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PENGEMBANGAN JARING KONTROL GEODESI PEMANTAU WADUK SERMO Waliyanto, Waliyanto; Widjajanti, Nurrohmat; Yulaikhah, Yulaikhah; Taftazani, M. Iqbal
GEOMATIKA Vol 21, No 2 (2015)
Publisher : Badan Informasi Geospasial in Partnership with MAPIN

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (561.113 KB) | DOI: 10.24895/JIG.2015.21-2.581

Abstract

Keberadaan Waduk Sermo di Kabupaten Kulonprogo, sangat penting karena manfaatnya sebagai tampungan air bersih, sarana pariwisata dan saluran irigasi untuk lahan pertanian di sekitarnya. Namun demikian banyak juga yang tidak menyadari bahwa di bawah Waduk Sermo terdapat segmen sesar aktif yang memanjang dari Parangtritis ke Kulonprogo. Penelitian ini bermaksud untuk mengembangkan jaring pengamatan yang telah ada sebelumnya menjadi lebih luas cakupannya untuk mengetahui dampak dari adanya sesar aktif tersebut. Penelitian dilaksanakan dengan beberapa tahapan, yaitu: 1) pengembangan kerangka kontrol, dengan menambah tujuh titik (5 makro dan 2 mikro) jaring kontrol baru; 2) pengukuran kerangka kontrol, dengan menggunakan pengamatan GPS/GNSS metode relatif statik di semua titik kontrol sejumlah 15 titik; 3) pengolahan data, dengan menggunakan perangkat lunak GAMIT/GLOBK dan diolah dalam dua skenario terkait penggunaan titik referensi dalam pengolahan. Hasil dari penelitian ini adalah terbangunnya pilar/patok jaring pemantauan baru sebagai pengembangan jaring kontrol pemantauan Waduk Sermo, serta koordinat jaring kontrol hasil olahan dalam dua skenario, yaitu: pada skenario pertama, titik makro memiliki simpangan baku terkecil yaitu 0,004 m pada sumbu Z di titik MAK2. Sedangkan pada titik mikro, simpangan baku terkecil sebesar 0,004 m pada sumbu Z di titik BBR1 dan BMS2. Pada skenario kedua, simpangan baku titik makro terkecil yaitu 0,001 m pada sumbu X di titik MAK1. Sedangkan pada titik mikro, simpangan baku terkecil sebesar 0,005 m pada sumbu Z di titik BMS2. Titik-titik yang sudah dibangun dapat bermanfaat untuk memantau pergerakan bendungan dan secara berkala bisa digunakan untuk memantau aktivitas sesar yang berada di bawah Waduk Sermo.Kata kunci: pengembangan JKG, pemantau Waduk Sermo, teknik GPS/GNSS
GEOMETRIC ASPECTS EVALUATION OF GNSS CONTROL NETWORK FOR DEFORMATION MONITORING IN THE JATIGEDE DAM REGION Sanjaya, Made Ditha Ary; Sunantyo, T. Aris; Widjajanti, Nurrohmat
International Journal of Remote Sensing and Earth Sciences (IJReSES) Vol 15, No 2 (2018)
Publisher : National Institute of Aeronautics and Space of Indonesia (LAPAN)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1322.407 KB) | DOI: 10.30536/j.ijreses.2018.v15.a2901

