B. S. Daya Sagar was born on February 24, 1967 in Eluru, Andhra Pradesh, India. Dr. Daya Sagar is a full Professor and First Head of the Systems Science and Informatics Unit (SSIU) at Indian Statistical Institute. He holds a B.Sc. (1987) in Geology from the Andhra University, and a M.Sc. (1991) and Ph.D. (1994) in Geoengineering and Remote Sensing from the Faculty of Engineering of the Andhra University. He held various research positions starting his research career as a Project Fellow (1991-92), CSIR- Senior Research Fellow (1992-94), Research Associate (1995), DST Young Scientist/Principal Investigator (1996-97), and again as Research Associate in 1998. Dr. Sagar spent over two years (1998-2001) as a Grade-A Research Scientist in the Centre for Remote Imaging Sensing and Processing (CRISP) at the National University of Singapore before taking an Associate Professor position in the Faculty of Engineering and Technology at the Multimedia University-Malaysia in 2001. He has moved to the Indian Statistical Institute in 2007, and has been the founding Head overseeing the activities of SSIU. He [Sagar] has been working in the area of applications of mathematical morphology since the early 1990s. Terrestrial surfaces of Earth and Earth-like planets exhibit variations across spatio-temporal scales. Recent advancements in remote sensing technologies that take the advantage of wavelength bands of wide ranging electromagnetic spectra paved a way to properly sense the terrestrial-oceanic-atmospheric fields. Now various different satellites provide optical and microwave remotely sensed data. Optical images are usefully acquired by employing the solar radiation as main energy to sense the terrestrial and/or ocean surfaces. While such optical data have limitations due to cloud cover, microwave sensing mechanisms that are operated via backscatter strength of the radar signal provide data that are useful under all weather conditions. It is recently mentioned that such data that are being acquired with huge expenditure are being under utilized. His works mainly address the (i) feature retrieval from remotely sensed data of both the types, (ii) analysis, (iii) reasoning and modeling phenomena that are retrieved at multiple spatial and temporal scales. To address the these topics, which are intertwined, Sagar’s research works in the past and present involve development of original algorithms and modeling techniques that are mainly based on mathematical morphology, fractal geometry, and chaos theory. In order to develop models, synthetic data sets are considered. The success of the model is further validated through testing the model on realistic data such as remotely sensed data. In several studies he has employed, concepts form mathematical morphology, fractal geometry, and nonlinear studies in computations, modeling, simulation and characterization of phenomena of interest to geoscientists. The phenomena that were addressed in these investigations include small water bodies, channel networks, watersheds, sand dunes, sand stone porous media. He has done very significant work on mathematical morphology applied to terrestrial geomorphology and geospatial computing. He is primarily interested in applications of fractals, multifractals, mathematical morphology and 1-D maps to deal with various aspects of geomorphic and geophysical phenomena (e.g. water bodies, channel networks, sand dunes, symmetrical geological fold). To deal with these studies, he has used nonlinear mathematical morphological concepts to understand the spatio-temporal dynamics in discrete space; and fractals, multifractals and 1-D maps to characterize and quantify the heterogeneities in spatio-temporal dynamics in discrete space. His interests also include the usage of multiscale and multi-temporal digital elevation models derived from various remotely sensed data to extract complex topological information further to characterize these features and to quantify the degree of heterogeneities which are of interest to geomorphologists and geophysicists. He is also involved in applying fractals and non-linear transformations to generate fractal graphics/fractal landscapes, and watershed algorithms for map based hydrological modeling. The applications of the research works, where he is involved, can be foreseen in the fields of simulation and modeling of various surface processes, analysis of remotely sensed satellite digital data and digital elevation models, geocomputation, and spatial analysis. His recent interests include modeling and simulation of lake dynamical behavior in a lattice space. Under his supervision, SIX doctoral degrees and FOUR MENGSc (by research) degrees have been awarded. He has over 55 scientific publications to his credit in renowned international journals, which are indexed in Institute for Scientific Information. His research results have been published in various international journals such as Journal Geophysical Research-Solid Earth, Journal Geophysical Research-Atmospheres, Geophysical Research Letters, Water Resources Research, Nonlinear Processes in Geophysics, IEEE Geoscience and Remote Sensing Letters, IEEE Signal Processing Letters, IEEE Transactions on Power Delivery, Signal Processing, Chaos Solitons & Fractals, Computers & Geoscience, Current Science, Discrete Dynamics in Nature and Society, Fractals, International Journal of Remote Sensing, IEEE Transactions on Pattern Analysis and Machine Intelligence, IEEE Transactions on Image Processing, IEEE Journal on Selected Topics on Applied Earth Observation and Remote Sensing, and Journal Mathematical Geoscience. He has been an invited editor for special issues of Mathematical Geosciences (in memory of the Late Professor SVLN Rao), International Journal of Pattern Recognition and Artificial Intelligence (Quantitative Image Morphology), Chaos Solitons & Fractals (Fractals in Geophysics), and a special section on “Surficial Mapping” for I.E.E.E Geoscience and Remote Sensing Letters (GRSL), International Journal of Remote Sensing (Spatial Information Retrieval, Analysis, Reasoning and Modelling), IEEE Journal on Selected Topics in Signal Processing (Filtering and Segmentation with Mathematical Morphology) which are released in 2001, 2003, 2004, 2005, 2010, and 2012. He is currently serving as an Editor of Discrete Dynamics in Nature and Society: a Multidisciplinary Research and Review Journal, Computers & Geosciences, Frontiers: Environmental Informatics, Image Analysis & Stereology, and served as an Associate Editor of IEEE GRSL (2004-06) and IEEE JSTSP (2011-12). He has reviewed books and scientific articles for University Press (India), IEEE GRSL, Chaos Solitons & Fractals, Computers & Geosciences, International Association for Pattern Recognition, International Journal of Pattern Recognition and Artificial Intelligence, International Journal of Remote Sensing, Journal Mathematical Geology, Discrete Dynamics in Nature and Society, IEEE Transactions on Pattern Analysis and Machine Intelligence, Tribology, IEEE Transactions on Geoscience and Remote Sensing, IEEE Geoscience and Remote Sensing Letters. He has delivered lectures/talks as participant/contestant/invited speaker/guest faculty in Andhra University, A.P. Akademi of Sciences, Indian National Science Academy (INSA), Tata Institute of Fundamental Research, United Nation’s affiliated Centre for Space Science Technology Education-Asia Pacific Region (CSSTE-AP), Centre for Remote Imaging Sensing, Processing, National University of Singapore, Multimedia University, Malaysia, Indian Statistical Institute-Kolkata, University of Hyderabad, and at Bangalore University. He is a recipient of Dr. Balakrishna Memorial Award from Andhra Pradesh Akademi of Sciences in 1995. He is a recipient of prestigious Krishnan Gold Medal-2002 from Indian Geophysical Union. He was a finalist, for INSA young scientist medals in 1996 and 1998, and Swarnajayanthi Fellowship 1999. In 2011, he was selected as Georges Matheron Awardee with Lecturership by International Association for Mathematical Geoscientists (IAMG). He was a short-term visiting fellow at Jawaharlal Nehru Centre for Advanced Scientific Research, Tata Institute of Fundamental Research, and Indira Gandhi Centre for Atomic Research. He was an elected Fellow of Royal Geographical Society (FRGS), Fellow of Indian Geophysical Union, and was a member of New York Academy of Science during 1995-96. He is an elected Senior Member to IEEE (Geoscience and Remote Sensing Society, and Computer Society). He is a technical Program Committee (TPC) member of IGARSS 2006, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016. For more details about him, following webpages may be referred at http://www.isibang.ac.in/~bsdsagar, https://en.wikipedia.org/wiki/B._S._Daya_Sagar. He can be reached via e-mail [email protected]
, [email protected]
Mathematical Morphology, Fractal Geometry, Geographical Information Science, Remote Sensing, Digital Image Processing, Digital Geographics
Areas of Research / Professional Expertise
In terms of research achievement, Professor Sagar has demonstrated the connections between (i) pattern retrieval, (ii) pattern analysis, (iii) simulation and modelling, and (iv) spatial reasoning, and their importance in understanding spatiotemporal behaviours of terrestrial phenomena and processes. For retrieval of topologically unique geomorphologic features from both fluvial and tidal regions, he has developed generalized algorithms. He has shown the evidence of self-organization in several terrestrial phenomena and processes via scaling laws, and has observed their limited utility to distinguish between the geomorphologic basins possessing topologically invariant networks. Based on such an observation, he provided approaches to derive shape-independent but scale-invariant indices for better terrestrial analysis. He has developed a Fractal-Skeletal Channel Network model that can exhibit various empirical features that the random model cannot. Through discrete simulations based on the interplay between numeric and graphic analyses, he has shown various behavioural phases that geomorphologic systems – such as water bodies, folds, dunes, landscapes – traverse. Recently, he developed novel methods for spatial interpolation and spatial reasoning to visualize spatiotemporal behaviour, generating contiguous maps, and identifying strategically significant set(s). His work has stimulated interdisciplinary activity and has yielded insights for quantitative geomorphology and spatiotemporal GISci.