Analysis of passive microwave data for large area environmental monitoring.

摘要

Traditionally, "large area" monitoring from satellites has been accomplished using the Advanced Very High Resolution Radiometer (AVHRR), however, the use of this dataset can be significantly affected by the presence of cloud cover. The Special Sensor Microwave Imager (SSM/I) records microwave emissions from the Earth surface. Microwave emissions are independent of cloud cover and therefore provide a useful dataset in areas of significant cloud cover.;The objectives of this work were to evaluate the synergism between the AVHRR and SSM/I sensors, establish a method of scaling between the two datasets and interpret the microwave emissions for the purpose of soil moisture monitoring.;Scaling between the two datasets was accomplished by adding together the locational accuracies and pixel resolution of both datasets. Microwave polarization differences were found to be inversely related with ground temperature. Furthermore, use of polarization differences facilitated observation of the temporal evolution of microwave emissions over three ecoregions.;SSM/I data recorded at 19 GHz was shown to be linearly related to surface moisture even in the presence of vegetation.