Crop parameters estimation by fuzzy inference system using X-band scatterometer data Abhishek Pandey a,⇑ , R. Prasad a , V.P. Singh b , S.K. Jha c , K.K. Shukla d a Department of Applied Physics, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005, U.P., India b Department of Biological and Agricultural Engineering, Texas A & M University, USA c Department of Physics, Faculty of Science (Banaras Hindu University), Varanasi 221005, U.P., India d Department of Computer Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005, U.P., India Received 16 February 2011; received in revised form 15 September 2012; accepted 23 October 2012 Available online 2 November 2012 Abstract Learning fuzzy rule based systems with microwave remote sensing can lead to very useful applications in solving several problems in the field of agriculture. Fuzzy logic provides a simple way to arrive at a definite conclusion based upon imprecise, ambiguous, vague, noisy or missing input information. In the present paper, a subtractive based fuzzy inference system is introduced to estimate the potato crop parameters like biomass, leaf area index, plant height and soil moisture. Scattering coefficient for HH- and VV-polarizations were used as an input in the Fuzzy network. The plant height, biomass, and leaf area index of potato crop and soil moisture measured at its various growth stages were used as the target variables during the training and validation of the network. The estimated values of crop/ soil parameters by this methodology are much closer to the experimental values. The present work confirms the estimation abilities of fuzzy subtractive clustering in potato crop parameters estimation. This technique may be useful for the other crops cultivated over regio- nal or continental level. Ó 2012 COSPAR. Published by Elsevier Ltd. All rights reserved. Keywords: Scattering coefficient; Plant biomass; Soil moisture; Neural networks; Fuzzy subtractive cluster 1. Introduction Agriculture has to meet the needs of current and future generations while continuing to preserve the natural resources through sustainable development. The last Food Agricultural Organization summit in Rome warned that more than 1 billion people are chronically undernourished worldwide (Blumberg, 2007) and that reversing this worri- some hunger trend could require more intensive farming practices (Lin et al., 1994). The problem of starvation is reduced considerably due to potato crop. Potato is the world’s fourth important larg- est food crop after rice, wheat and maize. It is a starchy, tuberous crop from the perennial Solanum tuberosum of the Solanaceae family. It has special value as a food in the country where the nutrition value of the population has to be maintained under inhospitable conditions. The nutritional value of potato per 100 g is carbohydrates 19 g, starch 15 g, protein 2 g, water and other minerals 64 g. Thus for socioeconomic aspects, effort should be made for improvement and spreading the cultivation of this important crop. There is a need for an effective potato mon- itoring program to provide information on potato growing areas and growth conditions. For an effective monitoring of the crop/vegetation, it is necessary to understand the inter- action between microwave radiation, soil and crop/vegeta- tion parameters. Microwave scattering depends upon various factors like surface roughness, target geometry, its dielectric and the incident wave properties. In the micro- wave region, the dielectric properties of soil considerably depend upon water content in the soil. The scattering and 0273-1177/$36.00 Ó 2012 COSPAR. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.asr.2012.10.018 ⇑ Corresponding author. E-mail address: abhiksp@gmail.com (A. Pandey). www.elsevier.com/locate/asr Available online at www.sciencedirect.com Advances in Space Research 51 (2013) 905–911