巻号一覧
44 巻 (1998)
- 4 号 p. 205-
- 3 号 p. 143-
- 2 号 p. 51-
- 1 号 p. 1-
44 巻, 4 号
選択された号の論文の6件中1～6を表示しています
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仙石 新1998 年 44 巻 4 号 p. 205-222
発行日: 1998/12/25
公開日: 2011/03/01
ジャーナル フリーPrecise modeling of forces acting on artificial satellites has become necessary due to recent progress in space geodetic techniques. The significance of surface force, whose magnitude is proportional to the satellite surface area, was recognized in the last decade through LAGEOS anomalous along-track acceleration. This paper reviews research activities on surface force modeling of satellites for geodesy. Air drag, the dominant surface force for a low-altitude satellite, is still a problem due to its large variability and the unpredictability of atmospheric density. The modeling of solar radiation pressure is a key for obtaining precise ephemeris of a high-altitude satellite since solar radiation pressure is the largest surface force. The anisotropy of radiation pressure has to be considered for geodetic, navigation, and altimeter satellites. The thermal thrust due to re-emission of heat from the satellite's surface significantly affects the orbit. The studies on surface forces acting on Ajisai are briefly reviewed. It should be noted that knowledge of the satellite's spin axis orientation is essential in surface force modeling, even for nearly spherical satellites. To reduce errors in the non-gravitational force models, the optical and thermal surface properties of future geodetic satellites must be designed to be spherically or axially symmetric and be thoroughly tested before launch.抄録全体を表示PDF形式でダウンロード (3266K) -
黒石 裕樹1998 年 44 巻 4 号 p. 223-236
発行日: 1998/12/25
公開日: 2010/09/07
ジャーナル フリーEstimation of surface gravity at benchmarks is discussed for computing Helmert heights in Japan. A 3' x 3' grid of real Bouguer anomalies (Kuroishi, 1995) is used to restore surface gravity values. In comparison with the bilinear interpolation, we employ the biquadratic interpolation method to estimate real Bouguer anomalies at benchmarks. RMS discrepancies between the estimated and the observed gravity at 9, 329 benchmarks are found to be 2.5 mgal, which is comparable to RMS variations of 2.9 mgal in gravity within 3' x 3' cells and to RMS errors of 2.2 mgal of 3' x 3' grid anomalies. The heights of all national benchmarks distribute with a RMS value of 179.40 m and 95 percent of them are below 500 m. Under the assumption of no correlation among estimated gravity values, the RMS error induced from gravity estimation errors is expected to be 0.6 mm. Sample computations of differences of Helmet heights between with the observed and with the estimated gravity are carried out for leveling routes 187 and 204, which are considered to be of the biggest Helmert correction lines: the former includes the highest benchmark at Nomugi Pass and the latter runs from Matsumoto, Nagano to Itoigawa, Niigata. The results show 6 mm at the maximum difference and the errors in Helmert heights are expected to be less than 10 mm. That is comparable to the error of the Helmert height system and the estimated gravity, therefore, is precise enough to compute Helmert heights in Japan.抄録全体を表示PDF形式でダウンロード (1484K) -
向井 厚志, 藤森 邦夫, 石井 紘, 中尾 茂, 松本 滋夫, 平田 安廣1998 年 44 巻 4 号 p. 237-248
発行日: 1998/12/25
公開日: 2010/09/07
ジャーナル フリーIn 1996, an 800 m borehole was drilled near the Nojima fault on the northwest Awaji Island in order to observe crustal activity. It is expected that crustal deformation related to movement of the fault can be observed with a high S/N ratio because an instrument was installed at the depth of 800 m. We analyzed the observational data obtained from May 1996 to August 1997 and investigated characteristics of long-term change, annual change and tidal changes of the crustal deformation. Major part of long-term changes of strain and tilt show northeast southwest extension and southwest subsidence. It is possible to interpret that the long-term changes were caused by postseismic crustal movement after the 1995 Hyogoken-Nanbu earthquake. Annual changes of strain and tilt show mainly east-west extension/contraction and northwest uplift/subsidence. These annual changes might be related with groundwater. Tidal factors of strain and tilt varied on December 1996. It is considered that these changes were caused by a redistribution of the groundwater due to a modification of the observational system.抄録全体を表示PDF形式でダウンロード (3155K) -
日本測地学会賞坪井賞制定の覚書瀬川 爾朗1998 年 44 巻 4 号 p. 249-253
発行日: 1998/12/25
公開日: 2010/09/07
ジャーナル フリーPDF形式でダウンロード (1568K) -
橋本 学1998 年 44 巻 4 号 p. 253-254
発行日: 1998/12/25
公開日: 2010/09/07
ジャーナル フリーPDF形式でダウンロード (341K) -
我が国の測地基準系の世界測地系に基づく再構築(提言)1998 年 44 巻 4 号 p. 259-260
発行日: 1998/12/25
公開日: 2010/09/07
ジャーナル フリーPDF形式でダウンロード (269K)
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