Literature review on estimating ice thickness

This report is a literature review on how to estimate ice thickness using satellite altimeter and satellite SAR. A presentation is given on ice, the properties of ice and on how sea ice and the ocean reflect back to the SAR satellite. It is important to have knowledge of the sea ice volume, sea ice export, and of how the ice varies inter-annually due to climate changes, as well as oil and gas exploitation, ship traffic, and new ship routes in the north. Much research has been done on how to estimate the sea ice freeboard using a satellite altimeter, for example ICESat and CryoSat-2. Some of the results show good agreement with in situ measurements. The data show a decline in the sea ice volume in the Arctic over many years. Many different attempts have been made to estimate the sea ice thickness using satellite SAR. It has been claimed that it is impossible to estimate the sea ice thickness using SAR alone. Trials have been done to estimate the sea ice thickness by using satellite SAR. Some background information is necessary to be able to estimate the sea ice thickness by using SAR. It is for example necessary to localize areas with thin ice before it is possible to estimate the sea ice thickness. Many of the trials that have been done to estimate the sea ice thickness with SAR have been successful, but the estimates have been done within a certain thickness range where the approximate sea ice thickness is known in advance. If different methods are used to estimate the thickness of thin and thick ice, the chances are better to get the sea ice thickness estimate correct.