Development of Spectral Indexes in Hyperspectral Imagery for Land Cover Assessment

ABSTRACT

Spectral indexes (SI) are widely used for land cover characterization and also in several physical models for the study of land surface processes. For example, the normalized differenced vegetation index (NDVI) is used in the characterization of soil moisture along with shortwave infrared reflectance. However, for hyperspectral imagery (HSI) comprising many bands within a single spectrum, it is significant to identify the optimal bands for the development of SI. In this paper, we study the potential of band selection in specific bandwidths for the determination of SI. The proposed methodology includes two strategies for development of SI: direct SI determined by the best band within specific spectrums and fused SI determined by fusion of two best bands within specific spectrums. The experiments are conducted using three datasets, two corresponding to snow-covered areas, studied using the normalized differenced snow index (NDSI) and one comprising the agricultural area, studied using NDVI. The developed SI are evaluated through a comparison with the supervised classification maps from the corresponding HSI. A kappa coefficient of 0.693, 0.726 and 0.803 was observed between the results obtained from histogram slicing of SI with respect to the classification maps for the three datasets, respectively.

KEYWORDS:

• Band selection
• Classification
• Hyperspectral
• LULC
• NDVI
• NDSI

Acknowledgements

The authors would like to thank NASA JPL for providing the AVIRIS data of Mammoth Crest, CA and USGS for providing the Hyperion data of Burwa, India. The authors would also like to thank Dr. L. Johnson and Dr. J. A. Gualtieri for providing the AVIRIS Salinas dataset used in our experiments. The authors also thank Dr. Anand Mehta for their valuable inputs in the preparation of this manuscript.

ORCID

Divyesh M. Varade http://orcid.org/0000-0003-0283-8387 Ajay K. Maurya http://orcid.org/0000-0003-0855-3868

Additional information

Funding

This work is supported in part by the Department of Science and Technology, Government of India, under Project number. “DST-CE-2016056”, theme V. “Snow and Glaciers”.

Notes on contributors

Divyesh M. Varade

Divyesh Varade received the M.Sc. degree in Earth Oriented Space Science and Technology (ESPACE) with specialization in remote sensing, from the Technical University of Munich, Munich, Germany in 2011 and engineering degree in electronics and communications engineering from the Rajiv Gandhi Proudyogiki Vishwavidyalaya, Bhopal, India, in 2008. Currently, He has been working towards his Ph.D. degree at the Civil Engineering Department, Indian Institute of Technology, Kanpur, Kanpur, India. He has previously completed his M.Sc. thesis with the Remote Sensing Technology Institute, Photogrammetry and Image Analysis, Institute of Remote Sensing (IMF) at the German Aerospace Center, (DLR), Oberpfaffenhofen, Munich. His research involves mapping, characterization of snow cover using multi-sensor remote sensing data. His expertise involve image processing, pattern recognition, automatic detection and mapping of snow cover, estimation of snow geophysical parameters with optical imagery and active microwave remote sensing and SAR polarimetry.

Ajay K. Maurya

Ajay Kumar Maurya received the M.Tech. degree in GIS & Remote Sensing, from Motilal Nehru National Institute of Technology, Allahabad, Allahabad, India, in 2016 and engineering degree in Computer Science & Engineering from the Bundelkhand Institute of Engineering & Technology, Jhansi, Jhansi, India, in 2012. Currently, He is a Ph.D. student at the department of Civil Engineering Department, Indian Institute of Technology, Kanpur, Kanpur, India. His research involves GPS, image processing, pattern recognition and surveying. Email: [email protected]

Onkar Dikshit

Onkar Dikshit received the B.E. and M.E. degrees in civil engineering from the University of Roorkee, Roorkee, India, in 1985 and 1987, respectively and the Ph.D. degree from the University of Cambridge, Cambridge, U.K., in 1992. Currently, he is a Professor of Civil Engineering with IIT Kanpur, Kanpur, India. His research interest includes image processing, pattern recognition, remote sensing, GPS, GIS, surveying, archaeological, and resource management problems. Email: [email protected]