Kwo-Hwa Chen

National Taipei University · Real Estate and Built Environment

Construction of a coseismic displacement grid model (hereafter referred to as the grid model) is a critical strategy for maintaining the precision of the semi-kinematic reference frame. However, no unequivocal criteria have yet been suggested for the timing of grid model construction. To clarify this timing, the observations of continuous global na...

Abstract Surface displacements associated with earthquake-cycle deformation of active faults significantly influence the accuracy of geodetic datum and reference frames, especially for the Taiwan area with high plate convergence and deformation rates. Following the current architecture of the semi-kinematic reference frame in Taiwan, which does not...

A semi-dynamic geodetic datum, composed of a static geodetic datum and a surface deformation model, is proposed in this study to maintain the accuracy of geodetic datum in Taiwan. A concept to construct the surface deformation model is also suggested to accommodate the characteristics of temporal variation of the velocity field and coseismic displa...

Global sea level rise due to an increasingly warmer climate has begun to induce hazards, adversely affecting the lives and properties of people residing in low-lying coastal regions and islands. Therefore, it is important to monitor and understand variations in coastal sea level covering offshore regions. Signal-to-noise ratio (SNR) data of Global...

Water vapor plays an important role in weather prediction. Thus, it would be helpful to use precipitable water vapor (PWV) data from Global Positioning System (GPS) signals to understand weather phenomena. Approximately 100 ground GPS stations that cooperate with approximately 500 ground weather stations were used in this study. The relationship be...

To accommodate the effects of crustal deformation in the current national static geodetic datum (Taiwan Geodetic Datum 1997 (TWD97)) in SW Taiwan, 221 campaign-mode global positioning system (GPS) stations from 2002 to 2010 were used in this study to generate a surface horizontal velocity model for establishing a semi-dynamic datum in SW Taiwan. An...

We adopted 106 campaign-mode GPS observations and 310 precise leveling measurements between 2002 and 2010 to understand the present-day crustal deformation in mudstone area and to estimate the earthquake potential of the Hsiaokangshan (HKSF) and the Chishan faults (CHNF) in southwest Taiwan. Horizontal velocities east of the CHNF are ~ 66 mm/yr, 27...

Despite the pervasive use of the global positioning system (GPS) as a positioning technology for its high efficiency and accuracy, several factors reduce its performance. This study examines to which extent the frequency offset and the frequency stability of the internal quartz oscillator or of an externally supplied rubidium oscillator have an inf...

To characterize the present-day vertical displacement field in the active Taiwan orogenic belt, 1843 precise leveling and 199 continuous GPS measurements from 2000 to 2008 are collected and analyzed in this study. Vertical velocities derived from the leveling data are placed in a reference frame of the Chinese continental margin using continuous GP...

We have developed the most precise vertical displacement rate field of Taiwan Island to date from four sets of precise geodetic levelling data between 2000 and 2008. More than 4000 km of levelling lines between solidly constructed benchmarks were repeatedly surveyed by 1st-order levelling. Strict specifications for field work procedures and compreh...

The next decade promises drastic improvements to global navigation satellite systems. The USA is modernizing GPS, Russia is refreshing GLONASS, Europe is moving ahead with its own Galileo system, and The People's Republic of China is expanding its Beidou-1 system from a regional navigation system to a full constellation global navigation satellite...

Mt. Jade (or "Yushan" in Chinese) is the highest peak in northeast Asia. The topography is very rugged and complicated. Such terrain makes it difficult to obtain the correct results for terrain corrections (TCs). This paper developed an improved approach, named cone-section method, to compute the TCs of the Mt. Jade area using a high-resolution dig...

Plum rains and typhoons are important weather systems in the Taiwan region. They can cause huge economic losses, but they are also considered as important water resources as they strike Taiwan annually and fill the reservoirs around the island. There are many meteorological sensors available for investigating the characteristics of weather and clim...

1] An airborne gravity survey was conducted over Taiwan using a LaCoste and Romberg (LCR) System II air-sea gravimeter with gravity and global positioning system (GPS) data sampled at 1 Hz. The aircraft trajectories were determined using a GPS network kinematic adjustment relative to eight GPS tracking stations. Long-wavelength errors in position a...

The island of Taiwan is located in an active tectonic zone on the boundary of the Eurasian and Philippine Sea plates. Due to the continuous mountain building process in association with the collision of the two plates, it is very important for Taiwan to periodically re-survey the island so as to maintain the intrinsic accuracy requirement of its ve...