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Welcome to the homepage of Micro-Laboratory of Atmospheric Research and Geomatics Engineering (Micro-LARGE)

 

The publication list is updated on September 2, 2016

 

[023]

Kumar, Sanjay*, Wu Chen, Zhizhao Liu, Shengyue Ji (2016), Effects of solar and geomagnetic activity on the occurrence of equatorial plasma bubbles over Hong Kong, Journal of Geophysical Research (Space Physics), 1 September 2016

[022]

Yu, Tao*, Chunliang Xia, Xiaomin Zuo, Cong Huang, Tian Mao, Libo Liu, Zhizhao Liu (2016), A comparison of mesospheric winds measured by Fabry Perot interferometer and Meteor Radar over Center China, Journal of Geophysical Research (Space Physics), accepted 1 September 2016

[021]

Yang, Zhe* and Zhizhao Liu (*) (2016), Investigating the Inconsistency of Ionospheric ROTI Indices Derived from GPS Modernized L2C and Legacy L2 P(Y) Signals at Low-Latitude Regions, GPS Solutions, accepted

[020]

Song, Aotian, Lin Lu (*), Zhizhao Liu, Man Sing Wong (2016), A Study of Incentive Policies for Building-Integrated Photovoltaic Technology in Hong Kong. Sustainability 8 (8): 769. doi:10.3390/su8080769. (2016 Impact Factor: 1.343)

[019]

Chen, Biyan*, Zhizhao Liu (*) (2016), Assessing the Performance of Troposphere Tomographic Modeling Using Multi-Source Water Vapor Data During Hong Kong’s Rainy Season from May to October 2013, Atmospheric Measurement Techniques (AMT), doi:10.5194/amt-2016-158.

[018]

Yang, Zhe*, Zhizhao Liu (*) (2016), Observational Study of Ionospheric Irregularities and GPS Scintillations Associated with the 2012 Tropical Cyclone Tembin Approaching Hong Kong, Journal of Geophysical Research - Space Physics

[017]

Zhang, Bochen, Xiaoli Ding, Wu Zhu, Chisheng Wang, Lei Zhang, and Zhizhao Liu. (2016), Mitigating Ionospheric Artifacts in Coseismic Interferogram Based on Offset Field Derived From ALOS-PALSAR Data, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, Vol. 9 (7): 3050–59. doi:10.1109/JSTARS.2016.2533441

[016]

Wong, Man Sing, Rui Zhu, Zhizhao Liu, Lin Lu, Chung Ho Lo, Zhaoqin Tang (2016), Estimation of Hong Kong’s solar energy potential using GIS and remote sensing technologies, Renewable Energy, Vol. 99, pp. 325–335, doi:10.1016/j.renene.2016.07.003

[015]

Zhao, Qile, Guangxing Wang (*), Zhizhao Liu (*), Zhigang Hu, Zhiqiang Dai, and Jingnan Liu (2016). Analysis of BeiDou Satellite Measurements with Code Multipath and Geometry-Free Ionosphere-Free Combinations. Sensors 16 (1): 123. doi:10.3390/s16010123. [GZL1] 

 

The following funding agencies are highly appreciated for their kind supports.

(1)

http://www.a-tech.hk/philips2012/images/PolyU-Logo.jpg

The Hong Kong Polytechnic University (PolyU)

(2)

National Scientific Foundation of China (NSFC)

(3)

Hong Kong Research Grants Council (RGC)

(4)

http://www.croucher.org.hk/wp-content/themes/Croucher/images/headers/CF_logo_en.png

The Croucher Foundation

裘槎基金會

(5)

Central Policy Unit

Central Policy Unit, The Government of the Hong Kong Special Administrative Region

(6)

Innovation and Technology Fund  Innovation and Technology Commission  The Government of the Hong Kong Special Adminstrative Region

Innovation and Technology Fund, Innovation and Technology Commission, The Government of the Hong Kong Special Administrative Region

 

We are very appreciative of the following agencies having provided helps and assistances for Dr. Liu’s research group:

