cartography, the creation of the corresponding orthophotography and later digitalisation.

Ikonos is the satellite which currently offers the best solutions for the aspects mentioned, as it includes a standard stereoscopic project and suitable resolution in both panchromatic (1.0 m) and multispectral (4.0 m) mode. Ikonos is capable of obtaining images of a specific area every three days, which allows for the localisation of the area of interest under favourable weather conditions in a short period of time (the satellite’s list of tasks must also be taken into consideration).

Satellite Geometric resolution Radiometric resolution Sweep Stereo

0.61 m (P) Quickbird 2.44 m (XS) 11 bit 16.5 Km Yes (*)

1 m (P) Ikonos 4 m (XS) 11 bit 13 Km Yes

1 m (P) OrbView-3 4 m (XS) 11 bit 8 Km Yes

Eros 1.0 / 1.8 m (P) 11 bit 9.5 / 13.5 Km Yes 2.5 m (P) Spot 5 10 m (XS) 8 bit 60 a 120 Km Yes

5.8 m (P) 6 bit IRS 23 (XS) 7 bit 70 a 810 Km No

Figure 1. Overview of very high resolution satellites. (*) Not available on the commercial market

Ikonos or Quickbird imagery is available in a radiometric resolution of 11 bits per pixel, which allows us to work with a palette of 2,048 real grey tones. Although the visualisation systems only show 256 tones, and the human eye itself is unable to distinguish more than this number, this information is of vital importance in both thematic mapping and in correlation treatments (aerotriangulation, automatic digital modelling, etc.).

MATERIAL Our starting point is a satellite image with the following characteristics: an orthorectified, panchromatic (P) and multispectral (XS) stereo image from the Ikonos satellite, georeferenced in Reference mode (25.4 m CE90), obtained by SpaceImaging on 14 April 2005. The images are provided in GeoTiff images with a radiometric resolution of 11 bits per pixel and associated ASCII file. The image pixel size is 1.0 m. The region the image corresponds to is located in Ferrol (A Coruña – Spain), and covers an area of approximately 100 sq. km.

The official Cartography of Galicia on a scale of 1:5000 in digital format (drawn up by the Autonomous Government– Xunta de Galicia) was used for the purpose of comparing the results obtained by means of the satellite image, as was the digital format of the cartography on a scale of 1:500 of the Magdalena District of the city of Ferrol. The aim was to use the former to compare the results at the desired level of precision and the latter as a means of comparing total precision.

Given that the image has a low level of georeferentiation, it was necessary to find several points of support. These are observed thanks to the use of GPS techniques which guarantee the following degrees of precision: RMSx, y < 0.05 m y RMSy < 0.1 m.

Figure 2. Scope of the image acquired by Ikonos (14-04-05)

METHOD Prior digital treatment consists of lineally highlighting the original bands. Later the panchromatic channel and the 3/2/1 (R/G/B) composition of the multispectral channels were combined using the IHS method. The cylindrical algorithm and cubic corrected image were used.

In the following procedure the Intergraph ISPM (Image Station Photogrammetry Manager) was used, whose work flow is shown in Figure 3.

Figure 3. Work process based on satellite image

An initial project is created to convert the photos from their native format (TIF or NTIF) to low compression JPG images or TIF files. In order to do so tools from the Z/I Imaging series are used, applying the various resources available for handling the photogrammetry images (the creation of TILES and OVERVIEW pyramids).

At this stage the type of co-ordinates system is selected, two of which may be defined: one for the restitution of cartographic elements (in UTM projection) and another for visualisation in geographical co-ordinates. The work units are also defined, based on the scale of the end product. The models with their respective images are then created, and the control or support points are then imported for enhanced precision.

It is now possible to process the aerotriangulation and correlation work, just like in any other photogrammetric project. The degree of precision obtained for the purpose of making the calculation will depend on the precision of the control points. At this stage the project may now be used for the restitution of land elements, automatic digital models, orthophotomaps, etc. When defining the scale of the end product, the degree of precision obtained in the various triangulation processes and the appreciation capacity (pixel size) of the original image must also be taken into consideration.

In this case a total of 16 support points were used, and the following degrees of precision were obtained after making the corresponding external orientation of the stereoscopic image: RMSx= 0.042 m, RMSy= 0.031 m and RMSz= 0.012 m.

