Abstract : This interim technical report contains a tropospheric system prediction model which can be used to predict median path loss, aperture to medium coupling loss, and 2 sigma multipath spread. The prediction model is used to determine design parameters for an angle diversity system. For a dual vertical angle diversity system the optimum beam separation is approximately 1 beamwidth and the antenna take-off angle relative to the horizon is approximately 1/2 beamwidth for C-band systems and 1/4 beamwidth for L-band systems. An analysis of long term variability and the decorrelation advantage of angle diversity is presented along with preliminary results. The prediction model is used to compare 3 specific troposcatter system examples with the result that dual space/dual angle diversity is superior in system performance over conventional dual space/dual frequency diversity. The dependence of aperture- to-medium coupling loss on carrier frequency is also investigated. The turbulent scatter theory used in the model analysis suggests that conversion of L-band systems to S-band would result in significant system improvement. Further study of available empirical data is required to validate this result.