New satellite sensor and method for the direct measurement of the planetary albedo, results for 1999, 2000 and 2001 in South America

The second satellite of the Brazilian Complete Space Mission (SCD2/MECB) was launched on October 23, 1998 and it hosts a solar cell experiment. The solar cell senses visible radiation (400–1100 nm) and permits the simultaneous inference of direct insolation and the insolation that is reflected outside of the earth. The global albedo is obtained using the ratio between these two values after spherical angular corrections. The SCD2 has a circular orbit 750 km high and its spin is 35 rpm. lar cell data are transmitted in real-time and received by the ground station of Cuiabá, MT-Brazil (16°S, 56°W), which limits their spatial coverage to South America. The albedo data can be grouped in periods of time (annual, seasonal or monthly) or studied for several places during the orbit time. A new method to obtain the planetary albedo is tested through a numerical simulation using the data (cloud and land area) extracted from a GOES image. The solar cell experiment albedo values are shown as a function of SCD2 satellite orbit time to six local in South America. The values are in the range between 6% and 68%. The statistic analysis of the main values (minimum, maximum, mean and deviation) is done for 1999, 2000 and 2001. The results show several climate characteristics. For example, Recife-PE (8°S, 35°W) has good weather nearly all-year round. São Paulo (24°S, 47°W), in contrast, is famous for weather instability, with temperatures governed by cold fronts that come suddenly from the south. scribed method for evaluating the planetary albedo of the earth starts from a simple and relatively inexpensive experiment and does not rely upon sensor calibration because the measure is self-calibrated by the simultaneous reading of both irradiation peaks, namely, from the sun and its reflection by the earth, during each spin of the satellite.