Over 2,000 satellites are currently orbiting our planet, travelling across the skies thousands of kilometres above our heads at blazingly fast speeds. These satellites gather important information about the physical, chemical and biological systems on Earth, measuring parameters such as land and sea surface temperatures, vegetation and forest cover, the state of polar ice caps as well as the presence of gases and aerosols in our atmosphere. They are also used to monitor mankind’s effects on the planet, from urban development to defores­tation and climate change.

Copernicus is the European Union’s Earth Observation programme and is mainly powered by the Sentinel satellite missions. Sentinel 1 provides Synthetic Aperture Radar data, while Sentinel 2 and Sentinel 3 provide optical and thermal data respectively. Thermal data allow scientists to measure sea surface temperature (SST), which is useful in applications such as climate change monitoring and weather forecasting. Sentinel 3 provides SST at a resolution of one kilometre per pixel, which is sufficient for most ocean applications; however, is problematic in coastal areas due to the interface between land and sea.

Sentinel 3 passes over Malta every one to two days, providing regular images that are an important input in hydrodynamical forecasting models that predict the direction and strength of marine currents.

Meanwhile the Landsat-8 satellite operated by the US Geological Survey has a 100-metre resolution, but passes over Malta every 16 days, making it unsuitable for forecasting models.

At the University of Malta, a multidisciplinary team is working on the SAT-FIRE (SATellite data Fusion and Imaging Resolution Enhancement for coastal areas) project. The objective is to use machine learning and computer vision techniques to improve the resolution and quality of the existing Sentinel-3 thermal satellite imagery using the high-resolution Landsat-8 imagery, resulting in better marine current forecasting for the coastal areas, benefiting divers, swimmers, mariners and tracking of debris.

Due to the presence of unwanted stripes introduced by measurement errors in the Landsat 8 data (top-left image), the research team has developed a novel destriping filter, which removes these stripes. The researchers could then train a Convolutional Neural Network using deep learning, improving the Sentinel 3 resolution to 200m per pixel. The results are shown in the bottom-right image. The generated high-resolution SST data is currently be­ing used to validate the current forecasting models, and potentially improve their accuracy.

Dr Ing Gianluca Valentino is a lecturer at the Department of Communications and Computer Engineering at the University of Malta, and the principal investigator of the SAT-FIRE project.

Project SAT-FIRE financed by the Malta Council for Science & Technology for and on behalf of the Foundation for Science and Technology, through the Space Research Fund.

Sound bites

• There are many reasons why we should avoid fatty foods. Researchers have now added concentration to the list. A new study suggests that eating one meal high in saturated fats hinders the ability to concentrate. Researchers suggest that the impacts of high-fat food can be even worse when you consider stress levels, such as the situation of the current pandemic, when people turn to fatty foods for comfort.

https://www.sciencedaily.com/releases/2020/05/200512134433.htm

• Researchers have discovered a strong correlation between severe Vitamin D deficiency and mortality rates from COVID-19. The study was aimed at looking into why mortality rates differ from country to country. The cytokine storm – a hyperinflammatory condition caused by an overactive immune system – doesn’t seem to occur when patients have normal levels of Vitamin D. However, researchers point that excessive doses of Vitamin D have several side effects.

https://www.sciencedaily.com/releases/2020/05/200507121353.htm

For more soundbites listen to Radio Mocha www.fb.com/RadioMochaMalta/

Did you know?

• The International Space Station (ISS) orbits the Earth 16 times a day and tra­vels at 28,000 km/hr – equivalent to 10 times the speed of a bullet on earth.

• The ISS acts as a spacecraft, observatory, laboratory and a home to up to 10 people at one time, floating 400 kms above the Earth’s surface.

• ISS started in 1998 as a space-based research endeavour between 15 countries, representing one of the largest peace-making, cross-national collaborative projects of all time.

• It is possible to explore the ISS for yourself in Google’s Street View and get an astronaut’s eye-view of the Earth.

For more trivia see: www.um.edu.mt/think