20 research outputs found
Radar Remote Sensing For Vegetation With Special Reference To Nipah Delineation On Sir-A Image
ABSTRACT
Active microwave is a promising tool for monitoring vegetation and agricultural crops: the biomass, the stage of growth and deviations from regular plant development due to stress and ivestation may be inferred from radar data. In order to do so, two main steps must be considered: the changes of the measured radar signals must be correlated to the backscattering coefficients of the targets, the latter of which must be defined towards the biomass and structure of the vegetation. The definition of such relationship is,not an easy task due to the large number of physical parameters which characterize the target (type of crop and soil, humidity, structure, slope, etc.) and the sensor (wavelength, polarization, shooting angle). Moreover, these parameters are interrelated. Two basic models and some experiments, especially with reference to a successful but unexplained attempt of Nipah delineation with SIR-A imagery is presented after three main levels of vegetation observation are defined and the main physical parameters for the backscattering process are reviewed Although the few experiments conducted to date show that imaging radar has the potential to provide useful information with regard to vegetation no concrete information exists with regard to optimum angle of incidence, frequency or polarization configuration
Kata Kunci: radar remote - vegetatio
Geography with the environmental satellites
Coarse spatial resolution, high temporal frequency data from the earth polar orbiting (NOAA. HACMM, Nimbus, etc.) satellites and from the geostationary (GOES. Meteosat, and GMS) satellites are presented to demonstrate their utility for monitoring terrestrial and atmospheric processes. The main characteristics of these ,satellites and of the instruments on board are reviewed. In order to be useful for environmental assessments. the remotely sensed data must be processed (atmospheric and geometric corrections, etc.). The NOAA Center provides a wide range of already processed data. such as meteorological. oceanic, hydrologic and vegetation productso rough description of these preprocessed data is given in this article. Finally, some examples of applicotions in Southeast Asia and especially in Indonesia, are described, i.e.: agroecosystem, drought and oceanic monitoring. The paper concludes that coarse resolution, high temporal frequency ,satellite data are very valuable for environmental studies. the emphasis being laid on the improve. ment of the crop and drought assessment programmes
DART: A 3D Model for Remote Sensing Images and Radiative Budget of Earth Surfaces
Modeling the radiative behavior and the energy budget of land surfaces is relevant for many scientific domains such as the study of vegetation functioning with remotely acquired information. DART model (Discrete Anisotropic Radiative Transfer) is developed since 1992. It is one of the most complete 3D models in this domain. It simulates radiative transfer (R.T.) in the optical domain: 3D radiative budget and remote sensing images (i.e., radiance, reflectance, brightness temperature) of vegetation and urban Earth surfaces, for any atmosphere, wavelength, sun/view direction, altitude and spatial resolution. It uses an innovative multispectral approach (flux tracing, exact kernel, discrete ordinate techniques) over the whole optical domain. Here, its potential is illustrated with the case of urban and tropical forest canopies. Moreover, three recent improvements in terms of functionality and operability are presented: account of Earth/Atmosphere curvature for oblique remote sensing measurements, importation of 3D objects simulated as the juxtaposition of triangles with the possibility to transform them into 3D turbid objects, and R.T. simulation in landscapes that have a continuous topography and landscapes that are non repetitive. Finally, preliminary results concerning two application domains are presented. 1) 2D distribution of the reflectance, brightness temperature and radiance measured by a geostationary satellite over a whole continent. 2) 3D radiative budget of natural and urban surfaces with a DART energy budget (EB) component that is being developed. This new model, called DARTEB, is intended to simulate the energy budget of land surfaces
Seasonal and interannual variations of the sea surface temperatures (SST) in the Banda and Arafura sea area
A Procedure For Deriving Geo-Referenced Location For Digital Images
ABSTRACT
Two systems of bilinear interpolation were studied in deriving a procedure for transforming geo-referenced grid locations to locations on maps defined by digital image column and line coordinates. Map data were from 1 : 50.000 Universal Transverse Mercator topographic charts. and digital data were from SPOT satellite dataprocessed to Level lb (CHES. 1979). corrected for Earth rotation and curvature and off-nadir viewing but without local control. Two independent data sets gave similar results: models with two independent variables gave prediccted errors of less than the dimensions of one pixel of the digital data. Models with one independent variable were inadequate for satisfactory transformations. Procedures for collecting and analyzing control data are presented. and trial models are shown and discussed.
Kata Kunci.: deriving geo referenced - digital image
Geography with the environmental satellites
Coarse spatial resolution, high temporal frequency data from the earth polar orbiting (NOAA. HACMM, Nimbus, etc.) satellites and from the geostationary (GOES. Meteosat, and GMS) satellites are presented to demonstrate their utility for monitoring terrestrial and atmospheric processes. The main characteristics of these ,satellites and of the instruments on board are reviewed. In order to be useful for environmental assessments. the remotely sensed data must be processed (atmospheric and geometric corrections, etc.). The NOAA Center provides a wide range of already processed data. such as meteorological. oceanic, hydrologic and vegetation products; o rough description of these preprocessed data is given in this article. Finally, some examples of applicotions in Southeast Asia and especially in Indonesia, are described, i.e.: agroecosystem, drought and oceanic monitoring. The paper concludes that coarse resolution, high temporal frequency ,satellite data are very valuable for environmental studies. the emphasis being laid on the improve. ment of the crop and drought assessment programmes
Monthly Probabilities For Acquiring Remote Sensed Data Of Indonesia With Cloud Cover Less Than 10 , 20 And 30 Percent
ABSTRACT
The Indonesian spatiotemporal cloud cover distribution was quantified with the aid of GMS, Landsat and SPOT data. Iterative interactive factorial analyses grouped pixels with similar profiles into 18 classes for all land areas. For each class, statistics of Landsat and SPOT images, grouped by class, were used to verify, calibrate and improve class profiles. This led to quantified temporal profiles of probability of acquiring remotely sensed data with 10 , 20 and 30 percent cloud cover, for any Indonesian land area
Kata Kunci.: montrhly probabilities - data - image
Remote sensing with spot : an assess ment of spot capability in Indonesia/ Etchegorry
xi, 153 hal. : ill. ; 30 cm
Remote sensing with spot : an assess ment of spot capability in Indonesia/ Etchegorry
xi, 153 hal. : ill. ; 30 cm