Showing papers in "Geocarto International in 1990"
TL;DR: A conceptual model of geographic change that treats only changed data over time, then extends the conceptual model to common geographic data types, and introduces a taxonomy of multidimensional access methods for solving the problem of responding to ad hoc queries to a spatiotemporal database.
Abstract: A reasonable goal for geographic information systems is that they be capable of tracing changes in an area by storing historic and anticipated geographic data. This work provides a conceptual, logical, and physical basis for developing such a capability. It introduces a conceptual model of geographic change that treats only changed data over time, then extends the conceptual model to common geographic data types. The literature of time in information processing is reviewed at length and ways to apply this research to geographic needs are suggested. The discussion extends to such implementation issues as clustering, quality control, and volume control.
The later chapters focus on the problem of responding to ad hoc queries to a spatiotemporal database. The discussion introduces a taxonomy of multidimensional access methods. Four distinct classes are selected from the taxonomy and a representative of each class is chosen to implement on small spatiotemporal datasets. Two of the four methods are found to perform acceptably.
614 citations
TL;DR: In this paper, a volume on radar polarimetry for geoscience applications discusses wave properties and polarization, scattering matrix representation for simple targets, scattering models for point and distributed targets, polarimetric scatterometer systems and measurements.
Abstract: The present volume on radar polarimetry for geoscience applications discusses wave properties and polarization, scattering matrix representation for simple targets, scattering models for point and distributed targets, polarimetric scatterometer systems and measurements, polarimetric radar system design, and polarimetric SAR applications. Attention is given to plane waves in a lossless homogeneous medium-wave polarization, polarization synthesis and response, and coordinate system transformations. Topics addressed include high- and low-frequency scattering, rough-surface scattering models, radiative transfer theory and deficiencies thereof, solutions for the radiative transfer equation, and a radiative transfer model for a forest canopy. Also discussed are network analyzer-based polarimetric scatterometers, calibration of polarimetric scatterometers, synthesized polarization response of distributed targets, and measurement of the propagation parameters of a forest canopy.
613 citations
TL;DR: Mooney and Hobbs as mentioned in this paper proposed the International Geosphere Biosphere Program (IGBP) to describe and understand the changes occurring on the surface of the earth and in the earth's atmosphere.
Abstract: Harold A. Mooney and Richard J. Hobbs At present there is enormous concern about the changes that are occurring on the surface of the earth and in the earth's atmosphere, primarily as a result of human activities. These changes, particularly in the atmosphere, have the potential for altering the earth's habitability. International pro grams unprecedented in scope, including the International Geosphere Biosphere Program, have been initiated to describe and understand these changes. The global change program will call for coordinated measure ments on a global scale of those interactive physical and biological pro cesses that regulate the earth system. The program will rely heavily on the emerging technology of remote sensing from airborne vehicles, particularly satellites. Satellites offer the potential of continuously viewing large seg ments of the earth's surface, thus documenting the changes that are occur ring. The task, however, is not only to document global change, which will be an enormous job, but also to understand the significance of these changes to the biosphere. Effects on the biosphere may cover all spatial scales from global to local. The possibility of measuring biosphere function remot ly and continuously from satellite imagery must be explored quickly and thoroughly in order to meet the challenge of understanding the con sequences of global change. Initial guidelines and approaches are currently being formulated (Dyer and Crossley, 1986; JOI, 1984; NAS, 1986; Rasool, 1987). There are many conceptual and technical issues that must be resolved H. A. Mooney and R. J."
155 citations
TL;DR: In this article, an empirical study was conducted to assess the accuracy of land use change detection using satellite image data acquired ten years apart by sensors with differing spatial resolutions, and it was concluded that image ratioing of multisensor, multidate satellite data produced higher change detection accuracies than did principal components analysis.
Abstract: An empirical study is conducted to assess the accuracy of land use change detection using satellite image data acquired ten years apart by sensors with differing spatial resolutions. The primary goals of the investigation were to (1) compare standard change detection methods applied to image data of varying spatial resolution, (2) assess whether to transform the raster grid of the higher resolution image data to that of the lower resolution raster grid or vice versa in the registration process, (3) determine if Landsat/Thermatic Mapper or SPOT/High Resolution Visible multispectral data provide more accurate detection of land use changes when registered to historical Landsat/MSS data. It is concluded that image ratioing of multisensor, multidate satellite data produced higher change detection accuracies than did principal components analysis, and that it is useful as a land use change enhancement method.
