Role of satellite remote sensing in the geographic information economics in France

ISPRS Journal o f Photogrammetry and Remote Sensing, 46 ( 1991 ) 359-370

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Elsevier Science Publishers B.V., Amsterdam

Role of satellite remote sensing in the geographic information economics in France Jean Den6gre Conseil National de 17nformation Gkographique 136 bis, rue de Grenelle, 75700 Paris, France (Received 20 November 1990; revised and accepted 29 June 1991 )

ABSTRACT Denbgre, J., 1991. Role of satellite remote sensing in the geographic information economics in France. ISPRS. J. Photogramm. Remote Sensing, 46: 359-370. In national and international economics, geographic information plays a role which is generally acknowledged to be important but which is however, difficult to assess quantitatively, its applications being rather miscellaneous and indirect. Computer graphics and telecommunications increase that importance still more and justify many investments and research into new cartographic forms. As part of its responsibility for participating in the promotion of those developments, by taking into account needs expressed by public or private users, the National Council for Geographic Information (C.N.I.G.) has undertaken a general evaluation of the economic and social utility of geographic information in France. The study involves an estimation of the cost of production and research activities, which are probably about 0.1% of the Cross National Product--similar to many other countries. It also devised a method of estimating "cost/advantage" ratios applicable to these "intangible" benefits. Within that framework, remote sensing emphasizes particular aspects related both to the increase of economic performances in cartographic production and to the advent of new products and new ways of utilization. A review of some significant sectors shows effective earnings of about 10-20%, or even 50% or 100% of the costs, and these are doubtless much greater for the efficacy in the exploitation of products. Finally, many applications, entirely new result from extensions in various fields which would have been impossible without remote sensing: here the "cost advantage" ratio cannot even be compared with previous processes. Studies were undertaken in parallel for defining different types of products derived from satellite imagery, as well as those domains where development effort is required in order to make new advances.

RI2SUMI2 L'information g6ographique joue dans l'6conomie nationale et internationale un r61e dont l'importance est g6n6ralement reconnue pour le d6veloppement, mais qui reste difficile ~t quantifier, tant ses applications sont diverses et diffuses. L'informatique et la t616matique accroissent encore cette importance, qui 16gitime de nombreux investissements et travaux de recherche de nouvelles formes cartographiques. Charg6 de contribuer a promouvoir ces d6veloppements en tenant compte des besoins ex-

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© 1991 Elsevier Science Publishers B.V. All rights reserved.

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prim6s par les utilisateurs publics ou priv6s, le Conseil National de l'Information G6ographique (C.N.I.G.) a entrepris une 6valuation g6n6rale de l'utilit6 6conomique et sociale de celle-ci au niveau frangais. Cette 6tude passe par une estimation des coots engag6s dans les activit6s de production et de recherche, dont l'ordre de grandeur se situe autour de 0.1% du Produit Int6rieur Brut au niveau mondial, ainsi que dans l'61aboration d'une m6thode de type "coflts/avanrages" applicable/l ce patrimoine "immat6riel". Dans ce contexte, la t616d6tection apporte un 6clairage particulier, li6/t la fois ~ l'augmentation des performances 6conomiques en production cartographique et/l l'apparition de nouveaux produits et de nouveaux modes d'utilisation. Un panorama de quelques secteurs significatifs montre des gains effectifs sur la production classique de l'ordre de 10% ~ 20%, voire/t 50% ou 100% dans les coots, et sans doute tr~s sup6rieurs dans l'efficacit6 de l'exploitation des produits. Enfin, de nombreuses applications, enti~rement nouvelles, traduisent une extension du secteur qui n'aurait pas 6t6 possible sans la t616d6tection: ici le ratio avantages/cofits devient hors de comparaison avec les processus ant6rieurs. Parallblement, des 6tudes sont entreprises pour d6finir les diff6rents types de produits d'origine satellitaire, ainsi que des domaines o/l l'effort de d6veloppement doit ~tre intensifi6 pour de nouveaux progrbs.

