Comparison of TRMM 3B42 products with surface rainfall over bangladesh

AbstractFor better understanding and monitoring of rainfalls over Bangladesh, where ground-based rain measurement network is not enough, TRMM-PR data is useful. An attempt was made to compare TRMM 3B42 products rainfalls with surface-based rain-gauge (RNG) rainfall obtained at 31 stations over Bangladesh for the years 1998-2002. Day-by-day rainfall amounts determined by TRMM and RNG are compared for continues 274 days (from 1 March to 30 November) in each year and at every station. Out of 274 days, averaged for 5 years rainfall over 31 stations, 97.08% and 98.91% days are detected as rainy day by TRMM and RNG respectively. Rainy days detected by TRMM matched 95.99% of the same detected by RNG. On an average, TRMM can determine about 98.24% of the RNG rainfall. The TRMM overestimates rainfall during pre-monsoon and underestimates during monsoon while alike during postmonsoon period. Overall, TRMM underestimates rainfall in the heavy-rainfall regions of Bangladesh.