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The present article analyses the accuracy of application of higher-order nonlinear interaction models on hyperspectral data to identify mangrove mixtures present in the Sunderbans Delta - a World Heritage Site in West Bengal, India. It is observed that intra-species interaction between similar mangrove species (interaction between the same type of end-members) in a homogeneous mangrove stand is more accurately modelled by the linear-quadratic model and hence results in more accurate fractional abundance estimations after unmixing when compared with linear-unmixing models. Specifically, we observe that quadratic models provide more accurate estimates than linear and bilinear models for the study area (Henry Island of Sunderbans), which is mostly dominated by pure and mixed mangrove species of Avicennia marina, Excoecaria agallocha, Avicennia alba, Phoenix paludosa, Avicennia officinalis, Ceriops decandra, Bruguiera cylindrica and Aegialitis. In this study, the quadratic nonlinear model successfully characterizes the interaction of endmember mixtures comprising E. agallocha, A. officinalis, B. cylindrica and A. alba in the study area. [ABSTRACT FROM AUTHOR]

Here we discuss hyperspectral imaging techniques and present an overview of a number of systems that have been developed by various space agencies. We also present the evolution of these systems and the progress made by the Indian space programme in this field. [ABSTRACT FROM AUTHOR]

Oceansat-2 mission is envisaged to provide continuity of services for the operational users of Ocean Colour Monitor (OCM) data as well as enhance the application potential in other areas. It was successfully launched by PSLV-C14 flight on 23 September 2009 from Shriharikota launch pad. It carried three payload instruments, viz. OCM 2, a Ku-band scatterometer (OSCAT) and a Radio Occultation Sounder for Atmosphere (ROSA) which has been developed by the Italian Space Agency. A controlled calibration and validation site is envisaged in southeast Arabian Sea to monitor the OCM 2 sensor stability owing to its post-launch performance and ageing-related problems in orbit. This site measures hyper-spectral optical radiances (both in air and underwater), meteorological parameters and CIMEL 318 sun-photometer for sun and sky radiation in automated mode. All these datasets are received from the site via satellite communication. These measurements are analysed along with top-of-the-atmosphere (TOA) radiance measured by OCM 2 sensor. The OCM 2 sensor performance is monitored against the radiance computed at TOA through a forward radiative transfer model for the period spanning from 23 September 2009 to 24 April 2010. [ABSTRACT FROM AUTHOR]