Comparison of two bias correction methods for TRMM 3B42 satellite daily rainfall estimates over Northern Tunisia

The overall objective of this study is to evaluate and correct the Tropical Rainfall Measuring Mission (TRMM) 3B42 algorithm for Northern Tunisia focusing on heavy rainfall events. Two types correction methods are tested. first combined scheme (CoSch) which was applied in two different ways. CoSch (1) combines satellite data with interpolated situ data. However, (2) a not map where pixel value randomly selected from stations belonging pixel. second type best linear unbiased estimator. period January 2007 August 2009. database composed an average 318 rain gauges. Heavy events defined as those daily exceeding 50 mm/day at least one station. A total 77 result selection criterion; 35 were recorded during dry (May October) 42 wet season (November April). We investigate boxplots various evaluation indicators raw TRMM. achievement moderate worst performance very light Moreover, we noticed that TRMM estimates perform better season. error decomposition underlined highest underestimated values localized orographic areas Le Kef, also Cap Bon. overestimation appeared central part area (Bizerte Zaghouan). About bias method comparison, showed stronger than estimator outperforms (2). As TRMM, reports correlation probability detection (POD) more important reaching 0.9 by methods. threat score (TS) coefficients found sensitive whatever method.