The lack fidelity of the slant range on ground layer exists in progress of using the L wave band meteorological sounding system because of the situation which is distorted the ground echo influence.

One is the formula for reduction to the mark center of slope distance,another is the formula for vertical angle.

Then the zenith distance and slope distance can be worked out even if the effects of erect refraction of atmosphere does exist, thus extending the adaptability of zenith distance and enhancing its accuracy in trigonometrical leveling.

Objective The aim of this study is to establish a quantitative method for diagnosing the ankle instability in acute injury of lateral ligaments through measuring the normal value of the talar tilt angle of ankle joints.

Objective This article is to clarify the relationship between talar tilt angle and the chronic instability of the lateral ankle , so as to offer a method of quantitative diagnosis about the chronic instability of the lateral ankle.

Based on the experience gained from the development of a long focus, oblique, real_time, aerial camera, it is pointed out that the camera maybe out of focus is due to changes in temperature, atmospheric pressure and oblique photographic distance.