Welcome
to the homepage of Micro-Laboratory of Atmospheric Research and Geomatics
Engineering (Micro-LARGE)
Recently updated (This
page was last updated on 11 Nov 2024)
[11 November 2024] At the end of September and
beginning of October 2024, a number of drone shows were cancelled and stirred a
lot of discussions among the public. Why were the drone shows cancelled? Why
could the drone shows in Shenzhen continued as planned but not in Hong Kong?
The culprit is the ionosphere scintillation, which significantly degrades the
GNSS real-time-kinematic (RTK) positioning performance from a few centimeters
to dozens of centimeters or even meters. On this topic, a number of articles
have been published by Prof. George Zhizhao Liu, jointly with partners Prof.
SHUN Chi-ming岑智明教授, former Director of the Hong Kong Observatory and Adjunct Professor at the
HKUST; Mr. Sr Leung Shou Chun 梁守肫測量師, former Chairman of the Hong Kong Institute
of Surveyors; and Ms. Fiona Chow, journalist of the South China Morning Post.
The articles can be found here: article
1, article
2, article
3, article
4, article
5, and article
6.
[11 November 2024] I am very pleased to share
with you that Jiafei Xu, who just completed his PhD oral examination on 4th
October 2024, is awarded the prestigious “PolyU Distinguished Postdoctoral
Fellowship Scheme”. Jiafei completed his PhD program in Prof. Liu’s Micro-LARGE
Lab within a period of 4 years and 1 month. During this period, he published 17 top-tier SCI
papers and several conference papers, including 15 papers in Q1 journals and 2
papers in Q2 journals. The details are:
·
7 papers published in IEEE Transactions on Geoscience and Remote Sensing,
lF: 7.5;
· 3 papers published in International Journal of
Applied Earth Observation and Geoinformation, IF: 7.6;
· 2 papers published in Geophysical Research
Letters, IF: 4.6;
·
5 papers published in other journals.
Congratulations to Jiafei!
The photo can be found here.
[11 November 2024] On the 8th
November 2024, Prof. George Zhizhao Liu was invited to give a “conference
invited talk” titled “Assimilating AMSR2 PWV Retrievals to Improve the WRF
Forecasting Performance of Warm-Sector Heavy Rainfall” at the 6th
China Mesoscale Meteorology Forum (第六届全国中尺度气象学论坛), hosted by the Sun
Yat-Sen University (Zhuhai), 7-10 November 2024. In addition, he was also
invited to give another talk titled “Enhanced
Atmospheric River (AR) Identification Algorithm and AR Catalogue of West Coast
of North America” at the
Session “Satellite Observation” on the 9th November 2024. He also
gave a 3rd talk titled “利用垂直积分水汽输送跟踪强热带气旋: 概念验证和初步可行性研究” (authors: Dr. Ruping Mo, Dr. George Zhizhao Liu) at the Session “Satellite Observation” on the 9th
November 2024. This is the first time for Prof. Liu to give three talks in one
single conference. Group photo can be found here.
[11 November 2024] On the 4th
November 2024, Prof. George Zhizhao Liu was invited to give a talk titled
“Forecasting Hong Kong Historic ‘7-8 September 2023’ Rainfall Event with
Different Schemes of GNSS and Satellite Microwave Water Vapor Data
Assimilation” at the 2024 Data Assimilation Technique Workshop (2024年资料同化技术交流会) at Shenzhen, which was organized by the
“Guangdong–Hong Kong–Macao Greater Bay Area Weather Research Center for
Monitoring Warning and Forecasting(粤港澳大湾区气象监测预警预报中心)”.
[11 November 2024] On the 28th October 2024, Prof. George
Zhizhao Liu was appointed as the Chief Scientist of the Meteorological
Observation Center, China Meteorological Administration (CMA). The photo can be
found here.
The Chinese Wechat article can be found here.
[11 November 2024] On the 27th October 2024, Prof. George
Zhizhao Liu gave an opening speech at the 8th International Graduate Workshop
on Geo-Informatics (IGWG) workshop-2024 at the Peking University. The
International Graduate Workshop on Geo-Informatics (IGWG) workshop is jointly
organized by the Peking University, Wuhan University, and the Hong Kong
Polytechnic University and hosted by the universities in turn. The 9th
IGWG workshop will be hosted at Hong Kong by the Hong Kong Polytechnic
University. The speech can be found here.
[28 August 2024] On 14 August 2024, Prof. George Zhizhao Liu completed
his two-month sabbatical leave at Prof. Roland Stull’s Weather Forecast
Research Team, Department of Earth, Ocean and Atmospheric Sciences, The
University of British Columbia (UBC), Vancouver, Canada. Photo with Prof. Stull
can be found here.
[28 August 2024] On 25 July 2024, Prof. George Zhizhao Liu was selected
an Outstanding Editor of the “Satellite Navigation”, a journal with an Impact Factor of 9.0 published by the Springer. The certificate
can be found here.
[9 April 2024] Prof. George Zhizhao Liu wrote a Chinese article to
celebrate the 70th birthday of Prof. Hui Lin, his remarkable
achievements in his career, and significant contributions to a wide community.
The article can be found here.
[9 April 2024] Prof. Hui Lin and Prof. George Zhizhao Liu initiated the
“Siben Forum(思本論壇)” and the first Siben Forum was successfully
organized at Jiangxi Normal University, Nanchang, Jiangxi, January 5-7, 2024.
The Chinese news can be found here.