43 citations
TL;DR: In this article, the structural and thematic mapping of shallow coral reefs using SPOT data is described. And the separation of various living coral themes, as measured by differences in areal coral density, has also been achieved.
Abstract: This paper describes the application of high‐resolution SPOT data for the structural and thematic mapping of shallow coral reefs. Results are presented as structural and thematic maps of the main reef environment types. Different substrate themes including soft bottom, coral debris, coral rubble, and living coral have been identified. The separation of various living coral themes, as measured by differences in areal coral density, has also been achieved.
21 citations
TL;DR: In this article, the authors present observations from space of the open water areas within Lake Chad, which demonstrate a decrease of about 90 percent in surface area between 1966 and 1986, and the analysis of these maps throughout the year reveals the functioning of the lake as well as the large variability of the Open Water areas during a year.
Abstract: Observations from space of the open water areas within Lake Chad are presented. They complement and sustain the earlier study of Mohler et al. (1989), which demonstrates a decrease of about 90 percent in surface between 1966 and 1986. Further, Meteosat images were processed to obtain weekly maps of albedo following the scheme of Moussu et al. (1989). The analysis of these maps throughout the year reveals the functioning of the lake as well as the large variability of the open water areas during a year.
16 citations
TL;DR: Hoffman and Conway as discussed by the authors reviewed some of the available psychological research that pertains to remote sensing, focusing on two major problem areas: Research on the knowledge of expert interpreters of remotely-sensed imagery, and research on the use of color in graphic displays.
Abstract: In a previous article (Hoffman & Conway, 1989), we reviewed some of the available psychological research that pertains to remote sensing. We focused on two major problem areas: Research on the knowledge of expert interpreters of remotely‐sensed imagery, and research on the use of color in graphic displays. Here, we pursue one of the broad implications of the research ‐ that the field of remote sensing can benefit by incorporating research methods and ideas from experimental psychology. From the experimental psychology viewpoint, “remote sensing”; is actually a misnomer when used to denote a field or area of scientific inquiry. Remote perceiving, as a total process, depends not only on the technology of remote sensing, but also depends critically on the ability of humans to interpret remote sensing displays. This perspective is contrasted with traditional approaches to remote sensing. The discussion involves some ideas about the theoretical and methodological foundations of remote sensing as a uni...
15 citations
TL;DR: In this article, the inventory branch of the British Columbia Ministry of Forests used satellite remote sensing techniques using Landsat TM data integrated with CAM/GIS technology to streamline the update procedure.
Abstract: The Inventory Branch, B.C. Ministry of Forests has the mandate to annually update the provincial forest inventory database which consists of over 6,600, 1:20,000 scale mapsheets. Updating a database of this size using conventional photointerpretation and manual drafting is time consuming and costly. Digital satellite remote sensing techniques using Landsat TM data integrated with CAM/GIS technology have provided an efficient and cost effective method of streamlining the update procedure. In the future, updating may be further enhanced by incorporating digital change detection methods, classification, raster to vector conversion techniques and digital terrain correction. This paper describes how such technology is currently being used operationally in British Columbia.
14 citations
TL;DR: A consistent methodology for visual interpretation of vegetation categories is presented in this article, where two false-color images from different seasons were interpreted at 1: 250,000 scale, and benefits and disadvantages of this procedure are analyzed, as well as keys for visual identification of land cover categories.
Abstract: Digital processing of Landsat images has been considered the most appropriate interpretation method for vegetation mapping. However, digital processing presents several difficulties: (i) it demands significant inversions, with respect both the images and the equipment; (ii) it presents problems to discriminate heterogeneous categories, and (iii) it requires much more training effort. Visual analysis, on the other hand, is less demanding both in economic investments and training. Therefore, it is a fruitful alternative to digital mapping, especially when it is applied to small and medium scale inventories. A consistent methodology for visual interpretation of vegetation categories is presented in this paper. Benefits and disadvantages of this procedure are analyzed, as well as keys‐for visual identification of land cover categories. A TM Quarter of scene on Central Spain is presented as an example of this method. Two false‐color images from different seasons were interpreted at 1: 250,000 scale. F...