(1)

Lands Department - The Government of the Hong Kong Special Administrative Region

The Lands Department, The Government of the Hong Kong Special Administrative Region

(2)

Hong Kong Observatory logo

The Hong Kong Observatory (HKO), The Government of the Hong Kong Special Administrative Region

(3)

The Cartography and Cadastre Bureau, The Government of the Macao Special Administrative Region

(4)

回首頁http://www.smg.gov.mo/www/ComImages/title3.gif

The Macao Meteorological and Geophysical Bureau (SMG), The Government of the Macao Special Administrative Region

(5)

Company logo

The First Ferry, Hong Kong

 

 

This research group has a great interest in the ionosphere and space weather, and space geodesy. Currently the primary research is to study the coupling relationship of solar wind-magnetosphere-ionosphere using high precision GPS-inferred ionospheric data. More specifically the work includes global especially low-latitude and mid-latitude ionospheric characteristics, ionospheric irregularities and structures, ionospheric scintillation, monitoring of ionosphere and space weather, ionospheric modeling, methodology of using GPS to measure the ionosphere, and solar flare effects on ionosphere.

 

The ultimate goal of this research group is to reveal the relationship between the change of ionosphere and space weather and the change of other geophysical signals, and the impact on human being activities.

 

 

[May 26, 2013] Recently, Dr. Liu made a presentation of a paper titled “A Comparison of GNSS-based Ionospheric Scintillation Observations in North and South Hong Kong” at the recent 2013 Pacific PNT held at Honolulu, Hawaii, USA during April 22-25, 2013. This paper was coauthored by Zhizhao Liu, Rui Xu, Yu Morton, Jisheng Xu, Wouter Pelgrum, Steve Taylor, Wu Chen and Xiaoli Ding.

DSC01430.JPG

 

 

[06] We are very pleased to announce that Dr. Liu is to receive the Excellent Paper Award from the 2013 4th Chinese Satellite Navigation Conference (CSNC 2013) in Wuhan, China.

 

In the recent 2013 China Satellite Navigation Conference (CSNC) held May 15-17 in Wuhan, Dr. George Zhizhao Liu from the Department of Land Surveying & Geo-Informatics (LSGI) received the Excellent Paper Award for his paper “The First PPP-based GPS Water Vapor Real-Time Monitoring System in Pearl-River-Delta Region, China” co-authored with Research Associate Dr. Min Li. This paper presents their research findings of developing the first atmospheric water vapor real-time monitoring system for the Pearl-River-Delta (PRD) region using the latest Global Positioning System (GPS) Precise Point Positioning (PPP) technique. Based on their technique, now the amount of water vapor in the atmosphere over the PRD region can be quickly and accurately computed from GPS satellite signals. Since April 2012, the PolyU researchers have been supplying their atmospheric water vapor data to the meteorological agencies around the PRD region to support their daily services and research, including Hong Kong Observatory, Macao Meteorological and Geophysical Bureau, Guangdong Meteorological Bureau and Shenzhen Meteorological Bureau.

 

This year is the first time for CSNC to have the Excellent Paper Award. Dr. Liu was one of the nine award recipients out of 629 paper submissions (success rate: 1.43%). This research work was supported by the General Research Fund (GRF) of Hong Kong Research Grants Council (RGC).

 

[03] We are very pleased to announce that our project is successfully funded by National Scientific Foundation of China (NSFC), RMB700,000 over 2013-2016.

[02] We are very pleased to announce that our project is successfully funded by Hong Kong’s Research Grants Council (RGC), HK$ 988,087 over 2013-2015.

[01] We are very pleased to announce that our project is successfully funded by Hong Kong’s Research Grants Council (RGC), HK$ 654,686 over 2013-2014.

