07 August 2020
Huge city-wide lunar lava tubes identified in new study
... has collapsed, leaving a circular hole that can be observed by overhead orbiters. Using satellite images and digital terrain models (DTMs) of lunar and Martian volcanic regions where skylights and other features known as collapse chains (collapsed...
October 2015
Copernicus, ESA’s most ambitious Earth Observation programme
... same site, this tandem operation boosted synthetic aperture radar interferometry applications particularly for the generation of digital terrain models (DTMs). In July 2011, ERS-2 was retired and the process of de-orbiting the satellite began. ESA...