Abstract

Many factors led to dam construction failure so that deformation monitoring activities is needed in the area of the dam. Deformation monitoring is performed in order to detect a displacement at the control points of the dam. Jatigede Dam deformation monitoring system has been installed and started to operate, but there has been no evaluation of the geometry quality of control networks treated with IGS points for GNSS networks processing. Therefore, this study aims to evaluate the geometric quality of GNSS control networks on deformation monitoring of Jatigede Dam area. This research data includes the GNSS measurements of five CORS Jatigede Dam stations (R01, GG01, GCP04, GCP06, and GCP08) at doy 233 with network configuration scenarios of 12 IGS points on two quadrants (jat1), three quadrants (jat2), and four quadrants (jat3 and jat4). GNSS networks processing was done by GAMIT to obtain baseline vectors, followed by network processing usingparameter method of least squares adjustment. Networks processing with least squares adjustment aims to determine the most optimalĀ  by precision and reliability criterion. Results of this study indicate that network configuration with 12 IGS stations in the two quadrants provides the most accurate coordinates of CORS dam stations. Standard deviations value of CORS station given by jat1 configuration are in the range of 2.7 up to 4.1 cm in X-Z components, whereas standard deviations in the Y component are in the range 5.8 up to 6.9 cm. An optimization assessment based on network strength, precision, and reliability factors shows optimum configuration by jat1.
SISTEM TINGGI DALAM REALISASI KADASTER 3D DI INDONESIA: TANTANGAN, PERMASALAHAN DAN ALTERNATIF SOLUSI Widjajanti, Nurrohmat
BHUMI: Jurnal Agraria dan Pertanahan No 38 (2013): BHUMI
Publisher : Pusat Penelitian Dan Pengabdian Kepada Masyarakat Sekolah Tinggi Pertanahan Nasional

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (600.869 KB) | DOI: 10.31292/jb.v1i38.170

Abstract

One important componentin the3Dcadastral system isthe definition of height component. The height of a cadastralobjectis the height above a certain height reference field. Based on theconceptandits use, there aremany height reference fields.Each reference field will have a certain effect on the type of height system and on the corresponding precision. Theabsoluteheightisdefinedin reference to thenationalheight reference, which provides certaintyandcleargeometricandtopologicalrelationsfor3Dcadastralobjects. However, the ideal nationalheight reference field,in this case precisegeoidmodels has not been definedfor thewhole of Indonesia.An alternativesolution to the problem uses a definition ofalocalgeoidmodel or the use ofa high-resolutionglobalgeoidmodel, the EGM2008. In the implementation, the precision level ofthe available geoid model and the required precision level of cadastral objects height become the basis for the selection of ageoid model. The use ofthe geoid modelasthe height reference has also an impact on theoptimalization/development of theapplication of BPNCORSstationsthatcan beusedas ahorizontal as well as a verticalreferencepointin3Dcadastralmapping.Keywords: 3D cadastre, cadastral mapping, geoid.
The Effect of Baseline Component Correlation on the Design of GNSS Network Configuration for Sermo Reservoir Deformation Monitoring Yulaikhah, Yulaikhah; Pramumijoyo, Subagyo; Widjajanti, Nurrohmat
Indonesian Journal of Geography Vol 51, No 2 (2019): Indonesian Journal of Geography
Publisher : Faculty of Geography, Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (71.575 KB) | DOI: 10.22146/ijg.44914

Abstract

The condition of the geological structure in the surrounding Sermo reservoir shows that there is a fault crossing the reservoir. Deformation monitoring of that fault has been carried out by conducting GNSS campaigns at 15 monitoring stations simultaneously. However, those campaigns were not well designed. With such a design, it took many instruments and spent much money. For the next GNSS campaign, it should be designed so that the optimal network configuration is obtained and the cost can be reduced. In the design of deformation monitoring network, sensitivity criteria become very important for detecting the deformations. In GNSS relative positioning, the baseline components are correlated, but this correlation is often ignored. This research examined the effect of baseline component correlations on the design results of the GNSS configuration of the Sermo Fault network based on sensitivity criterion. In this case, the western side of the fault was taken as a reference, while the other side as an object moving relatively against the western side. This study found that the baseline component correlation affects the results of GNSS network configuration. Considering the correlation could result a sensitive network configuration with a fewer baseline; therefore, the cost and time of field surveys can be reduced. It can be said that the baseline component correlation needs to be taken into account in the configuration design of deformation monitoring network.