1. INTRODUCTION

In national and international economics, geographic information is generally acknowledged to play an important part in development, however, the exact role it plays is difficult to assess quantitatively, its applications being rather miscellaneous and dispersed. It can, however, be characterized by the amount of the relevant budget. An additional, but indirect, assessment is provided by the economic performance of spatial remote sensing, compared with conventional techniques. The economic advantages of satellite mapping have already been demonstrated by international experts such as G. Konecny (1990), and the purpose of this paper is simply to contribute to the demonstration. The economic weight of cartographic production all over the world has been the subject of several studies, the main one being that of the U.N. (1987). They show the volume and limitations of the efforts deployed by most countries for obtaining adequate geodetic and levelling networks for development purposes (Table 1). The modernization of map-production gave rise many years ago to the "geographic information" concept embodied in ground-referenced data bases which are likely to replace maps increasingly in the future. Maps are only their expression in a graphical form, in a way the "tip of the iceberg". That extension confers an increasing importance to corresponding activities: the need for improved knowledge of the leading economic, financial and social

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TABLEI Expenditure devoted to basic national* topographic mapping, by continent, in 1980 (extract of the report presented by the Secretariat of the U.N. Economic and Social Council at the Bangkok Conference in January 1987 ) Continent

Africa N. America S. America Europe Asia USSR Australasia+Oceania World

Area involved

Corresponding budget

M (km 2)

Percentage of total

Total (US $Million)

Per km 2 (US $)

17.08 21.86 17.32 3.02 18.21 22.40 8.47 108.37

56 90 97 61 66 100 99 80

68.2 128.2 41.6 169.7 142.9 100.0 41.5 692.2

4.0 5.3 2.4 56.1 7.8 4.5 4.9 6.4

Percentage of GNP**

0.066 0.005 0.012 0.013 0.023 -0.065 0.010

*Basic topographic mapping closely defined (cadastral plans excluded ). **Gross National Product (calculated prorata of the areas concerned, per continent).

factors of those activities is being felt in many countries. It has highlighted the need to rationalize both administrative as well as technical procedures in order to improve cooperation between the groups involved and make the best possible choices and take advantage of the available investments. In France, the task of co-ordinating efforts was entrusted to the National Geographic Information Council (C.N.I.G.) set up in early 1986. Its membership reflects the diversity of the parties interested in geographic information: thirteen representatives from government departments, four town councillors, nine representatives from organizations producing geographic information (including the private sector "g6om6tres-experts") and two professional people. The C.N.I.G. Commissions and Working-Groups set up since 1986 have widened that coverage still further with, in particular, the participation of manufacturers. However, the diversity of those partners shows, at the same time, the multiple character of geographic information and the difficulty of defining its scope. In general, "geographic" refers to all the ground-referenced information concerning an entire country. That referencing can be expressed either directly by two- or three-dimensional coordinates, or indirectly by administrative-type location data, such as postal addresses or cadastral parcels, which make reference to the ground or existing plans. With that definition, geographic information covers not only the normal components of map-production (geodesy, aerial photographs, maps, etc.) but also most administrative and socioeconomic files, for example population censuses, so long as they are referenced to some national system which is sufficiently discriminating. In addition, geographic information does not arise as a group of different

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products coming from separate channels, but rather as a network of more-orless finished products with complex fluxes: each geographic product is situated, in one way or another, downstream from other geographic products of which it represents a synthesis, and upstream from other derived products to whose generation it contributes. It even happens that the downstream products contribute reciprocally to the generation or improvement of upstream products; for example, geodesy participates in satellite launching, which, in turn, makes it possible to improve the accuracy of geodetic positioning. One has here an example of a closed-circuit channel. Thus, multi-form and multi-processed, geographic information appears as a diffuse sector of activities where interferences are quite c o m m o n and where the economic implications branch out to infinity. The idea of evaluating its economic and social utility proved to be all that more difficult because it concerned the expression by numbers of all the types of advantages encountered. These must be compared with production costs, whose importance were mentioned at the very beginning of this report. Such precision is the objective of the investigation currently being undertaken by the C.N.I.G. 2. W H I C H E V A L U A T I O N M E T H O D ?

