A NEW METHOD FOR IMPROVING THE INTERFEROMETRIC RESOLUTION BY COMPENSATING FOR THE ATMOSPHERICALLY INDUCED PHASE-SHIFT

Electromagnetic waves traveling through the atmosphere experience an a dded phase shift due to the presence of various gases. Since the water vapor distribution in the atmosphere has a significant spatial and te mporal variance, the corresponding phase shift can cause a serious deg radation of the maps produced by radio interferometers. This study pre sents the calculation of the atmospherically induced phase shift in te rms of ground based measurements and introduces a new technique to com pensate for it. The compensation technique is implemented on the Berke ley-Maryland-Illinois Array at Hat Creek, California, and various test s are performed to demonstrate the accuracy of the technique. Finally, some future work is suggested.