In analytical orientation for a pair of two-medium photographs we have two ways; the one is the way to devide the orientation in two phases, relative and absolute orientation, and the other is the way to calculate the outer orientation elements of individual photographs according to the orientation theory in single photogrammetry. The researches of the first way have been carried out by K. Rinner^{1), 2)} , B. Schmutter and L. Bonfiglioli³⁾ , and A. Okamoto and J. Höhle⁴⁾ , and also various methods were developed. But as shown in the reference⁴⁾ , these methods have a disadvantage that the obtained accuracy is rather unsatisfied on account of the great correlations between the relative orientation elements and that some corrections are necessary to the result. Therefore, the orientation theory of individual photographs is to be considered to carry out the orientation of two-medium photographs effectively and two new methods are developed in this paper.
The ground coordinate system is usually selected in carring out the orientation of individual photographs. Therefore, we have only to determine the outer orientation elements of individual photographs, when the refractive surface is given. It follows that the correlations between the unknowns are reduced. This is a great advantage of the methods proposed. The further advantage of the methods is that we can use them easily, even if the refractive surface is curved and unknown.
These two methods were tested with three experimental models and proved to have a fairly good accuracy.

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In case of short range photogrammetry, the uneliminated vertical parallax often exists in order about a few ten microns and also no good precision results can be obtained. One of the most occurable cause is unsuitable interior orientation elements of the used camera. In photogrammetry, I hope the camera to be used in its best condition. In this paper I show the method for measuring the interior orientation elements analitically. It is based on the central projective relationship between the XYZ coodinate value in object space and the corresponding xy coordinate value in its image space.
And also this method is confirmed by using the simulation model mathematically.

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The objectives of the study are stressed on the studies on the errors in volume calculations of earth works by using the mesh method, and on the criteria for determining the optimum mesh intervals.
A test area was applied forr the study in which five different mesh intervals, 5m, 10m, 15m, 20m, and 30m were sampled for the volume calculation.
The results suggest that both absolute error, relative error and the ratio of volume error to the area should be considered in the case of the analysis of errors in volume calculation.

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In the River Mibu Basin, it was numerical analyzed to the relation between landslide degradation volume and the factors of rainfall, slope, river density and vegetation.
For this study, 500M Grid was covered on the River Mibu Basin, and these factors were surveyed in every grid field.
We expressed the relation by function, and obtained the function of coefficient.
Using this function, we can be forecast some landslide degration volume according to rainfall in the area.

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[in Japanese]

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Ultrasonic imaging systems, using three types of image converters, have been developed. The advantages of an Al-suspension cell converter are high resolution, high sensitivity and simple cell structure. The prototype of Al-suspension cell ultrasonic imaging system was constructed and underwater experiments has done.
The advantages of ultrasonic image converter tube are universality of an electric system, high sensitivity and fast response time, but as it's disadvantages are small target size and weak pressure endurance, it has not been applied to various field.
The advantages of piezo-electric transducer array converter are high sensitivity and fast response time and strong pressure endurance.
The principle of the converters is explained and some examples of the ultrasonic image are shown.

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