High Spatial Resolution Solar Radio Observations

The Brazilian Decimetric Array (BDA), under development in collaboration with various national and international institutes, will have high spatial and time resolutions of ∼ 5 sec of arc at 5.0 GHz and 100 ms respectively when completely. The BDA will have the capability to observe solar and non-solar phenomena in the following radio protected bands: 1.2-1.7, 2.7 and 5.0 GHz. The sensitivity estimates show that the BDA will have rms sensitivity of 3 mJy at 21 cm for a system temperature of 50 K, using low-noise amplifiers. The final version of the BDA will be an interferometer array consisting of 38 parabolic antennas of 5 meters diameter with a compact ``T'' shaped array at the centre having 32 antennas. The array will be located at Cachoeira Paulista (Longitude - 45° 0' 20'' W, Latitude -- 22° 41' 19'' S) being developed at INPE as an international collaborative program. Various combinations have been investigated for BDA configuration. The Central T with dimensions of 400x180 meters using a randomly distribution of antennas seems to most suitable from point of view of available land and funds. This Central T will have spatial resolution ∼ 2x3 arc minutes, field of view of ∼ 3 degrees and side lobes are minimized below 20 percent of the main lobe. The UV coverage of this configuration and synthesized beam pattern will be presented. Also will be presented simulation of imaging capability of this array using Nobeyama data at 17 GHz.