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Geostationary satellites provide measurements over a wider geographical area with high temporal sampling, while microwave measurements are more accurate but sparse. For continuous monitoring of the Indian monsoon, geostationary platform would be ideal. In this study, INSAT (Indian National Satellite) Multi-spectral Rainfall Algorithm (IMSRA) has been used for the estimation of rainfall from Kalpana-1 very high resolution radiometer (VHRR) measurements. IMSRA benefits from the relative advantages of infrared and microwave sensors and is operational at the India Meteorological Department (IMD). In this paper, rainfall is estimated over India at meteorological sub-divisional scale during the south-west monsoon season of 2009 using Kalpana-1 satellite measurements. This is the first experimental attempt to generate meteorological sub-divisional scale rainfall maps using Kalpana-1 satellite measurements. The rainfall maps for the south-west monsoon season over the Indian land region are successfully utilised as a space input for the drought monitoring of the year 2009. The results have been compared with the IMD gauge-based accumulated rainfall maps at monthly and seasonal time scales. The qualitative comparison suggests that rainfall maps generated using the present methodology is in good agreement with the IMD rainfall maps. The quantitative comparison of the sub-divisional monthly accumulated rainfall shows a correlation of 0.77 and standard error of 71 mm over the non-orographic regions, whereas a correlation of 0.60 and standard error of 117 mm is observed over the orographic regions. The present study shows that Kalpana-1 satellite-based rainfall estimates (IMSRA technique) can act as a complementary tool for the monsoon monitoring over the Indian meteorological sub-divisions and can be used for various meteorological and hydrological applications.

In this study, long-term changes in the summer monsoon rainfall over the west coast of India and adjoining eastern Arabian Sea (WCA) have been examined independently using rain gauge adjusted multisatellite rainfall data available since 1979. Present analysis using the satellite-based rainfall data agrees with the long-term rainfall decrease reported in the earlier studies. However, close examination of the data reveals that the rainfall in the recent years (since 2002) has started increasing over the WCA. Hence, it is stressed that a detailed analysis using the satellite-derived rainfall data of longer period is required to arrive at a firm conclusion.

The major scientific objective of the Megha-Tropiques (MT) satellite, an Indian Space Research Organisation (ISRO)–Centre National d'Etudes Spatiales (CNES) collaborative project, is to understand the energy and water cycles in the global tropical region. With its 20° inclined orbit, it will frequently measure radiation emitted by the Earth-Atmosphere System in the visible, infrared and microwave spectrum through its four sensors on board. Various geophysical parameters, namely water vapour, cloud liquid water and surface winds over oceanic regions, and the rainfall, humidity profile and top-of-atmosphere radiative fluxes over land as well as over oceanic regions will be derived from the measurements made by these instruments. This article deals with the efforts made by ISRO to develop algorithms for deriving these geophysical parameters from the microwave imager and sounder, mentioning the pre-launch specifications with prelude examples from existing space-borne sensors of similar types. The sensor-specific algorithms are presented in different sections. Copyright © 2012 Royal Meteorological Society

Summary Vitamin losses during processing of cereal grains and their food products play an important role in human vitamin intake. Therefore, experiments were conducted to optimise the baking parameters for chapati, a flat unleavened, hot-plate-baked product of Asian diet. In the experiments, whole-wheat flour (100% extraction rate) was used for the preparation of chapaties. Central composite rotatable design with three independent variables (thickness of dough sheet, time as well as temperature of baking) at five levels and nine dependent variables, i.e. vitamin B1 and B2 content, textural properties and overall acceptability scores, were used to conduct the experiments. The ranges for three independent variables were: thickness, 2.5–4.5 mm; time, 2.0–3.0 min; and temperature, 200–240 °C. Thickness of the dough sheet had a significant (P ≤ 0.05) positive effect on vitamin retention, while the temperature had greater negative effect as compared with the time of baking. Based on compromise optimisation, optimum conditions for baking of chapati, especially with respect to vitamin retention were: thickness of dough sheet 3.2 mm, time of baking 2.1 min and baking temperature 216.3 °C.