 

 

Advanced Research Laboratories/Instruments/Resources/Tools:

[04] Establishing the First GNSS Receiver and Radiosonde Collocation Observation Station in Hong Kong

Photo1, Photo2

 

[03] The First Atmospheric Water Vapor Real-Time Monitoring System (WVRMS) for Pearl-River-Delta (PRD) Region, China

We are very proud that the MicroLARGE laboratory has established the First Atmospheric Water Vapor Real-Time Monitoring System (WVRMS) for Pearl-River-Delta (PRD) Region. This WVRMS is based on the latest GPS/GNSS technique – Precise Point Positioning (PPP), which enables the fast and accurate retrieval of water vapor from GPS/GNSS signals. We adopted the PANDA software developed at Wuhan University, China to process the GPS/GNSS data, with some modifications.

This WVRMS system started to officially provide water vapor data to Hong Kong Observatory (HKO) since 19 April 2012.

You can browse the PRD region’s Real-time atmospheric water vapor data by clicking here….

 

In the world, there are only a limited number similar systems in operation with similar PPP technologies:

(1)        Japan’s GEONET system using GIPSY since 2007

(2)        German Helmholtz Association Project "GPS Atmosphere Sounding" GASP using EPOS since 2000

(3)        …..

 

[02] Hong Kong’s 2nd GNSS Scintillation Monitoring (GSM) Station

This state-of-the-art GNSS Scintillation Monitoring Station was established on 13 August 2012.

One NovAtel OEMV receiver is deployed at a Sha Tin station in North of Hong Kong.

This GSM station is about 21.7 km from PolyU campus.

Photo1, Photo2

[01] Hong Kong’s First GNSS Scintillation Monitoring (GSM) Station

This state-of-the-art GNSS Scintillation Monitoring Station was established on 24 May 2012.

One Septentrio PolaRxS receiver is deployed at a coastal station in South of Hong Kong.

This GSM station is about 21.7 km from PolyU campus.

Photo1, Photo2, Photo3, Photo4

 

Research Interests:

·         Space Weather and Storm time effect observation and analysis using GPS/GNSS and other techniques

·         GPS/GNSS accuracy and reliability and ionospheric/space weather effects

·         Ionospheric modeling using Ground-based and Space-based GPS/GNSS network

·         Global Navigation Satellite Systems (GNSS)

·         Algorithm development and software development for GNSS

·         Remote sensing of atmosphere using GNSS

·         Precise absolute and relative positioning using GNSS

Journal Publications:

 

Some submitted manuscripts:

Xu, Ying, Shengyue Ji, Lei Ye, Duojie Weng, Zhizhao Liu, Wu Chen (2013), Experimental Study on the Performance of Chinese BeiDou System, submitted to GPS Solutions, submitted July 10, 2013.

Mansing Wong, Xiaomeng Jin, Zhizhao Liu (*), Janet Nichol (2013), Multi-sensor Study of Precipitable Water Vapor over Mainland China, to be submitted to Atmospheric Environment (Supported by B-Q28F, submitted August 2013)

Han, Joong-hee, Zhizhao Liu (*), Jay Hyoun Kwon, Investigating the Impact of Random and Systematic Errors on GPS Precise Point Positioning Ambiguity Resolution, Journal of Navigation, (in review, submitted 06 Feb. 2013, Supported by 1-ZV6L, A-PJ63, A-PJ78, and RGC project F-PP0F)

Mansing Wong, Xiaomeng Jin, Zhizhao Liu (*), Yuanling Zhou, Shirong Ye, Peng Jiang, and P.W. Chan, Estimation of Atmospheric Water Vapor using MTSAT Satellite Data, a Study in China (to be submitted, Supported by B-Q28F.)

Liu, Zhizhao (*), Weihua Luo, and Jisheng Xu, The GPS TEC Variations Observed in the Equatorial Ionosphere Anomaly Regions prior to Three Large Earthquakes. Advances in Space Research (submitted 1 April 2013, Supported by 1-ZV6L, A-PJ63, and B-Q28F.)