[9 April 2024] Prof. George Zhizhao Liu is invited by the 台灣地球觀測學會(Taiwan Group of Earth Observation, TGEO) to attend
the International Conference on Earth Observations and Societal Impacts
(ICEO&SI) / Symposium of the International Association of Geo-informatics,
IAG'i) (https://2024-iceo-si.weebly.com/),
to be held at Taiwan Central University (台灣中央大學) June 28 to July 2, 2024. The title of his
talk at the ICEO&SI/IAG’i will be determined later.
[9 April
2024] Prof. George Zhizhao Liu will convene the
Atmospheric Sciences (AS) Session AS18 “Assimilation of Space- and Ground-based
Water Vapor Observations for Weather Forecasting and GNSS Applications” from
2:00 PM - 3:30 PM on 25 June 2024 at the Meeting Room: InterContinental at the
2024 AOGS Annual Meeting, to be held 23 to 28 June 2024 at the Alpensia and
Yong Pyong Ski Resorts, In Pyeongchang, Gangwondo (Home to 2018 Winter
Olympics), South Korea. The title of his talk at AOGS is: “Assimilating FY-4A
PWV Retrievals to Improve the WRF Forecasting Performance of Typhoon Haikui”.
Please note that K-ETA is temporarily waived for visitors from many
regions/countries.
The Co-Conveners of
the AS18 Session include: Dr Jonathan Jones (Met Office, United Kingdom), Prof
Jens Wickert (GFZ German Research Centre for Geosciences and Technical
University of Berlin, Germany), Prof Shu-Chih Yang (National Central
University, Taiwan), and Prof Kefei Zhang (China University of Mining and
Technology, China).
[9 April
2024] Prof. George Zhizhao Liu has been appointed as
a Visiting Professor by the Department of Earth, Ocean and Atmospheric Sciences
(https://www.eoas.ubc.ca/), The University of British Columbia
(https://www.ubc.ca/),
Vancouver, BC Canada. He will visit UBC
during 15 June 2024 to 14 August 2024.
[9 April 2024] Prof. George
Zhizhao Liu was invited to give a talk at the 2024 年導航衛星氣象觀測技術研討會 at Guangzhou 10-12
April 2024 organized by 中國氣象局氣象探測中心、廣東省氣象局、廣西壯族自治區氣象局。The title of his talk
is: Assimilating Microwave Satellite's PWV data to improve the rainfall
forecasting performance for the 2023 Typhoon Haikui-induced heavy rainfall.
[9 April 2024] Prof. George
Zhizhao Liu was invited to give a talk at the 2024（第四屆）民航空中交通管理科學技術交流會 at Beijing 10-12
April 2024 organized by 中國航空學會航空電子與空中交通管理分會、空地一體新航行系統技術全國重點實驗室。The title of his talk
is: 空間天氣對飛行運行的影響以及對空中交通管理的決策建議。
[9 April 2024] Prof. George
Zhizhao Liu was invited to give a talk at the 大飛機氣象前沿技術及應用研討會 at Shanghai 27-29
March 2024 organized by 中國氣象服務協會、中國民用航空局空中交通管理局航空氣象中心、《氣象科技進展》編輯部、and 中國商飛民用飛機試飛中心。The title of his talk
is: 基於同化微波衛星PWV 數據提高2023 年颱風“海葵”強降水預報性能。
[17 Aug 2023] Prof. George Zhizhao Liu’s list of
journal papers is published here. Prof. Liu’s Lab has published 111
journal papers so far.
[08 Aug 2023] Prof. George Zhizhao Liu is invited to
give an oral presentation
at the 5th National Symposium of the Mesoscale Meteorology held in
Yinchuan, Ningxia, China, 9-12 August 2023. Prof. Liu’s presentation title is:
Assimilating OLCI and MODIS NIR calibrated Precipitable Water Vapor (PWV) to
improve weather forecasting performance. This is Prof. Liu’s 2nd
time to attend “atmospheric science/meteorology” related session in a national
conference. This is also the 4th time for Prof. Liu’s to attend
“atmospheric science/meteorology” related session in national/international
conferences.
[08 Aug 2023] Prof. George Zhizhao Liu’s Lab did two
presentations at the 20th Annual Meeting of the Asia Oceania Geosciences
Society (AOGS) held in Singapore 30 July to 04 August 2023. PhD students
Yangzhao Gong and Jiafei Xu did their oral presentations in the Atmospheric
Science session (AS06): Assimilation of Space- and Ground-based Water Vapor
Observations for Weather Forecasting and GNSS Applications. This is Prof. Liu’s
2nd time to attend “atmospheric science/meteorology” related session
in an international conference.
[08 Aug 2023] Prof. George Zhizhao Liu did two oral
presentations at the 28th IUGG Assembly held in Berlin, Germany,
11-20 July 2023. Prof. Liu’s both presentations are on Atmospheric Science.
This is Prof. Liu’s 1st time to attend “atmospheric
science/meteorology” related session in an international conference.
（photo credit: Dr.
Jungang Wang, GFZ）
[08 Aug 2023] Prof. George Zhizhao Liu did one
invited oral presentation at the “2023
CPGPS Summit” held in Wuhan, China, 28-29 June 2023.
[08 Aug 2023] Prof. George Zhizhao Liu did one oral
presentation at the 5th Congress of China Geodesy and
Geophysics (CCGG) held in Wuhan, China, 21-23 April 2023. Prof. Liu’s
presentation is on Atmospheric Science with a title “Assimilating Sentinel-3
All-sky PWV Retrievals to Improve the WRF Forecasting Performance over the
South China”. This is Prof. Liu’s 1st time to attend “atmospheric
science/meteorology” related session in a national conference.