Once the model has been oriented, restitution may now commence using the same work method and tools as used in conventional photogrammetry. Restitution is carried out on a series of elements which may be used to compare the data obtained from the cartography on a scale of 1:5000 (hereinafter referred to as sample zone 1) and the cartography on a scale of 1:500 (hereinafter referred to as sample zone 2).

Ten identifiable points were measured in each sample zone (principally the corners of buildings) in both the new image and the existing cartographies.

RESULTS The results obtained in both sample areas are shown in the following charts and figures:

SAMPLE ZONE 1 No. of points Average (m) SD (m) Max Error (m) Planimetry (X, Y) 10 0.146 0.304 0.980 Altimetry (Z) 10 0.257 0.116 0.484

Figure 4. Results based on a comparison with 1:5.000 cartography

Figure 5. Restitution and comparison based on 1:5000 cartography

SAMPLE ZONE 2 No. of points Average (m) SD (m) Max Error (m) Planimetry (X, Y) 10 0.182 0.322 1.344 Altimetry (Z) 10 0.182 0.266 0.879

Figure 6. Results based on a comparison with 1:500 cartography

Figure 7. Restitution and comparison based on 1:500 cartography

DISCUSSION We must start by stating that the request for the image was made on 28 February 2005, and a maximum period of 2 months was established in order to obtain the image. Forty-five days elapsed between placing the request for the image and its actual acquisition. It must also be stated that weather conditions in the area at that time of year tend to be somewhat adverse, and this period would probably be shorter during the summer months or in another region with more favourable weather conditions.

In comparison with photogrammetry, considerable delays in carrying out the flight may occur (delays which may be up to several months during winter). This is due to the fact that several tasks are carried out on the same day, thereby requiring favourable weather conditions for a large area.

Despite the positive results obtained, it must also be said the check or control points were selected amongst those offering the highest levels of definition and clarity. Many of the elements restituted using the Ikonos stereoscopic imagery failed to coincide with those in the sample zones, a fact which is directly related to the spatial resolution of the image. It can therefore be concluded that 1 metre spatial resolution of stereoscopic imager is still not appropriate for use in drawing up cartography on a scale f 1:5000.

When considering its use as an alternative to conventional photogrammetry, a further major aspect must also be taken into consideration, namely cost, which is summarised in the table below:

Image €/Ha Scanned

€/Ha Highlighting

€/Ha Support

€/Ha A.T. €/Ha

Restitution €/Ha

1:18000 Scale flight 0,18 0,030 - 0,20 0,030 0,6

1:30000 Scale flight 0,12 0,015 - 0,15 0,015 0,6

Ikonos stereo (P) 0,61 - 0,01 0,06 0,010 0,6

Ikonos stereo (P+XS) 0,69 - 0,01 0,06 0,010 0,6

Figure 8. Estimated prices based on model surface.

As can be seen from the table in Figure 8, the field support is considerably reduced in the case of the satellite image, as the number of orientation points needed is lower, due the to fact that the entire zone is considered as a single stereoscopic pair. Likewise, the costs involved in aerotriangulation are also lower, whilst the cost of restitution remains the same.

With regard to the time needed for the preparation of models and orientation etc., the process is slightly slower in the case of conventional photogrammetry. This is due to the fact that semiautomatic processes are used, whilst in the case of satellite imagery the entire procedure is automatic.

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10 50 100 200 300 400 500 600 700

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t (€)

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Figure 9. Line graph comparing cartography costs based on initial image type

In general terms, the use of satellite imagery for a scale of 1:5000 is one and half times more expensive than conventional procedures for an optimum surface area of around 100 sq. km.

So far we have considered the relative costs involved in obtaining base cartography, yet the other advantages satellite imagery offers must also be taken into consideration. The information contained in each of the spectral bands can be used to create the thematic maps necessary for the various tasks involved in drawing up an Informative Study, such as land usage, hydrology, vegetation , landscape, environmental assessment (in synthesis with the others), etc.

Bibliographies, collections of official maps (most of which are obsolete), photo interpretation (based on flight photograms) and various field studies are currently used in order to create the majority of the thematic maps needed for Informative Studies and Environmental Impact Studies. As shown in Figure 9, failing to resort to the use of multispectral data does not represent any significant savings, particularly if we consider the potential possibilities this method offers.

