Earth shifts in colour

This gallery features a selection of results from the 2015 Fringe Workshop on advances in the science and applications of ‘SAR interferometry’.

Interferometric Synthetic Aperture Radar – or InSAR – is a remote sensing technique where two or more images over the same area are combined to detect slight changes occurring between acquisitions. Tiny changes on the ground cause changes in the radar signal and lead to rainbow-coloured interference patterns in the combined image, known as an ‘interferogram’.

The Fringe Workshop takes its name from these coloured fringes seen in the interferograms.

Precise measurements – down to a scale of a few millimetres – can be detected across wide areas. Tectonic plates grinding past one another, the slow ‘breathing’ of active volcanoes, the slight sagging of a city street through groundwater extraction, even the thermal expansion of a building on a sunny day.

The 2015 Fringe Workshop was held at ESRIN, ESA’s centre for Earth observation, in Frascati, Italy on 23–27 March.