A method to calculate the atmospheric transmission of the laser radar beams has been developed for use in systems analysis. The two way transmission is derived in closed form for the neodymium-glass and the carbon dioxide lasers. This study utilizes the optical properties by previous researchers to obtain a function which can be integrated from the laser radar altitude to the object altitude. The closed form solution facilitates the calculation of the two way transmission of a laser radar with a line of sight oriented horizontally, upwards or downwards. Mathematical constants for the attenuation coefficient are presented for use in calculating other altitude cases. The method can be easily applied to other laser radar frequencies.