11 citations
TL;DR: In this article, a multispectral and multitemporal analysis of the spectral response of rice has made it possible to determine at which point in the vegetative cycle of rice it is best to make an inventory, together with the usefulness of the normalized difference vegetation index for such an inventory.
Abstract: The multispectral and multitemporal analysis of the spectral response of rice has made it possible to determine at which point in the vegetative cycle of rice it is best to make an inventory, together with the usefulness of the normalized‐difference vegetation index for such an inventory. The results could be usefully included in any classification procedure of the TM image in order to make the inventory in a systematic way. In this case a supervised classification of the image has been made which assumes a Gaussian behaviour for each spectral class. The results obtained are, for the most part, consistent with those obtained by using traditional methods.
9 citations
TL;DR: In this paper, the effects of the Yellowstone National Park wildfires that occurred in 1988 and the techniques employed to combat these fires with the use of remote sensing are discussed. But the authors focus on the effects on ecosystem recovery and development.
Abstract: An overview is presented of the effects of the wildfires that occurred in the Yellowstone National Park during 1988 and the techniques employed to combat these fires with the use of remote sensing. The fire management team utilized King-Air and Merlin aircraft flying night missions with a thermal IR line-scanning system. NASA-Ames Research Center assisted with an ER-2 high altitude aircraft with the ability to down-link active data from the aircraft via a teledetection system. The ER-2 was equipped with a multispectral Thematic Mapper Simulator scanner and the resultant map data and video imagery was provided to the fire command personnel for field evaluation and fire suppression activities. This type of information proved very valuable to the fire control management personnel and to the continuing ecological research goals of NASA-Ames scientists analyzing the effects of burn type and severity on ecosystem recovery and development.
TL;DR: In this paper, the diurnal variation of the bidirectional reflectance factor (BRF) in nadir direction on the footslopes is dominated by the effect of roughness.
Abstract: In an area in southern Tunisia diurnal trends of bare soil surfaces have been investigated. The study area comprises two main parts: the footslopes and the playas. The diurnal variation of the bidirectional reflectance factor (BRF) in nadir direction on the footslopes is dominated by the effect of roughness. Maximum BRF is found with small solar zenith angles due to decrease in shadow related to surface roughness. For Landsat overpass it implies that the normal ground reflectance for a bare surface on the footslopes at identical surface conditions is up to 10% lower in December (solar zenith angle 63 degrees) than in June (28 degrees). Band ratios on the footslopes hardly change with variation of zenith angle. The diurnal variation in the playas is dominated by moisture. Asymmetric daily curves, with the lowest reflectance in the morning have been found. Four phenomena are reported which can be held responsible for this effect. This daily effect of moisture is weather dependent and may obscure lo...
TL;DR: In this article, a regression analysis between final grain yield values of a group of rice fields and the values which correspond to different vegetation indices constructed from Thematic Mapper bands has been made.
Abstract: In this paper, a study has been made of the relationship between rice productivity and rice reflectance with a view to examining the possibility of predicting grain production. To this end a regression analysis between final grain yield values of a group of ricefields and the values which correspond to different vegetation indices constructed from Thematic Mapper bands has been made. It has been found that the indices constructed from TM4 and TM3 bands of an image belonging to the ripenning phase of rice are, fundamentally, those which show a great correlation coefficient with the final grain production.
TL;DR: In this article, changes in natural vegetation cover comprising the Kalahari rangeland were undertaken using Landsat MSS imagery over a period of above average rainfall (1972-1982) and a periodof drought (1982-1986) to determine whether changes in the range were related primarily to rainfall events or to man-induced effects.
Abstract: Changes in natural vegetation cover comprising the Kalahari rangeland were undertaken using Landsat MSS imagery over a period of above average rainfall (1972–1982) and a period of drought (1982–1986). This and ancillary data were collected to determine whether changes in the range were related primarily to rainfall events or to man‐induced effects. Data from different orbits were made compatible digitally. Dark area subtraction was a problem because deep shadow and water were lacking in the Kalahari landscape. Eleven land‐use/land cover classes were derived for the 1984 base year. Additional signatures had to be obtained for the later drought years because of extreme increases in brightness. Broadly the south‐eastern Kalahari was divided into an interior, relatively uninhabited homogeneous area and a more diverse area containing fossil valleys and pans. Changes in vegetation cover in the interior appeared to be more related to rainfall events than anthropogenic factors. Changes in the fossil vall...