When one asks that question, economists look for methods applied in similar cases in addition rejoin that of information in general. A first discussion 1 ed to distinguishing at least three approaches (based on Didier, 1990). 2.1. Reference to the market

The existence of a real geographic information market would supply a normal economic evaluation tool: the market price. However, the production of geographic information is very largely the responsibility of the State and thus it has a non-commercial character which removes from the market price a large part of its meaning: that which is sold is mainly the service of making the information available in one form or another and not the production of the information itself. As regards the information produced by the private sector, it is generally for its own purposes and is thus rarely made available on the market. Consequently, it is not really possible to assess the utility value of geographic information using the market price. 2.2 Production costs

The second approach consists of starting from the "public asset" character of geographic information and then applying to it the general evaluation rules for non-commercial productions, such as those used in national accounting, i.e. cost-evaluation. That assumes an enquiry into the total expenditure de-

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voted to the production or transformation of geographic information. This specific "reckoning" does not appear in national accounting and must therefore be built up by assembling all the sectors with activities linked to geographic information, which as we have seen, are widely dispersed. That evaluation takes into account the efforts employed at the national level for producing geographic information but it does not express the utility of the latter outside the producing services, i.e. its impact on other economic agents. For example the utility of the cadastre goes beyond its fiscal role for defining rateable values and applies to sectors such as regional development and local authority management: this is precisely the utility which also needs to be evaluated in the proposed investigation. The production costs thus supply part of the reply sought, but only a part of it. 2.3 The "external" uses o f the public asset

By extending the preceding approach, this basically concerns estimating the external economic effects (or "externals") of the public asset constituted by geographic information. A large number of these economic (and social) effects have already been listed during the study, in the form of various utility criteria, classed in three families. They can be stated in brief as: Conceptual level." (i) Basic tool aspect: very necessary for all applications considered as important; (ii) Network aspect: systematic territorial extension, thus easy-access identical in all places; (iii) Scale economy: coordinated programming for production and unified distribution; (iv) Spread economy: federation of multiple uses (the greatest number of partial applications ); (v) Immediacy aspect: immediate availability of the product, thus time saving for downstream uses; regular maintenance of the product thus updated geographic information, giving better effectiveness; (vi) Non-consumable aspect: Non-degradation of the information when using it; (vii) Interactivity aspect: in return, enrichment of the product by the actions of users interested in its improvement; Economic level sensu stricto: (viii) Relative economic aspect: in comparison with replacement solutions, which give rise to much higher costs; (ix) Absolute economic aspect: when no replacement solution is available, disappearance of corresponding applications (Refers to criterion (i) ); (x) Side effect: economic weight linked to the product (applications, instrumentation, marketing, exportation );

