Today we gather to witness the signing of a Memorandum of Understanding between the Singapore Land Authority and the National Environment Agency to collaborate on an innovative use of positioning satellite data that will benefit Singapore.

About GNSS and its usage in navigation

Most people will think of positioning and navigation when terms like “GPS” or “GNSS” are heard. The Global Positioning System (GPS) which is one of the satellite positioning systems in the Global Navigation Satellite System (GNSS) together with the European Union’s GALILEO, Chinese BeiDou, Japanese QZSS

and Russian GLONASS, provides the capability to locate where you are and with the help of maps, enables wayfinding to your destinations.

SiReNT overview

SLA operates the Singapore Satellite Positioning Reference Network (or SiReNT) with nine (9) GNSS reference stations well distributed across Singapore. These 9 GNSS reference stations receive GNSS signals continuously 24/7 and are able to process and stream GNSS related information to users in real-time.

Currently, SiReNT is primarily used for precise positioning and navigation applications which include the surveying of property boundaries, mapping, construction automation, the development and operation of self-mobility platforms amongst many others.

Using GNSS data for atmospheric monitoring

Few would know that apart from navigation and positioning, GNSS has the lesser-known capability to measure how much water vapour content is in the atmosphere. When GNSS signals travel through the atmosphere, they are delayed by water vapour in the atmosphere. By calculating this time delay, the amount of water vapour between the positioning satellites and the SiReNT GNSS reference stations can be determined.

Weather analysis is conventionally carried out through the use of radiosondes and weather radars which provide humidity and rainfall patterns.

The capability of each SiReNT reference station to measure the water vapour content in its immediate area allows the Meteorological Services of Singapore (MSS) to obtain continuous and near real-time readings from SiReNT GNSS reference stations island wide. This additional data will augment MSS’s existing observation network data and can be used for exploratory studies for operational forecasting.

GNSS data for trend analysis and sustainability research

Looking ahead, the use of this rich GNSS database from SiReNT will allow better climate change related studies and activities as well. For a 5th year in a row in 2022, the World Economic Forum ranked extreme weather as the number one global risk in terms of the likelihood of happening, followed by the failure to adapt to climate change. Weather impacts socioeconomic activities locally and the introduction of advanced analytics and intelligent workflows together with the SiReNT atmospheric data, will allow better computations and understanding of how extreme weather and changing weather trends will impact infrastructures, assets, businesses, and customers.

A case in point is how Japan was recently experiencing a heatwave, whereas in previous years, June and July would have typically been rainy months. This is Japan’s worse heatwave since records began in 1875. Closer to home, the influx of huge durian stocks from Malaysia currently is also unexpected based on the weather trends from previous years, and this has delighted durian lovers in Singapore who can enjoy good quality fruits at lower costs.

Benefits of the MOU

With this MOU, NEA will have access to the rich SiReNT GNSS database without the need to build and maintain its own network of reference stations. Additionally with the nine SiReNT GNSS reference stations providing nationwide coverage, a higher spatial resolution of the atmospheric conditions over Singapore can be realised.

Through this collaboration, SLA gains an additional reference station, located in the Meteorological Services of Singapore’s Upper Observatory in Kim Chuan, for its SiReNT network. This would further enhance the redundancy and reliability of our island wide SiReNT network in providing precise GNSS services to its users.

Conclusion

Today is an important milestone that sees two agencies in distinct areas of public service finding a collaborative relationship that can be considered symbiotic in nature, for the betterment of Singapore. SLA will continue to work with partners on the usage of SiReNT GNSS data. We will continue to explore and push the boundary and discover other innovative uses where possible. The many experiences shared and gained from this collaboration will be a building block for future innovations in this field.