Wedyanto Kuntjoro
Geodesy Research Division, Faculty of Earth Sciences and Technology, Institut Teknologi Bandung, Ganesa 10, Bandung, 40132, West Java, INDONESIA

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Journal : Indonesian Journal of Geospatial

Ketelitian Model Kinematik untuk Memprediksi Karakteristik Longsor (Studi Kasus : Zona Longsor di Ciloto-Puncak, Jawa Barat) Sadarviana, Vera; Z. Abidin, Hasanuddin; Kahar, Joenil; Santoso, Djoko; K, Wedyanto
Indonesian Journal of Geospatial Vol 1, No 1 (2012)
Publisher : Indonesian Journal of Geospatial

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Abstract

Abstract. The geodetic approach based on extraterrestrial survey measurements can be used to study phenomenon, especially to monitoring of material movement characteristic. Landslide is one of prominent catastrophe that continuously affecting in Indonesia, especially in rainy season. In mountainous terrain and areas of steep slope of Indonesia, landslides are frequent, especially where land cover has been removed. Landslides destroy not only environment and property, but usually also cause deaths. Landslide mitigation is therefore very crucial and should be done properly. The velocity and acceleration of several monitored point covering the landslide zone area can be estimated using the geodetic approach. Knowing the relation among these three variables in spatial and temporal domain will be useful for identifying the characteristics of landslide. This information can then be used for better strategy of landslide hazard mitigation. Accuracy of the use of kinematic models for prediction of avalanche characteristics need to be validated so that mitigation will be done correctly. Validation is done by doing a comparison between model predictions and the size of the data and statistical tests for the feasibility of prediction of each point of the GPS monitor. Validation is known that the predicted results at some GPS monitor point is not suitable for use. With the vector of the movement of materials, we know the direction and scalar, velocity and acceleration of material displacement. The movement of landslide materials at Ciloto Zone dominated north-west to south-easterly direction and speed to slow very slow (creep). Keywords: accuracy, characteristics, kinematic model, landslide.
Temporal Variation Analysis From Troposphere Delay Using GPS (Study: Bandung, Indonesia) Pradipta, Dhota; Kuntjoro, Wedyanto; Prijatna, Kosasih
Indonesian Journal of Geospatial Vol 1, No 1 (2012)
Publisher : Indonesian Journal of Geospatial

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Abstract

Abstract.Tropospheric delay is the amount of distortion caused by the deceleration of satellite’s signal propagation due to the influence of troposphere. The value of this delay is certain effect of elevation angle that is called the slant delay. In the processing of GPS signals correction, the value of slant delay will be converted using a mapping function to the measured value of the zenith delay which became known as the Zenith Total Delya (ZTD). Zenith value is an accumulated value of the tropospheric delay along the signal’s path at the zenith direction. The value of ZTD can be determined by GPS technique. In Geodesy, ZTD is a nuisance parameter, but for meteorology, it is a parameter of interest, which causes from variability of the atmospheric constituens. The section of ZTD, i.e. Zenith Wet Delay (ZWD), could be derived by substracting Zenith hydrostatic Delay (ZHD) component from ZTD. By surface temperature readings at the GPS receiver, the retrieved ZWD can then be transformed with additional uncertainty into an estimate of the Precipitable Water Vapor (PWV). The aim of this research is to study temporal behavior of PWV at ITB campus, as it is revealed from GPS measurements. According to the research that has been conducted, we obtained some results, i.e. The data quality and strategy which were used in processing could affect the result, In particular, we found that, within 20 minutes, maximum and minimum PWV values could reach 85.2 mmand 6.4 mm, respectively. It may indicate that the atmosphere above the studied are varies highly. Temporal condition in observation point that appears in result such as at 12.00 – 18.00 WIB often shows significant irregular anomalies of PWV that influenced local area observation. Keywords: GPS, PWV, temporal analysis, ZTD. 
Determination of ZNHD based on GPS Data, Radiosonde, and Numerical Weather Model Susilo, Susilo; D. Wijaya, Dudy; Kuntjoro, Wedyanto; Efendi, Joni
Indonesian Journal of Geospatial Vol 1, No 2 (2012)
Publisher : Indonesian Journal of Geospatial