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Social level: (xi) Training and communication value: advantages for education and information (professionals and general public ), useful for the media; (xii) Reference value: common language, having authority, polyvalent, e.g. map backgrounds; (xiii) Awareness effect: added value in terms of collective awareness; e.g. regional or national identity, enrichment of general knowledge (scientific, administrative, etc. ); (xiv) Prestige value: aid to influence national culture, sovereignty symbol, reputation, etc. These principles having been listed the problem still remains, however, that these utility criteria only have value insofar as the use that is made of them: a highway plan can have a very great use but if a civil-engineering contractor makes a mistake when reading it and accidently breaks open a drain, the utility value of the plan can be almost zero. It only makes a user fully responsible for his own decisions. Likewise, a general map as intstructive as it may be, looses all its value if it is not widely distributed to the general public. This demonstrates that the utility value of products must be evaluated by analyzing the exploitation methods employed for them that is, by analysis of concrete and significant cases in the different sectors concerned. This also shows that geographic information does not have an absolute value, but has a relative value depending closely on its aptitude to be exploited: in other words, on the forms that it takes, and in particular, its modernization. Viewed from that angle, this approach leads rather to comparing the utility of new products with those of earlier ones, and thus to assist with the choice of the investments to be made for modernization purposes. Most geographic information activity sectors are evidently concerned in this: geodetic networks (with the G.P.S. ), remote sensing (with satellite imagery ), digital cartography (with computer-assisted cartography), data bases (with G.I.S.), documentation (with optical supports: videodisks and D.O.N.), distribution (with computerized transmission ), etc. By way of illustration, we will examine here only a few aspects linked to satellite remote sensing. 3. E C O N O M I C E V A L U A T I O N O F SATELLITE I M A G E R Y P E R F O R M A N C E S

If one examines some of the most significant sectors using remote sensing, it appears that some items are becoming available in the following domains: (i) basic topographic mapping, (ii) geologic mapping, (iii) thematic mapping for development (road networks ). (iv) oceanographic (littoral) mapping. No doubt it is necessary to consider them with care, but one can neverthe-

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less use them as a basis for discussion, and make them more accurate in the future.

3.1. Basic topographic mapping Starting with a certain number of mapping operations undertaken in developing countries (Yemen, Mali, Guinea, Algeria, Djibouti) items for comparison were gathered together, concerning regular line mapping at the 1:50 000 scale either based on SPOT stereoscopic satellite imagery or aerial photographs (A.P.). For the main phases of map production these items lead to the figures given in Table 2 based on a report by Denis and Baudoin ( 1988 ). It should be noted that the costs of field operations are generally higher with satellite imagery, due to the difficulty of identifying certain point and line details. For example, the secondary road network is only partially identified on sPoT imagery with a 10 m resolution and likewise for the detailed hydrographic network. This handicap was also observed on high-resolution satellite photographs (Spiess, 1987 ). The results are, however, very largely positive, because the gains in the first three phases (which total 33-50% of the process) range between 1 (or 2) and 5 (or 6) with a mean value of 3. It is noteworthy, in particular, that in these remarkable economic conditions, the networks obtained by "spatial triangulation" should be so good, having an accuracy compatible with the regularity criteria for the 1:50 000 scale, resulting from the calculation by "segments" of stereoscopic images (belonging to the same orbit, thus more rigid than aerial photography stereoscopic pairs): for example, for 16 scenes distributed over 4 segments, the standard deviations on the residuals of the adjustment gave: For the control points (16) 11 m for x; 9 m for y; 6.6 m for z For the check points (197) 12 m for x; 11 m for y; 6.3 m for z. TABLE 2 Mapping operations used for the economic evaluation of topographic mapping (from data in Denis and Baudoin, 1988) Phase

Weight in the process

k=A.P./SPOT Ratio

3- 5 15-20 15-25 20-30 15-25 2- 5

k = 1 to k = 4 k = 2 to k = 6 k = 3 to k = 5 k-~ 1 k-~ 1 k -~ 1

(%)

Data acquisition Network calculation (triangulation) Photogrammetric plotting Field topographic operations Map editing Copying and printing

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Those figures were obtained by IGN France during SPOT evaluation tests for southern France and result from very careful measurements and calculations. It appears that the quality of those results is confirmed at other sites and thus vouch for the effectiveness of the contribution of remote-sensing applied to basic topographic mapping.