[02 Feb 2023] Croucher
Summer Course 2023 GPS/Beidou/GNSS
Satellite Positioning and Navigation and Earth Observation
Hong Kong Polytechnic UniversityHong Kong, P. R. China
28 May (Sunday) to 3 June (Saturday), 2023
Click here to registration online on the Google form before it
is full.
[30 January 2023] Dr. Shiwei Liu
successfully completed his PhD oral exam in November 2022 and was recently
awarded PhD degree by the Graduate School of Hong Kong PolyU.
[30 January 2023] Dr. Jie He
successfully completed her PhD oral exam in 2021 and was awarded the “Faculty
Award for Outstanding PhD Thesis” by Faculty of Construction and Environment
(FCE), Hong Kong PolyU in 2022.
[30 January 2023] Dr. Liu’s
General Research Fund (GRF) project was successfully funded by the Hong Kong
Research Grants Council (RGC). The result was announced on June 30, 2022. This was the No. 9 GRF project received
by Dr. Liu since he joined PolyU in 2009.
[30 January 2023] Dr. Liu’s rank of
successful General Research Fund (GRF) applications funded by the Hong Kong
Research Grants Council (RGC). The GRF is the most widely research grant and
every year almost all the research active academic staff across 8 public
universities in Hong Kong apply for the GRF projects. As of today, Dr. Liu’s
GRF success rank among ALL the 5795 funded academic staff (plus some
unfunded academic staff) in Hong Kong during the period 2006-2022 is given
below (from unofficial sources):
Rank=231, # of
Projects= 9, total_dollars=$ 7053500, average=$ 783722.22. mean # of projects
received by ALL the 5795 funded academic staff in
Hong Kong during the period 2006-2022 = 3.01 per funded academic staff. Dr. Liu’s # of funded GRF project is 5.99
higher than the mean value 3.01 across Hong Kong’s 8 public universities.
Rank of
Dr. Liu, Zhizhao in Hong Kong is: 231/5795=3.99%
As of today, Dr. Liu’s GRF
success rank among ALL the 923 funded academic staff (plus some
unfunded academic staff) in Hong Kong Polytechnic University (PolyU) during the
period 2006-2022 is given below:
Rank=25, # of
Projects= 9, total_dollars=$ 7053500, average=$ 783722.22. mean # of projects
received by ALL the 923 funded academic staff in PolyU during
the period 2006-2022 = 2.85 per academic staff. Dr. Liu’s
# of funded GRF project is 6.15 higher than the mean value 2.85 across Hong
Kong PolyU.
Rank of
Dr. Liu, Zhizhao in Hong Kong PolyU is: 25/923=2.71%
[31
March 2021] Here are the impact factors of a list of journals where we often
publish papers. Click here.
We will regularly update this file. Please visit the website regularly to check
up the update.
[30
March 2021] The Micro-LARGE Lab is very pleased to announce that the Gail
(Jia)’s paper titled “Water Vapor Retrieval
from MERSI NIR Channels of Fengyun-3B Satellite Using Ground-based GPS Data” has recently been
accepted by Remote
Sensing of Environment, which has an Impact Factor of 9.085 as of
March 2021. This is Micro-LARGE Lab’s first time to publish at Remote Sensing
of Environment. Also it is so far the paper of the highest Impact Factor at the
Micro-LARGE’s Lab. Congratulations to Gail!
[30
March 2021] The Micro-LARGE Lab is very pleased to announce that the following
papers have been published/accepted recently. Congratulations to all the
contributors: Shiwei and Jia!
|
Yu, Shiwei*, Zhizhao Liu (✉️) (2021), The Ionospheric Condition and GPS
Positioning Performance during the 2013 Tropical Cyclone Usagi Event in the
Hong Kong Region, Earth Planets Space, 73, 66. https://doi.org/10.1186/s40623-021-01388-2. |
|
He, Jia*, Zhizhao Liu (✉️) (2020), Water Vapor Retrieval from MERSI NIR
Channels of Fengyun-3B Satellite Using Ground-based GPS Data, Remote Sensing of Environment,
accepted. |
|
Yu, Shiwei*, Zhizhao Liu (✉️) (2020), Tropical cyclone-induced periodical
positioning disturbances during the Hato (1713) in the Hong Kong region, GPS
Solutions, accepted. |
|
He, Jia*, Zhizhao Liu (✉️) (2020), Applying the North Hemisphere
Developed New Water Vapor Retrieval Algorithm to the South Hemisphere, IEEE Transactions on Geoscience and
Remote Sensing (TGRS), accepted. |
|
Yu, Shiwei*, Zhizhao Liu (✉️) (2020), Temporal and Spatial Impact of the
Precipitable Water Vapor on the GPS Relative Positioning during the Hato
(2017) in Hong Kong and Taiwan Regions, Earth and Space Science, IF: 2.31, accepted 31 Jan 2021. |
[24
August 2020] The Micro-LARGE Lab is currently recruiting one PhD student to
work on GNSS Precise Point Positioning (PPP). Full scholarship is available.
Please contact Dr. Liu @ lszzliu@polyu.edu.hk
if you are interest. This scholarship is supported by Dr. Liu’s recent Hong
Kong RGC GRF research projects fund.
[24
August 2020] 28 August 2020, Dr. Liu will be invited by the Department to share
his RGC GRF project application experience with his colleagues, particularly
the young colleagues.
[24
August 2020] New PhD student Mr. Jiafei Xu has arrived at Hong Kong and he will
register in September for his PhD program at Micro-LARGE group.