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Abstract

Abstract. Water vapor is a principal element in the thermodynamics of the atmosphere and plays an important role in clouds condensation, which eventually can affect the radiative energy balance. Water vapor cobservation is essential for monitoring global/regional scale of weather and climate changes. However, high variation of water vapor concentrations makes it difficult to observe accurately using the conventional meteorogical observation technique (radiosonde), which is limited in both space and time. Nowadays, accurate observation of water vapor can be accomplished by the Global Positioning System (GPS). In this research, we use 14 continuous GPS stations from Bakosurtanal to observe temporal characteristic of water vapor concentration over West Java region.Keywords: GPS, NCEP, radiosonde, topographic, ZNHD
Ketelitian Model Kinematik untuk Memprediksi Karakteristik Longsor (Studi Kasus : Zona Longsor di Ciloto-Puncak, Jawa Barat) Vera Sadarviana; Hasanuddin Z. Abidin; Joenil Kahar; Djoko Santoso; Wedyanto K
Indonesian Journal of Geospatial Vol 1 No 1 (2012)
Publisher : Indonesian Journal of Geospatial

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Abstract. The geodetic approach based on extraterrestrial survey measurements can be used to study phenomenon, especially to monitoring of material movement characteristic. Landslide is one of prominent catastrophe that continuously affecting in Indonesia, especially in rainy season. In mountainous terrain and areas of steep slope of Indonesia, landslides are frequent, especially where land cover has been removed. Landslides destroy not only environment and property, but usually also cause deaths. Landslide mitigation is therefore very crucial and should be done properly. The velocity and acceleration of several monitored point covering the landslide zone area can be estimated using the geodetic approach. Knowing the relation among these three variables in spatial and temporal domain will be useful for identifying the characteristics of landslide. This information can then be used for better strategy of landslide hazard mitigation. Accuracy of the use of kinematic models for prediction of avalanche characteristics need to be validated so that mitigation will be done correctly. Validation is done by doing a comparison between model predictions and the size of the data and statistical tests for the feasibility of prediction of each point of the GPS monitor. Validation is known that the predicted results at some GPS monitor point is not suitable for use. With the vector of the movement of materials, we know the direction and scalar, velocity and acceleration of material displacement. The movement of landslide materials at Ciloto Zone dominated north-west to south-easterly direction and speed to slow very slow (creep). Keywords: accuracy, characteristics, kinematic model, landslide.
Temporal Variation Analysis From Troposphere Delay Using GPS (Study: Bandung, Indonesia) Dhota Pradipta; Wedyanto Kuntjoro; Kosasih Prijatna
Indonesian Journal of Geospatial Vol 1 No 1 (2012)
Publisher : Indonesian Journal of Geospatial

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Abstract.Tropospheric delay is the amount of distortion caused by the deceleration of satellite's signal propagation due to the influence of troposphere. The value of this delay is certain effect of elevation angle that is called the slant delay. In the processing of GPS signals correction, the value of slant delay will be converted using a mapping function to the measured value of the zenith delay which became known as the Zenith Total Delya (ZTD). Zenith value is an accumulated value of the tropospheric delay along the signal's path at the zenith direction. The value of ZTD can be determined by GPS technique. In Geodesy, ZTD is a nuisance parameter, but for meteorology, it is a parameter of interest, which causes from variability of the atmospheric constituens. The section of ZTD, i.e. Zenith Wet Delay (ZWD), could be derived by substracting Zenith hydrostatic Delay (ZHD) component from ZTD. By surface temperature readings at the GPS receiver, the retrieved ZWD can then be transformed with additional uncertainty into an estimate of the Precipitable Water Vapor (PWV). The aim of this research is to study temporal behavior of PWV at ITB campus, as it is revealed from GPS measurements. According to the research that has been conducted, we obtained some results, i.e. The data quality and strategy which were used in processing could affect the result, In particular, we found that, within 20 minutes, maximum and minimum PWV values could reach 85.2 mmand 6.4 mm, respectively. It may indicate that the atmosphere above the studied are varies highly. Temporal condition in observation point that appears in result such as at 12.00 "“ 18.00 WIB often shows significant irregular anomalies of PWV that influenced local area observation. Keywords: GPS, PWV, temporal analysis, ZTD. 
Determination of ZNHD based on GPS Data, Radiosonde, and Numerical Weather Model Susilo Susilo; Dudy D. Wijaya; Wedyanto Kuntjoro; Joni Efendi
Indonesian Journal of Geospatial Vol 1 No 2 (2012)
Publisher : Indonesian Journal of Geospatial

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Abstract. Water vapor is a principal element in the thermodynamics of the atmosphere and plays an important role in clouds condensation, which eventually can affect the radiative energy balance. Water vapor cobservation is essential for monitoring global/regional scale of weather and climate changes. However, high variation of water vapor concentrations makes it difficult to observe accurately using the conventional meteorogical observation technique (radiosonde), which is limited in both space and time. Nowadays, accurate observation of water vapor can be accomplished by the Global Positioning System (GPS). In this research, we use 14 continuous GPS stations from Bakosurtanal to observe temporal characteristic of water vapor concentration over West Java region.Keywords: GPS, NCEP, radiosonde, topographic, ZNHD