3.2. Geologic mapping and other applications Geologic mapping is not the only application of remote sensing to geology. Others are also important, such as mineral research, hydrologic studies and regional development (geotechnics, littoral geology, etc. ). Within those applications, remote-sensing (R.S.) is distinguished by a very strong integration which makes it difficult to evaluate its economic impact in the processes. In addition, within each application, each study is often a particular case, linked to local and operational conditions. The gains obtained due to remote sensing result mainly in terms of reductions in the times required for specific operations: the improvement of product quality, though having a theoretical economic value, is not a quantity that can be used in practice. Consequently, if one is interested in time gains, the figures given in Table 3 have been published. Although much lower than the gains mentioned previously for basic topographic mapping, those figures nevertheless have a certain economic importance if one refers them to the overall budgets devoted to geology. TABLE 3 Time gained by using remote sensing (R.S.) in geologic mapping Activities

Normal duration (month)

Geologic mapping

3-12

Mineral research (exploration level)

10- 3

Time gain using R.S. (%)

Remarks

10-20

Use of R.S. reduces field working time (proportion very variable ) Quicker marking in potential zones and reduction in exploration times Improvement in drilling site selection Very variable time gains

< 30 in the reconnaissance phase

Hydrogeologic investigations

1- 6

5

Road development

1- 6

5-25

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2.3 Thematic mapping for road network development (The details below were extracted from Auzel et al., (1988)). Since the 1976 French Nature Protection law was passed any medium or large development project must present an impact study before it can begin. That study must conform with the following general requirements: up-to date information, accurate spatial location, expression of the diversity of the environmental themes, combination and evaluation of the constraints. Those requirements are difficult to satisfy with normal techniques because of the short times available for meeting them and the frequently unadaptable nature of the documents available. That is why SPOT satellite imagery appears to be an interesting alternative solution, having a large number of advantages for meeting the above requirements: up-to date information, accuracy, the possibility of thematic interpretation and computer-assisted cartography. A major project was undertaken for the French Ministry of Works (Northern Counties division) by the SEEE-INTER G Group for the bypass road around the town of Maubeuge. The procedure included the extraction of primary thematic plans based on SPOT imagery and other data (road traffic, town planning documents, fauna, flora, geology, etc. ), then the production of eleven cartographic documents by combining those thematic plans (all geocoded) in order to describe the different components of the environment, and finally the production of a map synthesizing the constraints, weighted in accordance with the weights of the themes actually present. One thus obtains a quantitative map and not just a qualitative one, whose presentation can be more instructive for decision makers and the general public. That improvement of the final product was accompanied by improvements in economic performances that the project leader summarized as given in Table 4. It is interesting to note that cases of unsatisfactory aerial photography (esTABLE 4 Improvements in economic performance achieved by using a variety of thematic plans and SPOT imagery Process including SPOT imagery ( 1 )

Using aerial photography (2)

Cost reduction using ( 1 ) Compared to (2)

If already available in catalogue If already available in catalogue If not available (i.e. to be programmed )

If not satisfactory If satisfactory If not available

+ 10% Equivalent Equivalent above 100 km 2

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pecially too old) are very frequent, particularly for wide spread regions or regions of difficult access and, in addition, that the use of satellite imagery favours a design method which takes into account all the technical, economic and environmental constraints which combine naturally with other tools for aiding multi-criteria decision making.

