Effect of acquisition date and TM spectral bands on wheat,mustard and gram classification accuracies

Single date classification accuracies of wheat, mustard and gram were investigated using TM data of five acquisition dates (January 24, February 9, 16,25 and March 12, 1988) and four band-combinations (TM 234 TM 345, TM 1234 and TM 2345) over an irrigated, optimum fertility site in Hisar (Haryana). Accuracies for wheat and gram were lowest on January 24 for all band-combinations and improved with later acquisitions. An interaction between acquisition date and band combination was apparent as accuracies with most optimal combinations remained high over the period from February 9 to March 12 ,while those with sub optimal combinations fluctuated widely from one date to another. The band-combinations which included middle-infrared (TM 2345 and TM 345) showed highest accuracies irrespective of crop and acquisition date while band combination of TM 234 consistently had lowest accuracies.