TL;DR: In this article, ancillary information stored on digital files were used in this research to remove (mask) non-agricultural areas from satellite image data, which showed that improvement ranged from 3% to 26% depending on crop type.
Abstract: The Regione del Veneto (Italy) is cooperating with the University of California, Santa Barbara and other researchers in Italy and the U.S.A. to develop a system of econometric crop production modeling. Five crops are to be included in this project: small grains (wheat and barley), corn, sugar beets, soybeans, orchards and vineyards. A critical part of the crop yield modeling process is the identification of crops using multispectral satellite data. This paper explores two strategies to improve crop classification accuracies: (1) use of ancillary data stored in digital format and (2) use of multitemporal data. Ancillary information stored on digital files were used in this research to remove (mask) non‐agricultural areas from satellite image data. Comparison between the classification of masked and unmasked images showed that improvement ranged from 3% to 26% depending on crop type. The multidate classification was performed by compiling an image of transformed spectral bands and three TM‐5 bands....
TL;DR: A review of post-flight cataloging and indexing activities of mission data obtained from Space Shuttle earth observations photography is presented in this paper, where a catalog of Space Shuttle Earth Observations Handheld Photography is published.
Abstract: A review is presented of postflight cataloging and indexing activities of mission data obtained from Space Shuttle earth observations photography. Each Space Shuttle mission acquires 1300-4400 photographs of the earth that are reviewed and interpreted by a team of photointerpreters and cataloging specialists. Every photograph's manual and electronic set of plots is compared for accuracy of its locational coordinates. This cataloging activity is a critical and principal part of postflight activity and ensures that the database is accurate, updated and consequently made meaningful for further utilization in the applications and research communities. A final product in the form of a Catalog of Space Shuttle Earth Observations Handheld Photography is published for users of this database.
TL;DR: In this paper, ground verification maps were produced from field surveys and interpretation of 1.12,000 and 1: 58,000 color-infrared (CIR) aerial photography of nine compartments.
Abstract: Landsat Thematic Mapper (TM) and Multispectral Scanner (MSS) data were digitally analyzed for forest type identification in the Kisatchie Ranger District, Kisatchie National Forest, Louisiana. Ground‐verification maps were produced from field surveys and interpretation of 1.12,000 and 1: 58,000 color‐infrared (CIR) aerial photography of nine compartments. Stand boundary and soils maps were input to a digital Geographic Information System (GIS) with the Landsat and ground‐verification data. ‐ Unsupervised classifications of the Landsat data did not identify the above cover types well. Supervised classifications were tested by stand agreement to the ground verification. The highest four‐class agreement was obtained for the TM classification (76 percent). Three‐class (open, pine, and hardwoods) stand agreements (81 (MSS) and 85 (TM) percent) were not significantly different as tested by analysis of variance (alpha level 0.1).
TL;DR: In this article, several land use and cover maps of Narathiwat province are derived from various single band, three-band color combinations, using unsupervised and supervised classifications of Landsat Thematic Mapper data available at the INRDM Program, Asian Institute of Technology.
Abstract: Several land useAand cover maps of Narathiwat province are derived from various single band, three‐band color combinations, using unsupervised and supervised classifications of Landsat Thematic Mapper data available at the INRDM Program, Asian Institute of Technology. The Landsat Thematic Mapper data used has been radiometrically and geometrically corrected and a final ground resolution of 25×25m was obtained. Although the land useAand cover of the area is complex, the tested accuracy is satisfactory.
TL;DR: An overview of the STS-28 earth observation is provided with attention given to meteorology, oceanographic phenomena, and human activity such as urban environments and related land uses.
Abstract: An overview of the STS-28 earth observation is provided with attention given to meteorology, oceanographic phenomena, and human activity such as urban environments and related land uses. Environmental observations discussed include evidence of a monsoon, vegetation changes such as deforestation, and water pollution and eutrophication of major rivers. Particular attention is paid to atmospheric palls in both the Northern and Southern Hemispheres. Discussion of geological observations focuses on the Mount St. Helens volcano and the little-recognized landform type, the immense illuvial cone. Observation techniques include use of color infrared film and two types of polarization observations.
