Technical Note Simulation of MEIS-II data on 5S code to quantify algal concentration in an intertidal area

An atmospheric correction algorithm due to Deschamps et al. (1981) has been applied to MEIS-II data. Some atmospheric conditions such as continental and maritime aerosol models have been used in this work. Simulation on 5S code was made with Thematic Mapper Band 4 and Spot band 3. All these pieces of the puzzle permitted the qualification of algal concentration in an intertidal area, which was the aim of this work. Continental or maritime aerosol models gave a similar result due probably to the specific area, located between land and nearshore. Apparent radiance is smaller than corrected radiance because absorption process takes place in this part of the spectrum (0.8 to 0.9μm). When apparent radiance is higher than 30 Wm^?2 sr^?1 μm^?1 algal concentration is overestimated by up to 60 per cent.     

ON FUZZY INTERPOLATION*

Abstract

This note intends to discuss several connections between interpolative reasoning and fuzzy sets and the role played by the extension principle in this connection. It is first recalled how gradual rules can encode linear or non-linear interpolation between precisely known points and can exactly reconstruct any single-input monotonic real function when the membership functions of the fuzzy sets involved in the rules are suitably chosen. Then linear interpolation between fuzzy points is investigated. The interest of gradual rules as opposed to other approximation schemes is singled out.     

Les systèmes légers de télédétection aéroportée pour les sciences de la Terre

Satellite remote sensing, a powerful monitoring tool, often lacks the high spatial resolution and operational flexibility needed for research in Earth Sciences. In order to highlight the concept of linking ground data and remote sensing imagery, a review of tremendous recent advances in low-altitude remote sensing, as well as in supporting systems such as light airborne platforms is presented. Airborne digital photography and videography provide near real-time data at the local and regional scales. The integration of portable multi-spectral digital sensors, navigation systems and small slow-flying aircraft creates a modern do-it-yourself data acquisition tool for everyday field work and ground truthing of satellite imagery. This approach closes the existing gap between the advanced spaceborne remote sensing methods and the precise but inefficient ground studies. It is particularly advantageous for geomorphology and Earth Sciences.     

Measurement of the thermoelastic coefficient of metals by strain gauges

The modulus of elasticity E of metals and alloys varies, usually, when the ambient temperature θ changes, which is a drawback in most metro logic applications. A thermoelastic coefficient TCE equal to (ΔE/Δθ)/E can be defined. This article shows how this quantity can be measured, dynamometrically and statically, with safety and precision, on a metallic specimen, made of the material under study, on which strain gauges with a known thermal coefficient TCK are bonded.
Experiments carried out at the ONERA Modane-Avrieux Centre during the manufacture of more than one hundred dynamometers, made of several kinds of metals and gauges, showed that the TCKs, given by the gauge manufacturer, were more stable than the TCEs, which justifies a sufficiently fine measurement of the latter. The TCE values of six different materials, lying between -0.44×10³ and + 0.33×10³, have been determined to within 0.02×10^-3 without particular precautions. An absolute precision better than 0.01×10^-3 may be obtained by this process, which also makes it possible to determine the modulus of elasticity E and the Poisson's ratio v.     

OPAL: A multi-knowledge-based system for industrial job-shop scheduling†

A job-shop scheduling software currently under development is described, based on artificial intelligence programming techniques. The idea is 10 be able to make three kinds of knowledge cooperate in the derivation of a feasible schedule: theoretical knowledge (issued form scheduling theory) which achieves the management of time; empirical knowledge about priority rules and their influence on production objectives: and practical knowledge (provided by shop-floor managers) about technological constraints to be satisfied in a given application. The latter is usually not considered in pure operations research algorithms. The system is actually implemented in COMMON LISP and runs on a Texas Explorer LISP Machine and a SUN workstation. Computational results are reported.     

Artificial Intelligence Software Engineering in Building Engineering

This article provides a review of two main research projects carried out at the French Scientific and Technical Center for Building (CSTB) in the area of artificial intelligence applied to building engineering. We first describe the software engineering techniques used to develop the computer environments. Then we present the architecture of an advanced multiservice computer system offering capabilities comprising retrieval facilities, hypertext editing of documents (e.g., unified codes of practice, regulations), object-oriented database management, and multifunctional expert systems. Finally we discuss a major multiactor computeraided design project aiming to provide a framework able to combine the sundry contributions of the various actors involved in the building design process. The expected results of such projects are a panel of complementary capabilities either aiming at satisfying multiservice requirements for an isolated designer or at providing a single but cooperative and computer-assisted process to different actors. Of course, merging the respective capabilities of these tools is a very promising perspective.     

Review of: “ Télédétection spatiale: Université d' été européenne Toulouse 1990”. By MICHEL VAUZELLE (Cépadues-Éditions. Toulouse. 1992) [Pp. 309.] Price FF300.

In this paper, a simple model is proposed for measuring the vegetation cover over soil surfaces from radar signals acquired in semi-arid regions. In such regions, vegetation is characterized by the presence of clumps which partially cover the soil surface. The proposed model describes the relationship between the percentage of covered surface and the measured radar signal. Model simulations over Tunisian test areas, where ground parameters are controlled, are performed and compared with actual ERS2 radar measurements. A very good agreement is found. The model is then used to derive a map of the vegetation cover density for the whole studied site (in Tunisia). The approach used here is based upon supervised classification with classes defined by inverting the model and taking into account ERS calibration error. Each of the four classes thus defined exhibits a good classification rate, greater than 85%. Finally, two important applications for natural resources management are presented: vegetation monitoring and soil moisture monitoring.