 

Published Papers:

 

 

[037]

Biyan Chen and Zhizhao Liu (*) (2014), Voxel-Optimized Regional Water Vapor Tomography and Comparison with Radiosonde and Numerical Weather Model, Journal of Geodesy, accepted (IF: 2.808)

[036]

Zhizhao Liu (*), Biyan Chen, Sai Tick Chan, Yunchang Cao, Yang Gao, Kefei Zhang, and Janet Nichol (2014), Analysis and modeling of water vapor and temperature changes in Hong Kong using a 40-year radiosonde record: 1973-2012. International Journal of Climatology, accepted (IF: 2.479)

[035]

Cai, Changsheng, Xiaomin Luo, Zhizhao Liu (*) and Qinqin Xiao (2014), Galileo Signal and Positioning Performance Analysis Based on Four IOV Satellites. Journal of Navigation, accepted (IF: 0.618, Relative ranking within Categories: Engineering, marine 5/14)

[034]

Zhongbin Li, Zhizhao Liu, and Wenzhong Shi (*) (2014), Semiautomatic Airport Runway Extraction Using a Line-Finder-Aided Level Set Evolution, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing (IEEE JSTARS), Accepted (2013 IF: 2.874) The source codes can be found here.

[033]

Xu, Rui, Zhizhao Liu (*), Wu Chen (2013), Improved FLL-assisted PLL with In-phase Pre-filtering to Mitigate Amplitude Scintillation Effects, GPS Solutions, Accepted.

[032]

Xia, Pengfei, Changsheng Cai (*), Zhizhao Liu (*) (2013), A troposphere tomography approach based on combined non-iterative and iterative reconstructions using GPS and COSMIC occultation data. Annales Geophysicae (submitted 31 March, 2013, Accepted, Supported by B-Q28F, IF: 1.518)

[032]

Liu, Zhizhao (*), Min Li, Weikun Zhong, Mansing Wong (2013), An Approach to Evaluate the Absolute Accuracy of WVR Water Vapor Measurements Inferred from Multiple Water Vapor Techniques. Journal of Geodynamics (accepted, Supported by B-Q28F, IF: 2.967)

[031]

Li, Zhongbin, Zhizhao Liu and Wenzhong Shi (2013), A Fast Level Set Algorithm for Building Roof Recognition from High Spatial Resolution Panchromatic Images. IEEE Geoscience and Remote Sensing Letters. (accepted, Supported by B-Q28F)

[030]

Luo, Weihua, Zhizhao Liu (*) and Min Li (2013), A Preliminary Evaluation of the Performance of Multiple Ionospheric Models in Low- and Mid-Latitude Regions of China in 2010-2011. GPS Solutions, DOI 10.1007/s10291-013-0330-z

[029]

Cai, Changsheng, Zhizhao Liu (*) and Xiaomin Luo (2013), Single-frequency Ionosphere-free Precise Point Positioning Using Combined GPS and GLONASS Observations. Journal of Navigation, 66, 417–434. doi:10.1017/S0373463313000039

[028]

Xu Rui*, Zhizhao Liu (*), Min Li, Yu Morton and Wu Chen (2013), An Analysis of Low-Latitude Ionospheric Scintillation and Its Effects on Precise Point Positioning. Journal of Global Positioning Systems, Vol. 11, No.1, 22-32

[027]

Liu, Zhizhao (*), Shengyue Ji*, Wu Chen, and Xiaoli Ding (2013), New Fast Precise Kinematic Surveying Method Using A Single Dual-Frequency GPS Receiver, Journal of Surveying Engineering, 139(1), 19-33

[026]

Cai, Changsheng, Zhizhao Liu (*), Pengfei Xia, Wujiao Dai (2013), Cycle-slip detection and repair for undifferenced GPS observations under high ionospheric activity, GPS Solutions, 17:247–260, DOI: 10.1007/s10291-012-0275-7 (ranked 2nd in the top five most downloaded papers in the journal with 339 downloads within 90 days of its online publication. To authors’ knowledge, this method so far has been implemented by researchers at Helmholtz Centre Potsdam GeoForschungsZentrum (GFZ) German Research Centre for Geosciences, Germany)

