A new technique has been developed to suppress the noise in radar images of Titan captured by Cassini. The snaps are usually grainy in appearance due to electronic noise, but the new tool pulls back the curtain, providing the clearest view yet of Saturn’s largest moon.
Cassini has spent the last 10 years using its radar instrument to map the surface of Titan, revealing vast sand dunes and deep hydrocarbon seas. But until now, the images have always been distorted by electronic noise that made it difficult for scientists to interpret smaller features of the landscape.
The new technique – which the developers refer to as "despeckling" – uses an algorithm to modify the obscuring noise, transforming the existing images to produce views that are clearer and significantly easier to study.
Here the processed images can be seen below their unprocessed counterparts – each image represents an area 70 miles (112 km) wide (Image: NASA/JPL-Caltech/ASI)
The team received help developing the tool from a team of scientists based near Paris, who were already working on a de-noising algorithm. The Cassini team worked with them to adapt the model to the radar data collected by the distant orbiter.
The despeckled radar images have already been used by the team to create 3D maps of the moon’s surface, with a higher level of precision than was previously possible. They provide clearer views of Titan’s shorelines, river channels and vast desert-like expanses of dunes, and it’s even thought that the study of the noise itself may hold scientific value, potentially revealing information about the surface and subsurface of the moon.
While the images provided by the new tool are clearer than those that came before it, they’re currently being used selectively, as it takes significant fine-tuning to produce a single useful image, making it a time-consuming endeavor.
"This new technique provides a fresh look at the data, which helps us better understand the original images," said Stephen Wall, the deputy team leader of Cassini’s radar team. "With this innovative new tool, we will look for details that help us to distinguish among the different processes that shape Titan’s surface."