Journal of the Geodetic Society of Japan
Online ISSN : 2185-517X
Print ISSN : 0038-0830
ISSN-L : 0038-0830
Volume 3, Issue 1
Displaying 1-6 of 6 articles from this issue
  • Kazuo MURAOKA, Akira TSUDA, Kazuo KITADA
    1956 Volume 3 Issue 1 Pages 1-7
    Published: June 20, 1956
    Released on J-STAGE: March 01, 2011
    JOURNAL FREE ACCESS
    An interference comparator is constructed for the standardization of a 5-meter standard scale in terms of wave length of light . The interferometer consists of three FabryPerot etalons: 5 cm., 50 cm. and 5 m. ones . Optical multiplication of lengths is executed by spectroscopic method under normally incident ray . Interference rings and fringes are photographed by spectrographs. The present report gives the general description of the apparatus.
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  • -Application to a Problem concerning the Errors in the Geodetic Coordinates of the Japanese Datum Point-
    Tsutomu SHIMIZU
    1956 Volume 3 Issue 1 Pages 8-15
    Published: June 20, 1956
    Released on J-STAGE: July 05, 2011
    JOURNAL FREE ACCESS
    In the first paper, the author has derived a more general formula for the Laplace condition, from which two different equations of conditions for LAPLACE residuals were introduced, the one being suitable for a regional triangulation net and the other for a system of all the nets. This paper concerns the practical application of the latter equation to the Japanese system of the geodetic coordinates. By means of the astronomical results on the recently established LAPLACE stations, thirty-three in all, the errors in the geodetic coordinates of the Japanese datum point were provisionally evaluated by our formula. The numerical results obtained here may not be conclusive, as the observed data were insufficient in number, especially in the south-western part of Japan, and furthermore the horizontal earth-displacements could hardly be eliminated completely. The provisional values, however, are not markedly discordant with the other investigators' previously obtained by the usual method of “the deviations of verticals.” It is to be noted that these two independent treatments have common reference to the physical earth-surface in Japan and not to the “world-wide earth-ellipsoid.” A fact found worthy of some attentionin the course of this study is that the Japanese triangulation-net has been twisted considerably in the Hidaka district of Hokkaido where the deviations of verticals change remarkably from place to place.
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  • Matakichi OMORI
    1956 Volume 3 Issue 1 Pages 16-20
    Published: June 20, 1956
    Released on J-STAGE: March 01, 2011
    JOURNAL FREE ACCESS
    I. Datum Adjustment, Tokyo to Manchuria
    Triangulation survey based on Tokyo datum, Bessel spheroid, extends from Japan to Korea and is tied to the Manchurian triangulation system on Hsinking datum, Bessel spheroid, through 23 common points.
    The adjustment was developed and accomplished from the difference of geographical coordinates (Hsinking minus Tokyo) for these common points . The results are as follows:
    dψ0=-8″.745 dλ0=+16″.829
    K10.-4=+0″.526 dA0=-3″.44
    These are values correlated to the both datums . However, the value for longitude shows considerable discrepancy when compared with the value of systematic error previously known in Tokyo datum.
    Tokyo datum dψ0=+8″.54 dλ0=-6″.54 (Kawabata-1940)
    Hsinking datum dψ0=+0″.254 dλ0=+2″.185 (Omori-1942)
    Tokyo datum — dλ0=-13″.38 (Hirose-1948)
    II. Spheroid conversion, Bessel to International
    Geographical coordinates of 20 1st order triangulation on Bessel spheroid in Taiwan were converted to International spheroid . The B. G. Bonford formula which was slightly modified was used.
    Result of an investigation on accuracy revealed that it is sufficient for conversion of 3rd and lower order triangulation (three decimal places in second, geographical coordinates) .
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  • I. TSUBOKAWA, E. INOUE, H. SUZUKI
    1956 Volume 3 Issue 1 Pages 21-26
    Published: June 20, 1956
    Released on J-STAGE: September 07, 2010
    JOURNAL FREE ACCESS
    A new type high speed recorder for the GSI pendulum apparatus has been designed and constructed. The recorder consists of a crystal clock, a time-signal receiver, an amplifier, a spark chronograph with a power source and an optical device. Light signals from pendulums are transduced to electrical pulses, amplified and recorded by the spark chronograph. Periods of the pendulums are determined by comparing these signals with time marks of 1, 000 cycles per second given by the crystal clock or the JJY time signals. By this recorder, errors due to recording itself will be made less than 10-7, much smaller than those due to the pendulum or any other origins . Therefore, it is expected that detailed knowledges about characteristics of the pendulums, especially of the knife-edge and the supporting plane, will be obtained and the accuracy of the gravity measurement may be ensured and even improved.
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  • T. OKUDA, E. INOUE, H. SUZUKI
    1956 Volume 3 Issue 1 Pages 27-33
    Published: June 20, 1956
    Released on J-STAGE: March 01, 2011
    JOURNAL FREE ACCESS
    Acting on Resolution VII adopted at the meeting of the International Gravimetric Commission at Paris in 1953, measurements of the differences of gravity between C&GS, NBS and GSI were carried out by members of the Geographical Survey Institute. The differences of the accelerations due to gravity were:
    gc&GS-gGSI=+329.8±0.3 (m.e.) mgal
    gNBS-gGSI=+310.4±0.3 (m.e.) mgal
    The result leads to a conclusion; the difference between the present value of gc&GS-gGSI=+328.2 mgal and the above-mentioned is + 1.6 mgal, while that between the present value of gNBs-gust=+310.2 mgal and the above-mentioned is+0.2 mgal.
    In the former case the difference is somewhat too large. According to the personal information from Mr. Rice of the Coast and Geodetic Survey, however, the results of recent relative measurements between C&GS and NBS, obtained by member of the Coast and Geodetic Survey using a Worden gravimeter, showed that the new value of gravity at Commerce Base relative to gNBs (980.100) was almost one milligal high. If this value is used for our relative measurements instead of gc&Gs (980.118), the difference gc&GS-gGSI will be much more closely coincided.
    In the latter case, the difference is far smaller than might have been anticipated from the accuracy of the procedure used by E. Borrass for his first determination of the present value gTOKYO (979.801), to which the adopted value gGSI is refered.
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  • Tokio ICHINOHE, Ichiro NAKAGAWA, Yoko OKAMOTO
    1956 Volume 3 Issue 1 Pages 34-37
    Published: June 20, 1956
    Released on J-STAGE: July 05, 2011
    JOURNAL FREE ACCESS
    Observations of the tidal variations of gravity were made for a month at each of the three stations in Kinki District, i.e. Kyoto, Chikubu-shima, and Shionomisaki. The results of observation were analysed and the tidal factors of M2-component at these stations were obtained as 1.18, 1.21, 1.23, and the phase lags as 1°96, 1°20, 2°42, respectively. From these values it is concluded that the most reliable value of the tidal factor of gravity must be a certain value close to 1.20 and that the phase lag is very small even if it exists. The determination of the exact value of tidal factor is reserved for future research.
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