Monitoring of coastal processes by using airborne laser scanning data

The three Baltic States and other Baltic Sea countries (Denmark, Finland, Germany, Poland, Russia and Sweden) share over 8,000 km of shorelines. Estonia has a shoreline length of approximately 3800 km, due to many islands, bays, and peninsulas. Coast monitoring with traditional surveying methods would be time consuming and expensive. Remote sensing by means of airborne laser scanning (ALS) could be an alternative to traditional coastal surveying methods. Accordingly, the aim of the study is to determine whether ALS data can be used to quantify volume changes along shorelines. The case study utilizes ALS data acquired by the Estonian Land Board in 2008-2011. The ALS flights are conducted in different altitudes (yielding a varying point density) and seasons (spring, summer). Study shows also that accuracy of readily available ALS data products may not be suited for the most demanding applications. Certain computational principles and methods need to be applied for remove systematical biases between different ALS campaigns. The methods and algorithms that where developed and tested during this study yield sub-decimetre accuracy for detecting contemporary coastal processes. Thus, ALS data can be used as an alternative to traditional coastal monitoring methods.