TL;DR: The earth observations that were conducted during the STS-30 mission in May 1989 are examined in this paper, noting the launch of the Magellan spacecraft and the use of the photographs for various research purposes, including oceanography, meteorology and polarization experiments.
Abstract: The earth observations that were conducted during the STS-30 mission in May, 1989 are examined. An overview of the STS-30 mission is given, noting the launch of the Magellan spacecraft. The major positions of STS-30 photographs are illustrated and the sun elevation angles of the photographs and the types of films used during the mission are listed. Photographs of various regions are described, focusing on North Africa and the Middle East, South and Southeast Asia, Central America, the Caribbean, and the Southern U.S. The use of the photographs for various research purposes is discussed, including oceanography, meteorology, and polarization experiments. Also, consideration is given to the use of video/camcorders for earth observations.
TL;DR: In this article, it is shown that dedicated premission, real-time, and postmission support for planning, acquiring, and interpreting remotely sensed data of specific sites in terms of illumination geometry, atmospheric transmissivity, and preferred viewing is required in order to acquire the best possible earth-viewing photography for each Shuttle mission.
Abstract: It is shown that dedicated premission, real-time, and postmission support for planning, acquiring, and interpreting remotely sensed data of specific sites in terms of illumination geometry, atmospheric transmissivity, and preferred viewing is required in order to acquire the best possible earth-viewing photography for each Shuttle mission. Mission support has resulted in significant advances for the earth observation activities and other experiments carried out by astronauts. Scientific and mission support are described and equipment and capabilities are reviewed. Future advances listed include improvement of existing data bases, expanding access to climatological databases of atmospheric constituents and aerosols, and expanding access to image data such as the DMSP, while Space Station Freedom will require 24-hour operational support.
TL;DR: An overview of photographs, astronaut impressions, and photographic equipment and techniques coincident with the Discovery STS-33 mission of November 23-27, 1989 is presented in this paper.
Abstract: An overview is presented of photographs, astronaut impressions, and photographic equipment and techniques coincident with the Discovery STS-33 mission of November 23-27, 1989. Particularly significant geographical photographs of southern Africa, Madagascar, northern Africa, Southeast Asia islands, Pacific islands, and Australia are shown and reviewed. Meteorological and oceanographic observations are summarized along with film anomalies that occurred during this mission.
TL;DR: The Automated Planning Mission Planning System (AMPS) as discussed by the authors is a computer cartographic system developed by NASA in response to the need to streamline support for an increasing number and frequency of Shuttle missions and to enhance the quality of products produced for mission support.
Abstract: A description is given of the Automated Planning Mission Planning System (AMPS), a computer cartographic system developed by NASA in response to the need to streamline support for an increasing number and frequency of Shuttle missions and to enhance the quality of products produced for mission support. AMPS is menu driven and can plot orbit tracks and revolution times and site boundaries on Mercator projection maps. As an overall site selection process approaches, AMPS reduces the possibility of errors, is time effective, improves SSEOP products, and is adaptable for other related applications.
TL;DR: An overview of the 31st Space Shuttle mission, whose major objective was to deploy the Galileo spacecraft, is presented in this paper, where the most significant STS-34 earth photography for the major geographical regions is discussed.
Abstract: An overview is presented of the 31st Space Shuttle mission, whose major objective was to deploy the Galileo spacecraft Color images are presented of photos taken by the four videocameras in the payload bay, one 16-mm Arriflex in the cabin, a videocamcorder, three 35 mm cameras, two 70 mm cameras, and an IMAX camera In addition, descriptions of visual observations by the mission astronauts are given The most significant STS-34 earth photography for the major geographical regions is discussed Individual highlights of this mission include observation of the apparent recovery of the water level of Lake Nasser to conditions similar to those during the second Space Shuttle mission of 1981; the documentation of the impact of the Yucatan forest blowdown and fires after the passage of Hurricane Gilbert; and the confirmation of the high value of space photography under low and very low sun angle conditions for geomorphological and geological analyses