Lineaments observed from LANDSAT imagery have much more geological significance when they are longer and more straight. The line pair method was proposed in this paper in order to extract such longer lineaments. In this method, local statistics calculated from pixels on the orthogonal line pair centered on each pixel are used. From several experiments, the line pair method was found to be able to estimate considerably large areas with relatively small amounts of computations.
This method was applied to a geological interpretation of a LANDSAT image of the middle part of Korea. In this experiments, it was found that the length and the rotation angle of the orthogonal line pair have much influence on the result. In order to get the best result, a method of choosing the proper line length and the rotation angle was investigated.
As a result, this method was proved to be very useful for the recognition of structural elements such as faults and other geological boundaries, etc.

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In order to teach and work effectively at survey and photogrammetry, one should understand basic semiological abbreviations which derived form foreign languages to Japan. This paper describes that several technical abbreviations in surveying correspond closely with Dutch words which were imported into Japan in the Edo era (1600-1867) .It was considered that, as established theory, symbols“B”and“L”were German abridgments of“Breite”and“Länge” (i.e. latitude and longitude), respectively, by force of making an amendment form French triangulation system to German triangulation system which had employed by the military serivice of Japan in 1882.Nevertheless, “B”and“L”also coincide with Dutch terms of“breedte”and“lengte..which were transfered to Japan at least since 1803. Moreover, it reveals that symbols“B”, “P”and“C”being utilised for eccentric triangulation might be said as abridgments of Dutch terms form“bevordelijk standpunt”for instrumental center, “piramidaale centrum”for center of measuring tower (namely“pyramid”) and“centrum van geodesische monument”for center of hurried mark, respectively.

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A rapid digital image processing method for converting Landsat imagery to perspective land scenes is presented.
In order to shorten the processing time, elevation data of DTM is transformed into image data and the processing procedure is divided into two stages; at first stage, elevation image and B.G. and R image are twodimensionally processed and at the second stage, perspective scene is reconstructed by the overwritting method which automatically eliminates hidden pixels.
The processing time for perspective image of full color is reduced to about one half compared with ordinary pixel-to pixel transformation. A sequence of synthesized images of Mt. Yotei near Sapporo is shown, which is viewed from various view points and also a simulated image of flood is presented as an application of perspective images.

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Several studies on geometric correction of LANDSAT MSS imagery have been developed. Those methodologies are classified into three: 1) system correction with satellite data only, 2) black box type correction with ground control points only and 3) combined method with system correction and black box type correction. The third method has been pointed out as the best method in accuracy and computing time. However, this method shall be improved into the one with simultaneous solution since the current method is composed of two steps solution, that is, system correction in the first step and black box type correction in the second step.
The objective of the study is to develop a simultaneous solution by treating the position and attitude of satellite as the unknown variables, which will be determined by ground control points and approximate observed satellite data.
In order to determine those unknown variables, so called colinearity equation which is utilized as the basic principles in photogrammetry, is defined as a function of time. Nineteen unknown variables in total have been determined in this study.
The final goal of geometric correction is to rearrange and resample the image data into the array of map coordinate system. From the results of analysis of influence upon the image distortion resulted from variations of position and attitude of satellite, and scan mirror velocity, the geometric distortion within a subdivided area with 350 pixels and 78 lines can be considered to change linearly with not more than 0.2 pixel's distortion.
In this study the geometric correction including resampling for a scene of LANDSAT MSS imagery was accomplished in about seven minutes by using FACOM M-180 AD (12 MB memory) . This result shows to be better in accuracy and computing time as compared with the results obtained from the existing methods.

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Projective distortions due to terrain reliefs considerably deteriorate image correlation in stereo matching. This paper covers the derivation of the relationship between the ensemble mean of sample crosscovariances, usually used as a matching criterion, and projective distortions, in terms of correlation window size and a power spectral distribution of image densities, and further discusses their effects on correlation mathematically. In addition a simple correlation test is appended to verify the validity of the discussion. The main resulth sbtained through the discussion are as follows:
•A correlation window works as a high-pass filter cutting off the lower frequency components of spectrum, wavelength of which is shorter than a half of window size.
•Projective distortions distort the higher frequency components and deteriorate correlation, Hence, for obtaining precise matching performance, recursive correlation procedure accompanied with step-by-step corrections of distortions will be essensial in ony practical matching strategy.
•At the corners of the film exposed by a wide-angle camera, it may occur that a projective distortion caused by more than 45° slopes exceeds an allowable limit.

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