Microwave remote sensing studies for ground water applications
Student name: Ms Dhanya Nair
Guide: Mr V.S.P.Sinha
Year of completion: 2011
Host Organisation: Regional Remote Sensing Center
Supervisor (Host Organisation): Dr G. Sreenivasan
Abstract: Active microwave imagery is obtained using instruments and principles that are different
from those used when acquiring data in the visible, near-infrared, mid-infrared, and thermal
infrared portions of electromagnetic spectrum using passive remote sensing techniques.
Microwaves are long wavelength radiations and the range of electromagnetic radiations
used to create radar images extends from wavelengths of less than 1 cm to those of more
than several meters.
Geological information from optical sensors are hindered by cloud cover, identification of
features restricted by illumination conditions, and the delineation of geological structures
dependent on the angle and elevation of the sun. Radar remote sensing has proven to be an
effective tool for the extraction of geological information and parameters such as the
landforms, litho units, the structural details, the nature of weathering, the identification of
recharge & discharge zones, etc., required for estimation of groundwater resources of an
area and its management, unhindered by external illumination and weather conditions.
The main objective of this study is to retrieve the hydrological parameters for ground water
resource management studies using microwave SAR remote sensing. The remote sensing
dataset used for this study are those of RADARSAT-2, LISS III, LISS IV and CARTOSAT-1.
The methodology includes processing of the images which includes removal of speckle,
rectification of errors that include layover and foreshortening and interpretation of features
under shadows. Various digital enhancements are attempted on the SAR data products to
enhance the features of interest. Extraction of geological structures and landforms is carried
out using multi-incidence angle – multi polarization SAR images. The information
interpreted from the SAR satellite data is further integrated in GIS for suggesting
groundwater management strategies. The utility of microwave remote sensing SAR data for
the retrieval of hydrological parameters for groundwater management planning, specifically
identifying ground water prospect zones is demonstrated by the study.
Key Words: Synthetic Aperture Radar (SAR), Microwave remote sensing, Speckle,
Polarization, Groundwater management, Ground Water Prospects.