[025]

Liu, Zhizhao, Man Sing Wong, Janet Elizabeth Nichol, and P.W. Chan (2011), A multi-sensor study of water vapor from Radiosonde, MODIS and AERONET: a case study of Hong Kong, International Journal of Climatology, DOI: 10.1002/joc.3412 (SCI IF: 2.479)

[024]

Liu, Zhizhao (2011), A New Automated Cycle Slip Detection and Repair Method for a Single Dual-Frequency GPS Receiver, Journal of Geodesy, 85:171–183, DOI 10.1007/s00190-010-0426-y (ranked 3rd as one of the top five most downloaded papers in the journal with 308 downloads within 90 days of its online publication, in addition to the downloads directly from author’s personal website. This method so far has been implemented by researchers at ~10 research groups in UK, China and Canada Universities, including University of New Brunswick (Canada), University of Calgary (Canada), Imperial College London (UK), Wuhan University (China), Peking University (China), Beijing University of Aeronautics and Astronautics (China), Central South University (China), Hohai University (China).)

[023]

Liu, Zhizhao, Susan Skone and Yang Gao (2006). Assessment of Tomographic Modeling Performance Using GPS Data during October 2003 Ionospheric Storm, Radio Science, Vol. 41, RS1007, doi:10.1029/2004RS003236.

 

[022]

Liu, Zhizhao, Susan Skone and Yang Gao (2005). A study of TEC data precision inferred from GPS measurements, Earth Planets Space, Vol. 57, No. 11, pp. 999-1007.

 

[021]

Chen, Zhiyu, Yang Gao and Zhizhao Liu (2005). Evaluation of Solar Radio Bursts’ Effect on GPS Receiver Signal Tracking Within IGS Network, Radio Science, Vol. 40, RS3012, doi:10.1029/2004RS003066.

 

[020]

Liu, Zhizhao, Susan Skone, Yang Gao and Attila Komjathy (2004). Ionospheric Modeling Using GPS Data, GPS Solutions, Vol. 9, No. 1, doi: 10.1007/s10291-004-0129-z (invited).

 

[019]

Liu, Zhizhao and Yang Gao (2004). Development and Evaluation of a New 3D Ionospheric Modeling Method, NAVIGATION, Journal of The Institute of Navigation, Vol. 51, No. 4, pp. 311-329.

 

[018]

Liu, Zhizhao, Yang Gao and Kongzhe Chen (2003). Precise Ionospheric TEC Prediction for Precise Point Positioning Using a Single-Frequency GPS Receiver, Geomatics Research Australasia, No.80, June, 2004, pp. 73-87.

 

[017]

Liu, Zhizhao and Yang Gao (2003). Ionospheric TEC Predictions over A Local Area GPS Reference Network, GPS Solutions, Vol. 8, No. 1, pp. 23-29.

 

[016]

Liu, Zhizhao and Yang Gao (2003). Performance Analysis of a 3D Ionosphere Tomographic Model, Wuhan University Journal of Natural Sciences, Vol. 8, No. 2B, pp. 619-626.

 

[015]

Gao, Yang and Zhizhao Liu (2002). Precise Ionosphere Modeling Using Regional GPS Network Data, Journal of Global Positioning Systems, Vol. 1, No. 1, pp. 18-24.

 

[014]

Gao, Yang, Xiangqian Liao and Zhizhao Liu (2002). Ionosphere Modeling Using Carrier Smoothed Ionosphere Observations from a Regional GPS Network, Geomatica, Vol. 56, No. 2, pp.97-106.

 

[013]

Gao, Yang, Zhe Liu and Zhizhao Liu (2002). Internet-Based Real-Time Kinematic Positioning, GPS Solutions, Vol.5, No.3, pp. 61-69.

