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Volume 49 (2003)
- Issue 4 Pages 215-
- Issue 3 Pages 159-
- Issue 2 Pages 99-
- Issue 1 Pages 1-
Volume 49, Issue 1
Displaying 1-6 of 6 articles from this issue
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Mikio Tobita2003 Volume 49 Issue 1 Pages 1-23
Published: March 25, 2003
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSSoftware for Synthetic Aperture Radar Interferometry, ″GSISAR″, was developed. It was designed to process JERS-1 SAR data, which were different from data acquired by former SAR sensors in some points, such as (1) STC (Sensitivity Time Control), (2) not good preci sion in orbit information, (3) spike noise, and (4) L-band . Our research object was to obtain the best possible interferograms in both quality, i.e., coherence, and quantity. One of the ef forts to keep quality of interferograms is, for example, the accurate offset estimation algo rithm, which later enabled us to measure 3-D displacement vectors showing ground defor mation associated with criptdome formation in April, 2000 eruption of Usu volcano. Throughcorrelation study using 45 pairs of JERS-1/SAR interferograms, we confirmed that L-band provided better coherence in vegetated area and smaller temporal decorrelation effects than C-band. Therefore L-band is thought to be suitable for SAR interferometry in vegetated and mountainous land like Japan. For intercomparison of InSAR results, we discussed and organized the theory, equations and definitions of SAR interferometry .View full abstractDownload PDF (6003K) -
Basic TheoryChen Chang Yun2003 Volume 49 Issue 1 Pages 25-46
Published: March 25, 2003
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSIn terms of theoretical approach, the number of gross errors and correct positioning were first determined and then an outlier parameter was added to the model to eliminate the influ ences of gross errors. In this paper, it is required that the quadratic estimation should be robust. Under this condition, the Robust Best Invariant Quadratic Unbiased Estimation (RBIQUE), Robust Minimum Norm Quadratic Unbiased Estimation (RMINQUE), and Robust Helmert Estimation (RHE) is derived. All current GPS baseline vector network adjustment software for geodetic surveying uses the baseline vector's variance-covariance matrix pro vided by the baseline processing software. However, the output value of that variance covariance matrix is usually too small, does not match actual errors, and is usually higher than instrument's nominal precision. The GPS network also deforms due to an error in grosserror detection and positioning calculations. Additionally, when the GPS network is undercombined adjustment together with the terrestrial network, it is difficult to suitably determine the weighting ratio between the GPS network and the terrestrial network since the random model of the GPS network is different from actual conditions. To resolve the above issues, a study for a proper method to estimate the random model of GPS baseline vector network isnecessary. We also tried to present a generalized method of transforming a quadratic estimation into a linear estimation. In addition, conclusions of linear estimation were applied to analyze the statistical properties of quadratic estimation.View full abstractDownload PDF (1467K) -
Advance TheoryYun Chen Chang2003 Volume 49 Issue 1 Pages 47-61
Published: March 25, 2003
Released on J-STAGE: March 01, 2011
JOURNAL FREE ACCESSAs for its application, according to error source of geodetic observation vector, we estab lished an error model and a stochastic model for geodetic observation vector to investigate the non-negative estimation possibility of fixed variance and scaled variance components. We concluded that these two types of variance components cannot be estimated at the same time. In order to solve this problem, an alternative algorithm and a united algorithm have been proposed.View full abstractDownload PDF (1056K) -
Theory of Robust Quadratic Estimation and Application to Stochastic Model for Geodetic Network (III)Application to Network AdjustmentChen Chang Yun2003 Volume 49 Issue 1 Pages 63-72
Published: March 25, 2003
Released on J-STAGE: July 05, 2011
JOURNAL FREE ACCESSA computer program has been written on the basis of theories and algorithms proposed in papers I and II. This program was used to perform BIQUE and RBIQUE on stochastic model of geodetic networks, and some useful conclusions have been obtained.View full abstractDownload PDF (874K) -
Ateya I. Lukandu, Satoshi Okuyama, Shuzo Takemoto2003 Volume 49 Issue 1 Pages 73-82
Published: March 25, 2003
Released on J-STAGE: March 01, 2011
JOURNAL FREE ACCESSInterpretations of gravity data suffer from the well-known non-uniqueness of the inversion process and consequently, it demands additional apriori information. The prior knowledge of geology and/or geometry besides appearance of the profiles and contours can make the modeling more tractable. Making use of a subset of parameters consisting of the strike, length, attitude and depth extent of the fault we perform gravity inversion analysis across the Itoigawa-Shizuoka Tectonic Line (ISTL) in the Central Ranges-Japan. As a result, a two dimensional model based on gravity data and consistent with previous works on reflection and/or refraction prospecting is given to depict probable sub-surface structure across ISTL. Seismic experiments suggest a thick sedimentary basin to the Southwest or West of tectonic trace. Similar results are corroborated by our analysis where the sedimentary rocks to the Southwest or West are at depths of 3-3.5 km and the structure narrows westwards.View full abstractDownload PDF (4826K) -
Youich Ooi, Honglin Jin2003 Volume 49 Issue 1 Pages 83-86
Published: March 25, 2003
Released on J-STAGE: September 07, 2010
JOURNAL FREE ACCESSDownload PDF (2509K)
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