3.4. Oceanographic (littoral) mapping Two examples developed by the Institut fran9ais de recherche pour l'exploitation de l a m e r (IFREMER) make it possible to evaluate the remote sensing contribution in mapping operations devoted to littoral development. The first one concerns aquaculture (Grotte and Populus, 1989) and the pre-selection of sites for breeding tropical shrimps: this type of activity has an important economic potential (growth greater than 20% per annum since 1983). A series of applications undertaken by the IFREMER in New Caledonia and Ecuador led to conclusions fairly similar to those in the preceding section: in comparison with normal mapping methods, satellite imagery makes possible: ( 1 ) a very much greater accessibility in regions where access is difficult; (2) a synoptic overview and a detailed thematic analysis (due to the multispectral channels), more effective for environmental and development studies; (3) better adaptation to computer-assisted mapping and to obtaining quantitative results. The results led to a considerable extension of inventoried resources (6200 hectares instead of 1000-5000 as estimated at the beginning), for a cost equivalent to that of normal methods. The second example concerns the petroleum industry and intervention plans for anticipating or fighting hydrocarbon pollution, particularly near oil wells. Here again, difficult-access, poorly-mapped regions are often involved. An IFREMER example concerned Kalimantan (Borneo) which led to the production of a 1:50000 scale sensitivity map, showing the different vegetation categories, their vulnerability taking into account the hydrographic network, etc. Another document, an operational one, showed the logistic details in an overall manner, making it possible to elaborate strategies depending on the different possible scenarios. On the economic level, a comparison was made using a method based on rectified aerial photography (with the necessary aerial survey) (Table 5 ). The ratio of the costs produced here, lie between 3 and 16 depending on the area processed with sPoT imagery (easy extension for low, additional expenditure ) with, however, an analysis discrimination evidently much greater for the documents based on aerial photography. This very large ratio represents above all the impact of the difficulty of access (it was necessary to charter a special aircraft for the aerial photography ). This phenomenon did not arise in the preceding example of road development in northern France.

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TABLE 5 Comparison of costs for producing an analysis of possible pollution problems using SPOT imageny and aerial photography

Process

Zone covered

Map scale

(kin 2 )

Cost

Cost/

(US $)

km 2

(us$) SPOT imagery Aerial photography

40 to 500 40

1:50 000 1:25 000

12 000-30 000 40 000

60-300 1000

4. CONCLUSION

The four sectors mentioned above (basic mapping, geology, road network development, littoral oceanography), as evaluations of the place of remote sensing in geographic information economics, are imperfect due to their partial nature. In addition, the examples mentioned, except perhaps for basic topographic mapping and for geologic information, only correspond to individual cases: it is still too soon to state that they are totally representative. The dispersion of the results (economic gains ranging from 1.1 to 16) confirm the necessity of other evaluations in order to obtain statistics which are better centered. However, certain conclusions appear as definite, because they are situated at the level of the intrinsic qualities of the satellite imagery (recent nature of the data, synoptic character, thematic richness, etc. ). These concern the improvement of the effectiveness of the final product, independent of its cost, which advantages again add to the economic gains realized duning the production of the information. The difficulty is, as always, to give numbers to those "qualitative" advantages. One rejoins here the general problem arising in the first part of this report: how can one evaluate the economic and social utility of geographic information? The reply, as we have seen, is not theoretical. It has to be based rather on studies of precise cases with impacts which are relatively easy to evaluate. However, one can foresee that the conclusion will not be uncertain nor fragmentary: it can only reinforce the awareness that one has of the increasing importance of geographic information and its visible face, cartography.

REFERENCES Auzel, L., Hersan, A., Bernier, P. and Dupont, L., 1988. Les r~seaux structuraux p6riurbains dans le d6veloppement des villes: projet-pilote d'utilisation des images SPOT pour l'~tude

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d'impact de la rocade de Maubeuge. Int. ISTED Colloq. G6nie urbain et d6veloppement, September, Lyon, France. Denis, P. and Baudoin, A., 1988. Applications topographiques de SPOT ~ l'IGN-France". In: Proc. ISPRS Congr. (Kyoto, Japan). " Didier, M., 1990. Utilit6 6conomique et sociale de l'information g6ographique. Editions Economica, Paris. Grotte, A. and Populus, J., 1989. D6veloppement d'applications en cartographie littorale et oc6anographique CNIG Symp. 12 June. Konecny, G., 1987. Review of the latest technology in satellite mapping. World Cartography, United Nations, New York. Vol. 20, pp. 117-123. Spiess, E., 1987. The use of large format camera imagery for updating topographic maps at 1: 100 000. 13th ICA Conf. October, Morelia. United Nations Economic and Social Council, "Status of the World Topographic and Cadastral Mapping" January 1987 (prepared by Dr. A.J. Brandenberger and Dr. S.K. Ghosh, Laval University, Quebec, Canada).