 

[012]

Liu, Zhizhao, Jingnan Liu and Zhenghang Li (2000). The Application of GPS Technology to Meteorology, Bulletin of Surveying and Mapping, No. 2. (Chinese)

 

[011]

Zhang, Quande, Zhizhao Liu and Zhanyi Sun (2000). Establishment of High Precision Geodetic Network in South China Sea, Bulletin of Surveying and Mapping, No. 8. (Chinese)

 

[010]

Liu, Zhizhao, Zhenghang Li and Jingnan Liu (1998). The Improvement on Temporal Resolution of Deformation Analysis on Baseline Using Continuously Observed GPS Data, Journal of Wuhan Technical University of Surveying and Mapping, Vol.23, pp.73-75. (Chinese)

 

[009]

Liu, Zhizhao, Zhenghang Li and Shaoquan Xu (1998). The Analysis of the Digital Characteristics of Multi-session Solutions of GPS Short Baselines, Journal of Wuhan Technical University of Surveying and Mapping, Vol.23, pp. 69-72. (Chinese)

 

[008]

Li, Zhenghang, Zhizhao Liu and Xiaohong Zhang (1998). The Effective Method to Improve the Precision of Monitoring Dam Deformation with GPS, Journal of Wuhan Technical University of Surveying and Mapping, Vol.23, pp. 15-19. (Chinese)

 

[007]

Li, Zhenghang, Zemin Wang, Zhizhao Liu and Jianjun Zhang (1998). Performing Submillimeter Level Positioning on Short Baselines with GPS, Journal of Wuhan Technical University of Surveying and Mapping, Vol.23, pp. 9-14. (Chinese)

 

[006]

Liu, Zhizhao and Zhenghang Li (1998). Precisely Positioning on Short Baseline using GPS Technology, Journal of Southern Institute of Metallurgy, Vol. 19, No.3, pp. 161-165. (Chinese)

 

[005]

Liu, Zhizhao (1997). The Monitoring of Movement of the Antarctic Continent using GPS, WTUSM Bulletin of Science and Technology, No.3, pp. 19-21. (Chinese)

 

[004]

Liu, Zhizhao and Zhenghang Li (1997). Influence of Eccentricity of GPS Antenna on the Computation of Baseline, WTUSM Bulletin of Science and Technology, No.2, pp. 10-13. (Chinese)

 

[003]

Liu, Zhizhao and Zhenghang Li (1997). Discussion on the Selection of Coefficient of LC Observation, Journal of Southern Institute of Metallurgy, Vol.18, No.1, pp. 6-10. (Chinese)

 

[002]

Li, Zhenghang, Zhizhao Liu and Zemin Wang (1996). Study on Monitoring Dam Deformation with GPS Positioning, Journal of Wuhan University of Hydraulic and Electric Engineering, Vol.29, No.6, pp. 26-29. (Chinese)

 

[001]

Li, Zhenghang, Zemin Wang, Zhizhao Liu and Jianjun Zhang (1996). Research on Precisely Positioning Technique on Short Baseline using GPS, Science and Technology Information of Surveying and Mapping, No.2, pp. 31-36. (Chinese)

Figure 1. One of the papers was ranked 2nd in the top five most downloaded papers in the journal of “GPS Solutions” with 339 downloads within 90 days of its online publication. “GPS Solutions” is regarded as the most authoritative journal in the GPS/GNSS community. To authors’ knowledge, this method so far has been implemented by researchers at Helmholtz Centre Potsdam GeoForschungsZentrum (GFZ) German Research Centre for Geosciences, Germany.

 

Figure 2. One of the papers was ranked 3rd in the top five most downloaded papers in the journal of “Journal of Geodesy” with 308 downloads within 90 days of its online publication, in addition to the downloads directly from author’s personal website. “Journal of Geodesy” is regarded as the most authoritative journal in the Geodesy community. To authors’ knowledge, this method so far has been implemented by researchers at ~10 research groups in UK, China and Canada Universities, including University of New Brunswick (Canada), University of Calgary (Canada), Imperial College London (UK), Wuhan University (China), Peking University (China), Beijing University of Aeronautics and Astronautics (China), Central South University (China), Hohai University (China).

 

 

 

 


 [GZL1]