[24 August 2020] We are
very pleased to announce that the following papers have been published or
accepted recently.
1.
Gong, Yangzhao*, Zhizhao Liu () (2020), Evaluating the Accuracy of Jason-3 Water Vapor Product
Using PWV Data from Global Radiosonde and GNSS Stations, IEEE Transactions
on Geoscience and Remote Sensing (TGRS), accepted. IF: 5.630 (PolyU Faculty
and Department A-journal)
2.
He, Jia*, Zhizhao Liu () (2020), Refining MODIS NIR Atmospheric Water Vapor Retrieval
Algorithm Using GPS-derived Water Vapor Data. IEEE Transactions on Geoscience and Remote Sensing (TGRS), accepted
August 2020, IF: 5.630 (PolyU Faculty and Department A-journal)
3.
Li, Guozhu, Baiqi Ning,
Yuichi Otsuka, Mangalathayil Ali Abdu, Prayitno Abadi, Zhizhao Liu,
Luca Spogli, and Weixing Wan (2020), Challenges to equatorial plasma bubble and
ionospheric scintillation short-term forecasting and future aspects in East and
Southeast Asia, Surveys in Geophysics, accepted. IF: 5.544 (PolyU Faculty and Department A-journal)
4.
Zhu, Mingchen*, Zhizhao Liu (), Wusheng Hu (2020),
Observing Water Vapor Variability during Three Super Typhoon Events in Hong
Kong Based on GPS Water Vapor Tomographic Modeling Technique, Journal of
Geophysical Research: Atmospheres, IF: 3.63, accepted 19 June 2020.
5.
He, Jia*, Zhizhao Liu () (2020), Water Vapor
Retrieval From MODIS NIR Channels Using Ground-Based GPS Data. IEEE Transactions on Geoscience and Remote
Sensing (TGRS), 58 (5): 3726–37, 12 pages,
https://doi.org/10.1109/TGRS.2019.2962057, IF:
5.630 (PolyU Faculty and Department
A-journal)
[24
August 2020] Dr. Liu (Team Leader) and colleagues are very proud to receiver
the “Dean’s Award for Outstanding Achievement in Services (Team award)”. This
is the single winning team in the Faculty of FCE in this category in 2020. As a
matter of fact, the Faculty of FCE doesn’t award this “Service Award” every
year as the selection criteria of “Service Award” is high.
[24
August 2020] Same as last year, Dr. Liu successfully secured a research fund
from the Hong Kong RGC (Research Grants Council) General Research Fund (GRF)
upon the announcement of the outcome on 30 June 2020. The success rate of Hong
Kong’s RGC GRF research project applications is about 35%, which is about 10%
higher of the US NSF 25%. Basically all the academic staff at the Hong Kong
universities attach importance to the RGC GRF application, as the success rate
is widely regarded an indicator to measure the research excellence. Over the
past 11 years, Dr. Liu successfully secured 7 RGC GRF projects, with a success
rate of 63.6%.
[25
May 2020] One Year-3 student visited my office in the afternoon of 25 May 2020
and discussed a topic for her BSc Final Year Project.
[25
May 2020] The presentation of BSc Final Year Project was completed in this
morning. Congratulations to Patrick.
[25
May 2020] We are glad to announce that Dr. George Liu’s last year application
for promotion to full professor has been approved by the Department, Faculty,
and University. Thank you all those who have contributed and supported to the
Micro-LARGE group. We pledge to work harder to promote research excellence in
the future.
[Sept.
2, 2016] We are pleased to see that two co-authored papers have been accepted
by the Journal of Geophysical Research -
Space Physics, on the same day September 01, 2016. One paper’s lead author
is Dr. Tao YU, a professor at the China University of Geoscience (Wuhan) and a
Research Associate at PolyU. Another paper’s lead author is Dr. Sanjay Kumar, a
Research Associate of PolyU. Congratulations to Dr. YU and Dr. Kumar! Click the
Research for more details.
[Sept.
2, 2016] We are pleased to announce that Jenny Yang’s paper has been accepted
the GPS Solutions, on 28 August
2016. Congratulations to Jenny! Click the Research for
more details.
[Aug.
29, 2016] Dr. Liu’s Research Proposal was successfully funded by the General
Research Fund (GRF) Scheme of Research Grants Council (RGC), the Hong Kong SAR
Government. The RGC’s fund application is very competitive every year and only
the real top quality proposals are selected to be funded. The funding size to
Dr. Liu’s project is HK$844,559,
which represents the
largest project in terms of funding size in the Faculty of Construction
and Environment, PolyU in 2016. PhD students are to be recruited and
applications are welcome!
[Aug.
29, 2016] Eventually our website has been updated by myself. In the past one to
two years, a number of students promised to update/redesign my website but it
was never realized.
[Dec.
03, 2014] We are pleased to share with you that the following papers have been
accepted for publication at top journals.
Xu,
Rui, Zhizhao Liu, and Wu Chen. 2014. “Improved FLL-Assisted PLL with in-Phase
Pre-Filtering to Mitigate Amplitude Scintillation Effects.” GPS Solutions,
June, 1–14. doi:10.1007/s10291-014-0385-5.
Wong,
Man Sing, Xiaomeng Jin, Zhizhao Liu, Janet Nichol, and P. W. Chan. 2014.
“Multi-Sensors Study of Precipitable Water Vapour over Mainland China.”
International Journal of Climatology, November, n/a – n/a.
doi:10.1002/joc.4199.
