NOAA Satellite performance in estimating rainfall over the Island of Lombok

Abstract

Rainfall data is the main input data for use in hydrological analysis, especially for planning purposes. Rainfall data is usually obtained from observations through rain stations. However, the availability of rainfall recording stations is sometimes very limited and located far from the project location. Water resource projects often face this obstacle. A technique is needed for estimating rainfall data using rain data from remote sensing through weather satellite data information providers. Since rainfall data from satellites is not the real amount of measured rainfall on the land, the rainfall data from the satellite must still be evaluated as to whether it can be directly used to represent the rainfall data of a region. The aim of this study is to evaluate the validity of NOAA CPC daily total precipitation data by comparing it to measured rainfall data and to analyse the lag time using the cross-correlation method. The results showed that the NOAA data has a lag time of +1 day over Lombok Island. The rain estimated by NOAA positively correlated with gauged rainfall on the next day. However, the performance of the NOAA data was very poor and for prediction purposes, the data still need to be calibrated.