A semi-automatic approach for estimating near surface internal layers from snow radar imagery

The near surface layer signatures in polar firn are preserved from the glaciological behaviors of past climate and are important to understanding the rapidly changing polar ice sheets. Identifying and tracing near surface internal layers in snow radar echograms can be used to produce high-resolution accumulation maps. This process is typically performed manually, which requires time-consuming, dense hand-selection and interpolation between sections, for each echogram. We have developed an approach for semi-automatically estimating near surface internal layers and have applied it to snow radar echograms acquired from Antarctica. Our solution utilizes an active contour (“snakes”) model to find high-intensity edges likely to correspond to layer boundaries, while simultaneously imposing constraints on smoothness of layer depth and parallelism among layers.