For this reason, the increase in cost is less than initially expected and should be considered in terms of the overall project.

CONCLUSIONS The principal conclusion we have obtained is that 1 metre spatial resolution stereoscopic imagery is still not appropriate for creating cartography on a scale of 1:5000. This is due to the fact that the photo interpretation of the elements subject to restitution does not offer the required geometric quality. Furthermore, the current cost of such imagery makes it unfeasible for use in cartographic updating. However, our attention must also be drawn to a series of positive aspects: the speed with which the images are obtained, reduced field work time, reduced processing time and the possibilities of thematic mapping. All that is required for satellite imagery to replace aerial photography in this kind of work is a slight increase in resolution levels and a further reduction in the costs involved.

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Fraser, C., Baltsavias, E., Gruen, A. (2002). Processing of Ikonos imagery for submetre 3D positioning and building extraction. ISPRS Journal of Photogrammetry and Remote Sensing, nº 56.

Light, D.L., Brown, D., Colvocoresses, A., Doyle, F., Davies, M., Ellasal, E., Junkins, J., Manent, J., McKenney, A., Undrejka, R., Wood, G. (1980). Satellite photogrammetry. In: ASPRS. Manual of Photogrammetry (Chapter XVII), Bethesda, USA, pp. 883-977.

Piwowar, J. (2001). Getting your imagery at the right level. Cartouche, Newsletter of the Canadian Cartographic Association, nº 41.

Toutin, Th. (2001). Elevation modelling from satellite visible and infrared data: a review. International Journal of Remote Sensing, vol. 22, nº 6.

Toutin, Th. (2004a). DTM generation from Ikonos in-track stereo images using 3D physical model. Photogrammetric Engineering and Remote Sensing, vol. 70, nº 6.

Toutin, Th. (2004b). Geometric processing of remote sensing images: models, algorithms and methods. International Journal of Remote Sensing, vol. 25, nº 10.

Toutin, Th., Chénier, R., Carbonneau, Y. (2002). 3D models for high resolution images: examples with QuickBird, IKONOS and EROS. Proceedings of the Symposium on Geospatial Theory, Processing and Applications, Ottawa, Canada.

Vassilopoulou, S., Hurni, L., Dietrich, V., Baltsavias, E., Pateraki, M., Lagios, E., Parcharidis, I. (2002). Orthophoto generation using IKONOS imagery and high resolution DEM: a case study on volcanic hazard monitoring of Nisyros Island (Greece). ISPRS Journal of Photogrammetry & Remote Sensing, nº 57.

Gutiérrez del Olmo, J., Moreno, M. (2.000). Pasado Presente y Futuro de la Teledetección de Alta Resolución. El Satélite Ikonos. Mapping.

Dial, G., Grodecki, J. (2.003). Ikonos Stereo Accuracy Without Ground Control. ASPRS 2003 Annual Conference Proceedings.

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Ley 25/1988, de 28 de Julio, de Carreteras.

Pliego de Cláusulas Administrativas Particulares. Contrato de Consultoría y Asistencia para la redacción de un Estudio Informativo. Dirección General de Carreteras. Ministerio de Fomento. 2.003.

Ley 39/03, de 17 de Noviembre, del Sector Ferroviario.

Pliego de Cláusulas Administrativas Particulares. Contrato de Consultoría y Asistencia para la redacción de un Estudio Informativo. Gestor de Infraestructuras Ferroviarias (G.I.F.) 2.003.

www.imagesatintl.com

www.spaceimaging.com

www.spotimage.fr

www.mundofree.com/igomenor/homesats.htm

www.aurensa.es

BIOGRAPHY Name: Fernando Rodríguez Fontán.

Date and place of birth: 05-11-72 Ferrol (A Coruña, SPAIN).

Nationality: Spanish.

Profession: Geodetic and Cartographic Engineer.

Professional Experience: From 1996 to the present: Proyfe, S.L. (Engineering and Construction Projects).

Qualifications:

? ? Topographic Engineer. Universidad Politécnica de Madrid (July 1996).

? ? Geodetic and Cartographic Engineer (specialising in Geodesics and Geophysics). Universidad Politécnica de Valencia (July 2002).

? ? Lecturer for the PhD programme in Agroforestry Engineering (area of Cartographic Engineering, Geodesics and Photogrammetry) at the University of Santiago de Compostela (July 2004).