Time Series

One of the greatest advantages with satellite SAR technology is the reliable and periodical revisit of an area. In the case of Sentinel 1a the standard nominal revisit time is 12 days, and 6 days with the future addition of Sentinel 1b. This capability allows the powerful analysis of time series. For example attributing three SAR acquisitions of the same area into a single Red, Green and Blue colour composite, called a multi temporal SAR image. The RGB composite shows the changes of radar backscattering over the three acquisition dates by using colours, the stronger the backscatter the greater it contributes to the overall colour. The above example shows ship detection, using the following false colour composite combination: red= 22 December 2014; green=3 January 2014; blue=8 February 2015. Features which are consistent through the three acquisition remain greyscale, such as buildings and roads.