Weng,
Duojie, Shengyue Ji, Wu Chen, and Zhizhao Liu. 2014. “Assessment and Mitigation
of Ionospheric Disturbance Effects on GPS Accuracy and Integrity.” The Journal
of Navigation 67 (03): 371–84. doi:10.1017/S0373463314000046.
Luo,
Weihua, Zhizhao Liu, and Min Li. 2014. “A Preliminary Evaluation of the
Performance of Multiple Ionospheric Models in Low- and Mid-Latitude Regions of
China in 2010–2011.” GPS Solutions 18 (2): 297–308.
doi:10.1007/s10291-013-0330-z.
Liu,
Zhizhao, Biyan Chen, Sai T. Chan, Yunchang Cao, Yang Gao, Kefei Zhang, and
Janet Nichol. 2014. “Analysis and Modelling of Water Vapour and Temperature
Changes in Hong Kong Using a 40-Year Radiosonde Record: 1973-2012.”
International Journal of Climatology, April, n/a – n/a. doi:10.1002/joc.4001.
Li,
Zhongbin, 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 Early Access
Online. doi:10.1109/JSTARS.2014.2298332.
[March
21, 2014] We are pleased to share with you that the following papers have been
accepted for publication at top journals.
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)
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)
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)
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)
[November 29, 2013]
I am very pleased to Dr. Liu’s application for the Croucher
Summer Course “GPS/Beidou/GNSS
Satellite Positioning and Navigation and Earth Observation” has
been successfully granted by The
Croucher Foundation Limited, Hong Kong, 5 years, 2014-2018. The generous support from The Croucher Foundation Limited is HK$1,708,500, which will be paid in
three equal installments of HK$569,500. Thank you The Croucher Foundation Limited!
[November 29, 2013]
I am very pleased to announce that TWO (2) Public Policy Research
(PPR) projects are funded. Dr. Liu is a Co-Investigator
in these two projects. Thank you Central Policy Unit, Government of Hong Kong Special Administrative
Region!
The project information is:
2013, Co-Principal
Investigator (Co-PI), “A Remote Sensing Study of Solar Energy Supply
in Cloud-prone Areas of Hong Kong”, Public
Policy Research Funding Scheme (2013-2014), Central Policy Unit, Government of
Hong Kong Special Administrative Region (HKSAR), 12 months,
HK$359,869.50. [PI: Dr. Charles Man
Sing Wong, Assistant Professor, Department of Land Surveying &
Geo-Informatics, The Hong Kong Polytechnic University]
2013, Co-Principal Investigator (Co-PI),
“Study on
the development potential and energy incentives of rooftop solar photovoltaic
applications in Hong Kong”, Public
Policy Research Funding Scheme (2013-2014), Central Policy Unit, Government of
Hong Kong Special Administrative Region (HKSAR), 12 months, HK$424,120.
[PI: Dr. Vivien Lu, Associate Professor,
Department of Building Services Engineering, The Hong Kong Polytechnic
University]
[November
20, 2013] Dr. George Liu was honored as a Guest Professor of the GNSS Research
Center, Wuhan University.
[October
25, 2013] Dr. George Liu’s proposal
was funded by the University.
[October
08, 2013] Dr. George Liu joined the HKIES society.
[September
22, 2013] We are very pleased to announce that Dr. George Zhizhao Liu received
the “Best Researcher of the Year 2013” from the Department of LSGI. This news
was announced on 19 September 2013 by the Departmental Research Committee.
[August
18, 2013] We are very pleased to announce that Dr. George Zhizhao Liu received
the 2013 Dean’s Award. Dr. Liu joined other 9 colleagues in the Faculty of
Construction and Environment (FCE) to receive this prestigious award. Also he
is the only recipient from the Department of LSGI. As the recipient of the
Dean’s Award,
Dr.
Liu will be honoured at the Faculty Congregation and Prize Presentation
Ceremony to be held November 2013 with a cash prize of HK$15,000. In addition,
he will be awarded a research grant of HK$200,000 to support his future
research!
More
details can be found at the Faculty’s eBulletin:
http://www.polyu.edu.hk/fce/eBulletin/public/issue33/#03
[July 08, 2013] We
are very delighted to announce the annual Hong Kong Research Grants Council
(RGC)’s General Research Fund (GRF) project application submitted by Dr. Liu
last year is successfully funded!
This news was
officially announced 28 June 2013. Dr. Liu’s project titled “Investigating the
Ionospheric Scintillation Characteristics using Space- and Ground- Based GNSS
Observations in Hong Kong during Solar Maximum” is successfully selected to
fund by the RGC for 36 months. This is one of PolyU’s 138 GRF projects funded
by RGC this year. Dr. Liu was successfully funded in the past 3 years in a row.
One PhD student and one Research Associate (or Research Assistant) will be
recruited to work on this project. Applicants must send email to contact Liu
immediately.
[June 07, 2013] We are very
delighted that the MicroLARGE Lab has established the Hong Kong’s FIRST GNSS and Radiosonde
collocation station at Hong Kong Observatory’s facility at King’s Park,
Kowloon, Hong Kong. This is the first time that the GNSS station is established
just nearby the Hong Kong’s only Radiosonde station. Both GNSS receiver and
Radiosonde are used to observe atmospheric water vapor. The collocation of two
observation techniques allows a direct comparison of the water vapor
measurements of these two methods. The Radiosonde technique is traditionally
believed a standard reference to which other water vapor observation technique
should be compared. The establishment of such a facility will allow our
researchers to gain more data to study the atmospheric water vapor changes in
Hong Kong and to have more insightful understanding of the observation accuracy
of each method.
[L to R: Dr. Weiwei Song (PolyU),
Mr. Engineer (HKO), Dr. David Lam (HKO), Mr. Wang-chun Woo (HKO), Dr. George
Liu (PolyU)]
[L to R: Mr. Biyan Chen (PolyU), Dr.
Weiwei Song (PolyU), Mr. Engineer (HKO), Dr. David Lam (HKO), Mr. Wang-chun Woo
(HKO)]
[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.
[May. 22, 2013] 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. This research work was
supported by the General Research Fund (GRF) of Hong Kong
Research Grants Council (RGC).
[May
11, 2013] We are very
pleased to announce that Dr. George Zhizhao Liu was given an honor of
Individual Award of Shenzhen Virtual University Park
for National Research Project,
by the Shenzhen Municipal Science and Technology Innovation Council December
2012.
[Jan. 04, 2013] Dr. Liu and his research team visited the Hong Kong
Observatory, Hong Kong Special Administrative Region (HKSAR). Dr. Liu was also
invited to give an open presentation titled “GNSS for Precise Water Vapor and
Ionosphere Space Weather Monitoring” for the HKO colleagues. Dr. Liu and his
team were guided by Mr. S. T. Chan, Senior Scientific Officer of HKO, to visit
the weather forecasting center.
[Dec. 12, 2012] The Inaugural Early Career Award Recipient (首届“杰出青年学者奖”), Hong Kong Research Grants Council (RGC), Hong Kong
Special Administrative Region (HKSAR). Dr. Liu was one of the 19 recipients out
of 334 applicants across all the universities in Hong Kong in 2012 (success
rate: 5.69%). He is also one of only 3 recipients in PolyU and one of 6
recipients in the Engineering Panel under Hong Kong RGC.
Dr. Liu received the Early Career
Award from the Chairman of the Engineering Panel of Hong Kong Research Grants
Council (Dec. 12, 2012)
The six recipients of Early Career
Award of the Engineering Panel and the Engineering Panel Chairman of Hong Kong
Research Grants Council (Dec. 12, 2012)
[July 23, 2012] We are pleased to
share with you that our research project “Innovative Real-Time Cycle Slip Detection and Rectification for
High Precision GPS Positioning” led by Dr. George Zhizhao Liu is
funded by the Early Career Scheme (ECS), Hong Kong Research Grants Council
(RGC), Hong Kong SAR Government. This project, together with 19 other projects
across all the universities in Hong Kong, will be recognized with an
“Early Career Award” (ECA), which is the first time to give ECA
in the history of Hong Kong RGC.
For this project, one PhD student
will be funded for three (3) years. Interested applications are welcome to
contact Dr. Liu.
[July 23, 2012]
We are pleased to share with you that our paper “Cycle slip detection
and repair for undifferenced GPS observations under high ionospheric activity”
co-authored by Changsheng Cai • Zhizhao Liu • Pengfei Xia • Wujiao Dai is
published online @ GPS Solutions 4 July 2012. As of 23 July 2012
(20 days after the online publication), this paper has been downloaded 174 times, ranked 2nd in the
list of most downloaded papers in the 30-days category. This paper can be
downloaded @ http://www.springerlink.com/content/k214871257361300/
[May 29,
2012] The Hong Kong GPS-based Real-time Water Vapor
Monitoring System (GRWVMS) has been successfully operating more than 40 days
(since its first day 19 April 2012). This is one of the countable GRWVMS in the
world. To our knowledge, similar systems are only available at a limited number
of organizations, such as:
1. USA: NOAA http://www.gpsmet.noaa.gov/
2. USA: UCAR Suominet network: http://www.suominet.ucar.edu/
3. Netherlands: KNMI (Royal Netherlands
Meteorological Institute) http://www.knmi.nl/research/weather_observations/gps/real_time_IWV.html
[February
10, 2011] As of 10 Feb. 2011 our
paper (link
here) is ranked one of the 5 most downloaded papers in Journal of Geodesy
based on the downloads in the past 77 days since its first day of online
publication, one of the internationally well recognized journals in Geomatics.
This paper developed a
fully automated cycle slip detection and repair algorithm for dual-frequency
GPS carrier phase measurements. It can be safely said that the cycle slip
problem that have been hanging over the GPS community as long as the GPS
history itself (~30 years) is well resolved.
This algorithm is extremely
effective for high rate GPS data like 1Hz or higher. Virtually any size of
cycle slips can be detected and repaired.
For low rate GPS data (like
30 sec data interval or larger) this algorithm can work for many cycle slip
cases but it might be a little difficulty for small cycle slips.
This method has been extensively
tested and examined in many scenarios such as:
o
High dynamics (space-borne GPS receiver payload on COSMIC
satellite)
o
Highly disturbed ionosphere (daily Kp index =7.6 on 31 March
2001, the 4th highest daily Kp value in the past 30 years)
We look forward to hearing
your feedback and your comments/suggestions are always welcome.
Geomatics, an incredibly critical technology in
this information era!
[April 21,
2010] I am very pleased that
my students have produced a beautiful Google Earth KML map based on their final
year project. In their final year project, the 3-girl group used the GPS RTK to
survey one of the most popular cycling paths in Hong Kong (from Tai Po to Sha
Tin). It is quite safe to say this Google Earth map for this HK cycling path is
the most comprehensive, the most accurate (only a few centimeters of error)
information that is accessible for free by the general public.
You can download this Google Earth KML map to
your computer from here
(right click mouse and save link as …). If you don’t have the Google Earth yet,
you can download it for free from earth.google.com
[Jan.10,
2010](This is an excerpt of my speech given May 05, 2007 at my Toastmaster
club). In this world, scientists, engineers, researchers, and actually many
people are working hard every day to try to answer the following 6 most
fundamental questions more correctly and more precisely:
1) When 2)
Where 3) Who 4)What
5)Why 6)How
At present,
we can easily answer “When” in a completely numerical way because our time has
been digitalized, for instance: the UTC time at this point of writing is:
2010-01-19 15:22:20. The numerical expression of time is an important progress
in human being history and it is essential in this information era. So how
about the other 4W1H questions? Can you also use numbers to answer the
remaining 4W1H questions? Answer is yes or no. If you use Geomatics technology,
you can answer the Where numerically too. Without geomatics,
you can’t. Why? The answer is simple. For example, Hong Kong’s latitude and
longitude is: 22°20
North, 114°11 East. So
you can see the location of Hong Kong can be easily described in numeric
numbers. How to get these numbers? It is a part of geomatics technology – using
Global Positioning System (GPS). With GPS, you may locate anywhere in the world
numerically and display it on your computer screen. This is the power and
beauty of geomatics technology – answering one of the world’s most fundamental
questions “WHERE” in a numerical way, a way people have never thought of and a
way that is so critical in today’s information era.
With GPS technology,
now any objects in our 4-dimensional space-time domain can be completely
digitalized and numerically stamped. This is the contribution our geomaticians
are making to the society.
[Dec03,
2009] Immediate
Research Associate Post Open: (!new!)
There is
currently one Research Associate Post open. The interested ones can find more
1.
information here (English
Version) or (Chinese Version).
Thank you!
[Dec03,
2009] On December 3rd, 2009, this website is drastically modified
and improved to the current version. If you have an interest to join this group
or have any comments, please don’t hesitate to contact us.
[Dec01,
2009] On December 1st, 2009, I am very pleased to welcome Rui Xu to
the Micro-LARGE. She is the first student and first PhD student joining this
Lab. She is from Nanjing University of Aeronautics and Astronautics (NUAA) and
will complete her PhD studies under the joint
supervision
of Prof. Wu Chen and myself. Welcome Rui!
[May 26, 2013] Recently, a paper was
coauthored by Zhizhao Liu, Rui Xu, Yu Morton, Jisheng Xu, Wouter Pelgrum, Steve
Taylor, Wu Chen and Xiaoli Ding.
[May. 22, 2013] 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).
[May. 11, 2013] We are very pleased to announce that Dr. George
Zhizhao Liu was given an
honor
of Individual Award of Shenzhen Virtual University Park for National Research
Project, by the Shenzhen
Municipal
Science and Technology Innovation Council December 2012.
[Dec. 12, 2012] The Inaugural Early Career Award Recipient (首届“杰出青年学者奖”), Hong Kong Research Grants Council (RGC), Hong Kong
Special Administrative Region (HKSAR). Dr. Liu was one of the 19 recipients out
of 334 applicants across all the universities in Hong Kong in 2012 (success
rate: 5.69%). He is also one of only 3 recipients in PolyU and one of 6
recipients in the Engineering Panel under Hong Kong RGC.
[July 23, 2012] We are pleased to
share with you that our research project “Innovative Real-Time Cycle Slip Detection and Rectification for
High Precision GPS Positioning” led by Dr. George Zhizhao Liu is
funded by the Early Career Scheme (ECS), Hong Kong Research Grants Council
(RGC), Hong Kong SAR Government. This project, together with 19 other projects
across all the universities in Hong Kong, will be recognized with an “Early Career Award” (ECA), which is
the first time to give ECA in the history of Hong Kong RGC. For this project, one PhD student will be
funded for three (3) years. Interested applications are welcome to contact Dr.
Liu.
[July 23,
2012] We are pleased to share with you that our paper “Cycle
slip detection and repair for undifferenced GPS observations under high
ionospheric activity” co-authored by Changsheng Cai • Zhizhao Liu • Pengfei Xia
• Wujiao Dai is published online @ GPS Solutions 4 July 2012. As
of 23 July 2012 (20 days after the online publication), this paper has been
downloaded 174 times, ranked 2nd
in the list of most downloaded papers in the 30-days category. This paper can
be downloaded @ http://www.springerlink.com/content/k214871257361300/
[14-15May 2012, Hong Kong]We are very pleased to announce theGNSSSchool(click
for announcement) will be held attheDepartment ofLSGI,Hong Kong PolytechnicUniversity, 14-15 May 2012. Five distinguishedresearchers will give lectures for
the GNSS School. The registration fee isonly HK$200 (approx. US$25).
Dr. Jade Morton: How
GNSS Signal ProcessingAlters Signal Parameters: A Cautionary Tale in Using GNSS
for Remote SensingApplications
Dr. PeterTeunissen: Carrier-Phase GNSS Attitude Determination
Dr. Maorong Ge: PPP AlgorithmsDr. Peng Fang:Global and Regional Reference Frame: Establishment, Maintenance, and Application
Dr. Danan Dong:Dig out signals from deep interior of the Earth using GPS measurements
[14 May 2012,
HongKong]Dr. Jens Wickert, Acting headof
section 1.1 “GPS/Galileo Earth Observation”
German Research Center for Geosciences GFZ,
Potsdam,Germany is invited to give a talkon“GPS/Galileo Earth Observation at GFZ: Recent activities and results” attheHong Kong
PolytechnicUniversity.
[22 March 2012, Hong Kong]
Dr.George Liu was invited to give a talk at theCivilEngineering and Development Department, Hong Kong Special Administrative Region(HK
SAR) Governmenton “Monitoring Equatorial andLow-latitude Ionospheric Scintillation and
Assessing Scintillation Impact onSatRef Network and GPS Applications in Hong
Kong”.
[13 March 2012, Hong Kong]
Weare very glad that our paper “A multi-sensor study of
watervapour from radiosonde, MODIS and AERONET: a case study of Hong Kong” was published
atINTERNATIONAL JOURNAL OF CLIMATOLOGY in December 2011. This paper
wascoauthored by
Zhizhao Liu, Man Sing
Wong,Janet Nichol and P. W. Chan. The citation is:Zhizhao Liu, Man Sing
Wong,Janet Nichol and P. W. Chan (2011),Amulti-sensor study of water vapour from
radiosonde, MODIS and AERONET: a case studyof Hong Kong,Int. J. Climatol.DOI:
10.1002/joc.3412.
[09 March 2012, Hong Kong]
Dr.George Liu was invited to give a talk at theBeijingUniversity of Aeronautics and Astronautics (BUAA)on “An innovative approach for successful cycle slip detection and fix
even with arbitrarily large pseudorange errors”.
[08 March 2012, Hong Kong]
Dr.George Liu was invited to present the Compass (Beidou) receiver
evaluationresults at the Unicore Communications Inc. Beijing with a title “Preliminary Quality Analysis of the Pseudorange and Carrier
PhaseData from Unicore Compass+GPS Receiver”.
[17 February 2012, Hong
Kong]Dr. George Liu was invited to give a talk at the Chinese University of
HongKong on “Water Vapor Observation in
HongKong by Radiosonde, AERONET and MODIS”.
[17 January 2012, Hong
Kong]Dr. George Liu is glad to receive fund support for the research “Improving the GPS
SurveyingProductivity in Construction by Modeling the Localized Errors in the
GPSNetwork—Case Study with Hong Kong’s SatRef Network” from Construction Industry
Institute Hong Kong /PolyU Innovation Fund Governing Council. Thank youConstruction Industry
InstituteHong Kong / PolyUInnovation Fund Governing Council!
[05 January 2012, Hong Kong]Dr. Jade Morton, Professor atthe Department of
Electricaland Computer Engineering,Miami U, USA,was invited to give a talk atthe Department ofLSGI,Hong Kong PolytechnicUniversity on the topic “Ionosphere Effects and other GNSS
and RF Navigation Research atMiami”.
[03 January 2012, Hong
Kong]Dr. George Liu was invited to give a talk at the Hong Kong Observatory
(HKO) on“Preliminary Investigation of Real Time PWV Monitoring in Hong Kong”.
[20 November 2011, Hong
Kong]Dr. George Liu was invited to give a talk at the Wuhan University, China
on “Evaluating Water Vapor Observed by
Radiosonde, AERONET and MODIS inHong Kong”.
[11 October 2011, Hong Kong]Dr. Naser El-Sheimy, Professor at
theDepartment of Geomatics Engineering, U of Calgary, Canada,was invited to give a talk
atthe Department ofLSGI,Hong Kong
PolytechnicUniversity on the topic “EmergingMEMS
Sensors and Its Impact on Mapping and Navigation Applications”.
----------------------------------------------------------------------------------------------------------------------
Last updated
[24September
2011, Hong Kong] We are very pleased to announce thatmultiple MSc level projects are available for
thenew MSc students. The interested students are welcome
tocontact Dr. George Liu by a visit HJ728 or an emaillszzliu@polyu.edu.hkor a
call 27665961.
[24September
2011, Hong Kong]
[24September
2011, Hong Kong] We are very pleased to announce that ourGeneral Research Fund(GRF)
application tothe Hong Kong ResearchGrants
Council (RGC)was successfully fundedafter a
fierce competition.Thetitle of this project is “3D Water Vapor TomographicModeling by Assimilating
Multiple Sensors to Support Extreme WeatherForecasting in Hong Kong and
Mainland China”.
[24September
2011, Hong Kong] Our publication was reported in“Science Letter”on 7 June2011.
[24September
2011, Hong Kong]As of 23Feb. 2011our paper(link here)wasranked 3rdin the most downloaded papersin
Journal of Geodesy based on the downloads in the past 90 days since itsfirst
day of online publication, one of the internationally well recognizedjournals
in Geomatics.
As of 10 Feb. 2011ourpaper(linkhere)is ranked one
of the 5 most downloaded papers in Journal of Geodesybased on the downloads in
the past 77 days since its first day of onlinepublication, one of the
internationally well recognized journals in Geomatics.
This paper developed afully
automated cycle slip detection and repair algorithm for dual-frequencyGPS
carrier phase measurements. It can be safely said that the cycle slipproblem
that have been hanging over the GPS community as long as the GPShistory itself
(~30 years) is well resolved.
This algorithm is
extremelyeffective for high rate GPS data like 1Hz or higher. Virtually any
size ofcycle slips can be detected and repaired.
For low rate GPS data
(like30 sec data interval or larger) this algorithm can work for many cycle
slipcases but it might be a little difficulty for small cycle slips.
This method has
beenextensively tested and examined sin many scenarios such as:
o
High dynamics (space-borne GPS receiver payload on
COSMICsatellite)
o
Highly disturbed ionosphere (daily Kp index =7.6 on 31
March2001, the 4thhighest daily Kp value in the past 30 years)
We look forward to
hearingyour feedback and your comments/suggestions are always welcome.