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.

Tolerance of Chain Contact Pitch and Chain Length in the New Edaphic and Mineral Chain Ditcher;

The formulas concern two kind of saw chains with same pitch and different pitch and three kind of sprockets,which are rim sprocket,spur sprocket and nose sprocket.

Based on study and precision analyses on the outer diameter and pitch measure of the synchronization belt-wheels,the paper considers that standard offset can be measured only by using ordinary tools and effective and dependable result obtained.