Space research in Western Europe began in the form of independent national space programmes confined in the first instance to the use of sounding rockets. These early steps were soon supplemented by bilateral collaborative projects with the USA and USSR whose agencies provided the satellite launch vehicles that Europe lacked at that time.In 1962 as a result of an agreement between ten member states the European Space Research Organisation (ESRO) was established for the purpose of carrying out a programme of space science. ESRO was succeeded in 1974 by the European Space Agency (ESA) with a much broader range of activities covering both scientific research and the application of space technology together with the development of launch vehicles.At the present time the totality of space activities of the ESA member states is made up of national programmes and collaborative projects with other nations and agencies together with participation in the agreed ESA programme. Because of its essentially non-military character, its relatively modest level of funding and its multinational nature the European experience with ESA may provide some useful guidance in the development of space science and technology elsewhere in the world. 相似文献
The Yangjiatan tungsten district at latitude 27°28′ N. and longitude 111°54′E. is located about 140 km southwest of the city of Changsha and 35 km northeast of the town of Shaoyang, southeast Hunan Province, People's Republic of China. The deposits, consisting largely of scheelite in veins (Wang, 1975), are contained in highly folded and faulted sedimentary rocks of Paleozoic, Mesozoic, and Cenozoic age intruded by granitic plutons that are circular in plan view. The major faults and folds trend in a northeasterly direction; whereas, the plutons are clustered in a more easterly trending band across the Landsat image.Landsat image E-2338-02202, acquired December 26, 1975, is number 470 in the “Landsat Image Atlas of the People's Republic of China” printed by the Publishing House of Geology in 1979. A computer-compatible tape of the image was analyzed and used as a demonstration project under a United Nations technical assistance program. Supervised classification of soils, rocks, and vegetation; band ratioing to detect limonite alteration; and edge enhancement were all conducted to demonstrate the flexibility and capability of interactive computer systems. Field evaluation of the results of this work will be conducted by colleagues of the Remote Sensing Center for Geology, Ministry of Geology, in China. 相似文献
The Shuttle Multispectral Infrared Radiometer (SMIRR) is a spectroradiometer covering the region from 0.5 to 2.5 μm in 10 channels that acquired data from spots 100 m in diameter along the subspacecraft ground track. It was flown aboard the second flight of the space shuttle Columbia, November 12–14, 1981. Data collected during orbit 16 over southern Egypt show that carbonate rocks, kaolinite, and possibly montmorillonite can be identified by their SMIRR spectral signatures and limited knowledge of the lithologic units present. Detailed analysis of SMIRR data for this area indicates that calcite, kaolinite, and montmorillonite rocks give rise to absorption features that result in characteristic 10 channel spectra. 相似文献
Research of the effect of space environment on an ecosystem consisting of plants and animals is essential when they are to be positively used in space. Although there have been experiments on various organisms under space environment in the past, they mainly studied the effect of space environment on an individual organism or a single species. Microcosm is drawing attention as an experimental material of an ecosystem consisting of multiple species. The object in this research is to understand the nature of this network system called ecosystem. Thus, a mixed microorganism culturing system consisting of three types of microorganisms which form a minimum food chain system as a closed ecosystem (chlorella as the producer, bacteria as the decomposer, and rotifer as the consumer) was taken for the subject, on which to research the universal characteristics of ecosystems. From the results of experiments under the terrestrial environment, formation of colonies, which is an ecological structure, has been observed at its mature stage. The organisms form an optimal substance circulation system. Therefore, formation of colonies in simulation models is important. Many attempts have been made to create ecosystem models. For example, the Lotka-Volterra model forms a simultaneous equation with the differential equation expressing predator and prey relationship and many numerical calculations have been conducted on various ecosystems based on expanded L-V models. Conventionally, these top-down methods have been used. However, since this method only describes the average concentration of organisms that are distributed uniformly throughout the system and cannot express the spatial structure of the system, it was difficult to express ecosystem structures like colonies and density distributions. In actual ecosystems, there is heterogeneity in the number of individuals and in substance density, and this is thought to have great significance in ecosystems. Consequently, an individual-based model was used that applies rules to predator-prey relationship, suppression, production, self suppression, etc., of each species. It enabled the emergence of the overall system only by its local rules, and it was possible to reproduce colony generation. In addition, the transition and the ratio of populations for each species match well with experimental results. 相似文献
Since Autumn of 1978, the National Meteorological Center of the United States National Weather Service has been archiving in a single, unique data set, global, daily synoptic analyses and computer gridded fields of geopotential height and temperature at 18 pressure levels from 1000 to 0.4 mb. The paper discusses the fields, with special emphasis on data and analysis procedures used for the stratospheric fields, along with estimates of uncertainties. Results are presented for the mean zonal wind and temperature patterns for each January of the four PMP-1 winters 1978/79 to 1981/82. The Preparatory MAP (Middle Atmosphere Program) Project for coordinated study of the behavior of the middle atmosphere is called PMP-1. 相似文献
A new static-launch method that we have developed as an improvement of our former method is described. The key procedure is to extend a whole balloon vertically upon the launcher before release, with squeezing the top bubble of the balloon by a soft collar. The new method improved the capability for heavier payload significantly. In 1981, 15 balloons, ranging from 5,000 m3 to 50,000 m3 in volume with a total lift from 150 kg to 650 kg, were launched by this new method successfully. 相似文献
The inventory of large often non-homogeneous tracts of land by resource agencies has led to the development of estimation methods and sampling strategies that produce estimates of the aereal extent of various features from ‘limited’ observations of the universe of interest. Landsat data has furnished a tool that allows for potential improvement in estimates of resource parameters over extensive areas. This paper examines the methodology and results of a procedure which uses an economical sampling procedure allied with the large area covering qualities of the satellite imaging system to make improved estimates of irrigated land in a more timely, efficient and ‘accurate’ manner. 相似文献
The paper gives a broad perspective of the progress made during the last 10 years in solving the Navier–Stokes equations and traces how this simulation technique went from being a specialized research topic to a practical engineering tool that design engineers use on a routine basis.
The scope is limited to Navier–Stokes solvers applied to industrial design of airframes with attention focused particularly on developments in Europe. An overview of the different Navier–Stokes codes used in Europe is given, and on-going developments are outlined.
The current state of progress is illustrated by computed steady and unsteady solutions to industrial problems, ranging from airfoil characteristics, flow around an isolated wing, to full aircraft configurations.
A discussion on the future industrial design environment is given, and developments in Europe towards a more integrated design approach with underlying concepts like ‘concurrent engineering (CE)’ and the ‘virtual product (VP)’ are summarized. The paper concludes with a discussion on future challenging applications. 相似文献