ISSN:0143-1161    

DOI:10.1080/01431169308953954

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The water quality parameters chlorophyll-a, total phosphorus, Secchi disk depth, suspended solids, salinity and temperature in the Norfolk Broads have been studied using Landsat TM data. An empirical approach of relating TM data with ground referenced data for these parameters through regression analysis was employed. Significant relationships were established between them. These models were used to predict and map these parameters in 27 or the Norfolk Broads. All the predicted values are consistent with the available general knowledge about these Broads

ISSN:0143-1161    

DOI:10.1080/01431169308953955

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Spaceborne remote sensing of inland water quality is based on the assumption that the relationship between the reflectance and the concentration of relevant water quality constituents is knowna priori.Simultaneous measurements of the upwelling and downwelling irradiances, along with phytoplankton chlorophyll-a, suspended matter and dissolved organic matter concentration at over 20 water bodies throughout former USSR, Hungary, Germany and Bulgaria, are reported in this article. The measurements cover different trophic states of water bodies, from oligotrophic to hypertrophic, and different climatic conditions. The range of chlorophyll-a is 0·1 to 350 mgm-3, suspended matter is 0·1 to 66mg1-1, and dissolved organic matter absorption at the wavelength 380nm is 0·1 to 12m-1.

ISSN:0143-1161    

DOI:10.1080/01431169308953956

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Remotely-sensed data in the form of satellite images and aerial photographs were used in conjunction with ancillary data to study flood related features of River Rapti in the state of Uttar Pradesh, India. The morphological characteristics and sedimentation patterns were used to reconstruct the flood history of the region. The flood history was utilised to forecast dynamics of river channel migration. This information will lead to timely selection of appropriate measures to mitigate flood related damages

ISSN:0143-1161    

DOI:10.1080/01431169308953957

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The remote detection of flooding in the Arctic ice pack has been difficult to accomplish using conventional techniques. We have examined a case of Artie flooding (8 June 1989) with NOAA and DMSP visible and infrared measurements supplemented by DMSP microwave imager (SSM/I) data. Analysis of visible and infrared data for a sunglint region was used to show the distribution of flooding at 72° N, 135° W. A simple model was developed for the radiative transfer at microwave wavelengths through a bring layer over ice. The predictions of the model were found to be consistent with the spatial behaviour of the SSM/I measurements. This case study demonstrates the usefulness of using combine visible, infrared, and microwave measurements to differentiate among flooded, broken ice, and open water regions, even in the presence of cloud cover or surface fog

ISSN:0143-1161    

DOI:10.1080/01431169308953958

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The water surface temperature of Lake Okeechobee under clear sky conditions was investigated in this study through the use of Automatic Picture Transmission (APT) thermal infrared data from the National Oceanic and Atmospheric Administration (NOAA) satellite Advanced Very High Resolution Radiometers (AVHRR). Cloud-free data were acquired during the months of May and December 1989. An image processing approach and regression model were used to convert the grey-level digital numbers of the APT imagery into temperature values. A third-order polynomial equation was successfully used to convert the digital numbers into temperature values with a high coefficient of determination (r2=0·98). The satellite-derived temperatures for Lake Okeechobee were correlated with ground-truth temperature measurements (r2= 0·74). The results of this study indicate that APT data are capable of being converted into lake surface temperatures with acceptable accuracy. Results of paired Mest and variogram analyses indicate that the temperature uniformity of the lake varied with the season, space, and time of day

ISSN:0143-1161    

DOI:10.1080/01431169308953959

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A thermal infrared radiometer indicates a lower sea surface temperature at a large observation angle than the directly measured one. In order to explain this decrease in the apparent temperature, the intensity of the radiation reaching the radiometer is formulated as a function of observation angles of the radiometer. In the equation, we assume that a reflection loss occurs at the sea surface for the radiation from below the surface. The temperature predicted from this formula at the large observation angles fits well to the observed one, indicating that temperatures observed at large observation angles can be corrected

ISSN:0143-1161    

DOI:10.1080/01431169308953960

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Forecasts from an operational system for predicting global diurnal sea surface temperature (SST) variability are compared against multichannel sea surface temperatures calculated from advanced very high resolution radiometer data from the NOAA-9 satellite. The forecast system consists of an upper-ocean model driven by heat fluxes and wind stresses from an operational global weather prediction model. Visual pattern correlations between observed and forecast diurnal changes in SST are generally favourable, indicating that the forecast system is useful. Some systematic deficiencies are also noted: the forecasts do not reproduce the surprisingly sharp boundaries of diurnal warming regions and underpredict the amplitude of the extreme warming events

ISSN:0143-1161    

DOI:10.1080/01431169308953961

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

In this study Principal Components have been calculated using covariance and correlation matrices for Tour data sets: Monthly NOAA-NDVI maximum-value composites, NOAA-LAC data, Landsat-TM data, and SPOT multi-spectral data. An analysis of the results shows consistent improvements in the signal to noise ratio (SNR) using the correlation matrix in comparison to the covariance matrix in the principal components analysis for all the data sets

ISSN:0143-1161    

DOI:10.1080/01431169308953962

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Suitable methods of multivariate statistical analysis have already been shown to be useful to overcome the topographic effect which arises when employing remotely-sensed data in rugged terrain. In the present work the application of these techniques to Gaussiam maximum likelihood classifications is examined. As the maximum likelihood classifier takes into account the internal relations in the multivariate data set, it is generally insensitive to the topographic effect provided that the training points are uniformly distributed with respect to variations in solar illumination angle. On the other hand, the conventional classifier does not perform well if such an assumption is not valid, because the spectral distribution of the training data becomes far from normal and not representative of the original situation. In this case a modification of the classifier which eliminates the information related to the first principal component of the data set of each class can be efficient. The difference in discrimination accuracy between the classical and modified classifications is appreciable when they are applied to extreme situations; an example shows that this difference, evaluated by means of the Kappa coefficient of agreement, may be high and statistically significant

ISSN:0143-1161    

DOI:10.1080/01431169308953963

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor