[CIC-See What I See] Leveraging Satellite Remote Sensing Technology to Build a Safer Hong Kong

New technological developments can bring about transformation in the construction industry by improving efficiency. Recently, world-renowned geologist Mei-Po KWAN – who is also the Director of the Space and Earth Information Institute and Professor of Geography and Resource Management at The Chinese University of Hong Kong (CUHK) – spoke at a See What I See event about the potential of satellite remote sensing and other advanced technologies to enhance safety of both construction sites and Hong Kong’s overall infrastructure, benefitting both the construction industry and social development.?

Scientific Support for Satellite Surveillance

Founded in 2015, CUHK’s Institute of Space and Earth Information (ISEIS) focuses on research in space and Earth information science. It uses its own ground-based satellite receiving station to carry out research on geospatial intelligence (GeoAI), health geography, multi-source remote sensing environment monitoring and virtual geographic environments (VGE). Through its environmental monitoring and study of changes on the ground, it provides scientific support and solutions for urban planning and other areas of activity.

Professor KWAN explains: “So what do we actually do? We are combining sky, space, Earth and human beings. We not only receive information from remote sensing satellites, unmanned aerial vehicles (UAV) and the Bei Dou satellite, but also use proprietary technology to process different satellite images and AI to process different data.”

In the past, public concerns were often raised when problems of structural deformation and even settlement occurred at construction sites. Satellite remote sensing imagery can help building work and structures to be more effectively monitored, as well as project progress, quality and site safety. According to Professor KWAN, with these technologies helping to improve site safety, the construction industry could continue to attract new blood. More importantly, satellite remote sensing, through real-time monitoring, can observe the condition of structures under construction, detecting any deformation and giving advanced warning.?

Currently, Hong Kong International Airport and the Hong Kong portion of the Hong Kong-Zhuhai-Macau Bridge are using satellite remote sensing to monitor for infrastructural deformation and evaluate potential risks. The technology offers five times more frequent observations than traditional ground surveillance and its accuracy is as precise as two millimetres.

?Urban Physical Examination Increases Building and Infrastructural Safety

As early as year 2000, the Hong Kong Innovation and Technology Bureau was collaborating with the National Ministry of Science and Technology on a radar remote sensing project which included safety testing and evaluation of infrastructural facilities and building structures. Termed ‘urban physical examination’, this aimed to discover potential issues and risks as early as possible and ensure that city operations could safely continue.

ISEIS is using remote sensing to collect information from multiple sources, including synthetic aperture radar (SAR) and optical images, integrated with ground measurement data for analysis. All these collected data could also be applied to urban planning, environment surveillance, disaster emergency risk assessment or smart transportation systems, as well as to construction safety and promotion.

Professor KWAN explained that the use of images created with interferometric synthetic aperture radar (InSAR) time series to monitor building deformation and issue warnings has already helped to predict serious disasters and minimise losses.?

ISEIS has also used unmanned aerial systems and low altitude sensing to monitor construction sites, detecting issues such as waste accumulation, improper storage and damaged safety nets so that preventative measures could be implemented.

The institute has built a 3D noise modelling system to assess the noise level of each and every floor of every building in Hong Kong. This technology that could also be usefully applied at construction sites to measure and ultimately alleviate their noise problems.?

“Industrial safety always involves human activity. Mobile sensing technologies, using equipment such as smartphones to collect data, could examine site environments, noise levels and air quality for the implementation of appropriate preventive measures and improvement of site safety,” Prof. KWAN observed.

The Professor added that satellite remote sensing integrated with other data and sensing technologies would help to build a ‘Smart City Environment Sensing System’. This would monitor health-affecting factors such as air and noise pollution to enable effective preventative measures to be emplaced – a so-called ‘urban physical examination’. Professor KWAN remarked that it is encouraging that HKCU would launch the first Hong Kong-financed satellite for monitoring and research, as it may prove vital in building a healthier and safer city.

Using Science and Technology to Strengthen Knowledge Exchange

As Ir Thomas Ho, Chairman of CIC, said: “Making use of technology is indeed very important to the construction industry. For this purpose, we have to seize every opportunity to communicate with different parties, especially those on the mainland. To this end, the Council organised the ‘Forum of China ConTech Development and the Future of Hong Kong’s Construction Industry’ to discuss the latest trends in Mainland construction technologies, and developments and opportunities in Hong Kong’s construction industry. The Forum has been a very successful platform for scientific and technological exchange and cooperation between Hong Kong and the Greater Bay Area.”

On a related note, smart facilities management systems have become essential to property management. The Smart Facilities Management Control Centre located at the Kowloon Bay campus of the Hong Kong Institute of Construction was established at end of August 2023. It is a collaborative space and a showcase for an array of technologies such as digital twin, BIM, AI and big data, and promotes digitalisation of property management and exchanges of technological information for enhancing the overall quality and efficiency of property management.

In the future, CIC and other industry organisations will continue to work together on providing? exchanges and training on the latest construction technologies. Together, the construction industry will elevate its efficiency and safety standards and create a better future for all

【香港建造新視野】善用衞星遙感 ???建構更安全香港

科技發展能為建造業帶來變革，大大提升效率。早前，議會邀請了國際著名地理學家、現任香港中文大學太空與地球信息科學研究所所長兼卓敏地理與資源管理學教授關美寶教授出席「香港建造新視野」活動，分享如何透過衛星遙感技術 (satellite remote sensing technology) 以至其他新科技提升建造業以至本港整體基建的安全，為建造業和社會發展帶來裨益。

衛星監測 ?科學支援

香港中文大學太空與地球信息科學研究所於2015 年成立，專注於太空科學和地球信息科學領域的研究。硏究所運用自建的地面衛星接收器，進行包括地理空間智能(geospatial AI)、健康地理學 (health geography)、多源遙感環境監測 (multi-source remote sensing environment monitoring)和虛擬地理環境(virtual geographic environments)研究，透過對環境進行監測，研究地面變化，為城市規劃等領域提供科學上的支援和解決方案。

關教授說：「研究所的工作可以用四個中文字：『天、空、地、人』槪括。我們運用人造衛星獲取遙感影像，結合由無人機等途徑收集的資料數據，進行全面的地球觀測，再利用人工智能，分析不同的地理現象。」

近年，有工地或建築中的設施變形甚至沉降，引起社會關注。利用衛星遙感技術獲取衛星影像，能夠監測建築工作、施工和建築物的結構，有助監控工程進度、質量和施工安全。關教授表示，有關技術能夠提升工地安全，故此亦有助建造業持續吸納新血。更重要的是，衛星遙感可用於監測建築中的設施結構，透過實時監控建築物的情況，如有變化可提前作出預警。

現時香港國際機場和港珠澳大橋香港部分亦採用衛星遙感監測基建可能發生的變形情況，評估潛在風險。這技術比傳統地面監察的頻率多五倍以上，精準度更細至2毫米。

「城市體檢」提升城市安全水平

香港創新科技及工業局早於2000年代初已經與國家科學技術部合作推行雷達遙感項目(radar remote sensing)，藉此對基建設施和結構安全進行檢測和評估，亦即俗稱的「城市體檢」，務求預早發現潛在問題或風險，確保城市運作和居民安全。

研究所利用多源遙感技術 (multi-source remote sensing) ，透過由不同來源取得資料，包括合成孔徑雷達(SAR)影像、光學影像，結合地面環境數據進行遙感分析。所獲得的各種地表信息可應用於城市規劃、環境監測、災害應急風險評估、智能交通系統以至建造業安全及推廣等領域，有助提升城市的整體安全水平，減少意外事故。

關教授表示，要預測地表的嚴重事故，可利用衛星遙感的InSAR (Interferometric Synthetic Aperture Radar) 時間序列 (time series)，透過拍攝到的InSAR影像，監測建築物變形等地面變化並作出預警，從而減低災害造成的損失。

除了衞星遙感技術，研究所還利用無人航拍機或系統，從地面低處監察建築工地有否廢料堆積、不當儲存、安全網破損等問題，從而作出預防。

研究所又建立了3D噪音建模 (3D noise modelling) ，評估本港每幢大廈甚至每個樓層的噪音水平，這亦可用於量度建築工地的噪音，舒緩工業噪音問題。

關教授表示：「工業安全往往涉及『人』的因素。利用移動感測技術 (mobile sensing technologies) ，即透過人們配備的傳感器材如智能手機收集數據，可實時監測建築工地的環境、噪音、空氣質量並作出相應預防措施，提升建築安全。」

她又說，衛星遙感技術結合其他數據源和感知技術，有助我們建立一套智慧城市環境感知系統。透過監測對人體甚至心理健康有影響的環境因素，例如空氣污染、噪音，有助制訂相應的健康建議和預防措施，並可為香港進行俗稱的「城市體檢」。關教授表示，令人振奮的是，中大將發射首顆由本港出資的人造衞星，用作監測研究，相信有助香港建立一個更健康安全的城市

善用科技 加強聯繫交流

正如議會主席何安誠所言：「善用科技對建造業的發展的確非常重要。我們應充分把握與不同地方尤其是與內地交流的機會。為此，議會早前便舉辦『中國建築科技發展與香港建造業未來』論壇，探討內地建築科技的最新趨勢，以及本港建造業的發展方向及可能面對的機遇，為香港與大灣區的科技交流和合作開展了一個極成功的平台。」

另一方面，智能化已是現今物業管理不可或缺的一部分，而議會轄下的香港建造學院位於九龍灣院校的「物業管理智能監察中心」已於2023年8月底開始運作，該中心為共享空間，透過運用和展示數碼分身(Digital Twin)、建築信息模擬(BIM)、人工智能及大數據等最新科技，積極推動本港物業管理數碼化和科技資訊交流，從而全面提升物業管理的質素與效率。

今後，議會和其他業界組織將不斷合作，繼續為業界提供與建造業相關的新科技交流及培訓，合力提升建造業效率和工業安全，務求為香港建造業打造更美好的未來。