The number of Earth observation satellites has increased dramatically over the past decade, with commercial satellites like the Pleiades and Worldview allowing the capture of two or more optical images at almost the same time (referred to as stereo images) at sub-metre resolution. Computer vision techniques can use these stereo images together with the optical parameters of the cameras to compute digital elevation models that are essential for a myriad of applications, including hydrology, urban planning and natural hazard detection.
These computational methods mimic the human vision system, where the brain receives the two slightly different images observed by each eye and compares them to give a person the perception of depth. Similarly, computer vision techniques compare stereo images to estimate the height of the objects captured in the scene and therefore automatically compute a 3D digital elevation model.
Researchers from Centre National D’Études Spatiales (CNES) have developed a processing pipeline to compute a digital elevation model (DEM) at a resolution of 30 cm using stereo images from the Pleiades satellite. However, the major limitation of the existing pipeline is that the algorithm is not sufficiently accurate and provides distorted models with missing data.
The SATINET project is a new project within the Data Science Research Platform (DSRP) and the Department of Communications and Computer Engineering (CCE) at the University of Malta. This is a collaborative project between the University of Malta and CNES aimed to improve the performance of the existing processing pipeline. We are using artificial intelligence to improve the accuracy of the stereo matching process adopted in the existing processing pipeline.
Dr Reuben Farrugia is a senior lecturer with the CCE Department and co-ordinator of the DSRP at the University of Malta. Project SATINET is financed by the Malta Council for Science & Technology, for and on behalf of the Foundation for Science and Technology, through the MCST-CNES Space Bilateral Fund.
Did you know?
• Some viruses can infect bacteria. These are known as bacteriophages, or phages.
• You get carsick when reading or using a phone because the inner ear knows you are moving, but the eyes think you are still. As a result, the body thinks it has eaten something poisonous and is hallucinating. The reaction is nausea or worse.
• The earliest known human cremation took place around 7,000BC in the Near East. This was revealed through a dig that exposed the remains of a young adult whose bones had damage consistent with purposeful burning of a body.
• 2020’s Earth Overshoot Day occurred on August 22, the day when we have consumed more than the sustainable share of resources that the Earth can replenish in a year.
For more trivia see: www.um.edu.mt/think
Sound bites
• Researchers have discovered which gut bacteria help our immune system battle cancerous tumours and how they do it. The discovery may provide a new understanding of why immunotherapy, a treatment for cancer that helps amplify immune response, works in some cases, but not in others. The findings show combining immunotherapy with specific microbial therapy helps the immune system to recognise and attack cancer cells in three forms of cancer.
https://www.sciencedaily.com/releases/2020/08/200813144920.htm
• Researchers at the University of Bristol reveal that young people felt less anxious and more connected to school during lockdown. More than half (54 per cent) of the 13- to 14-year-old girls surveyed last October showed they were at risk of anxiety, compared to 26 per cent of boys of the same age. When surveyed again in May, during the pandemic which forced schools to shut and placed unprecedented restrictions on people’s lives, the figures dropped by nearly 10 per cent among girls (45 per cent) and to less than one in five of boys (18 per cent). This raises questions about how the school environment affects some younger teenagers’ mental well-being.
https://eurekalert.org/pub_releases/2020-08/uob-rry082120.php
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