Operation Ice Bridge (OIB) was a flight campaign conducted in March and April 2009–2015 by NASA (Kurtz et al., 2013). The onboard snow radar provides snow depth measurements by identifying both the air–snow and snow–ice interface within the radar returns. This time difference can then be converted to snow depth, if the snow density is known. Furthermore, a combination of the onboard laser altimeter (tracking the ice + snow freeboard) with snow depth allows the calculation of SIT (Farrell et al., 2012).
