Single-pass Interferometric SAR satellite configurations offer unique opportunities for observing dynamic features of ice masses. Future cross-track interferometry constellations of satellite missions will produce interferometric DEMs over virtually all glaciers globally and will offer significant advancements for regular monitoring their surface elevation. In the present contribution we want to address some of the main issues encountered when mapping the topographic changes with multitemporal TanDEM-X InSAR DEMs over glaciers. We illustrate open questions for InSAR DEM data acquisition when targeting height change rate calculation for mountain and outlet glaciers at large scale.

We estimate the seasonal impact in the ice velocity of the entire South Patagonian Icefield (SPI), the velocity mosaics from 2016 (Winter/Autumn), 2017(Summer/Spring) and 2018(Summer/Spring) were combined to obtain acceleration and deceleration maps. Additionally, a more detailed study was made for seven glaciers in particular, the freshwater Upsala, Viedma, Moreno, O’Higgins and the tidal influenced Pio XI, Jorge Montt, Amalia.

The Extended Timing Annotation Dataset (ETAD) product provides timing corrections for Sentinel-1 (S-1) single-look complex (SLC) data for improved geometric accuracy. Given the close relationship between path delay and radar signal phase, it also has the potential to serve as the basis for phase corrections in SAR interferometry (InSAR) applications with Sentinel-1. The provided timing corrections may be converted to phase offsets, which can be used to derive interferometric phase screens between pairs of repeat-pass acquisitions. In this work we explore the capabilities and limitations of ETAD to provide accurate interferometric phase corrections and introduce new features currently under investigation in the context of S1-ETAD scientific evolution study.

Accurate identification of grounding lines is of immense importance for estimating the mass budgets of ocean-terminating ice sheets and glaciers of Antarctica and Greenland. In Differential Interferometric SAR (DInSAR) interferograms, human experts still largely manually digitize grounding lines. The time-consuming nature of this task makes it infeasible to produce timely, continent-wide grounding line mappings. This study employed a Deep Neural Network (DNN) to automate delineation. The Holistically-Nested Edge Detection (HED) network was trained in a supervised manner on features derived from interferometric phase, elevation data, ice velocity, tidal amplitude, atmospheric pressure and corresponding manual delineations. HED-generated lines achieved a median deviation of 209 m with a median absolute deviation of 153 m from manual delineations. The developed automatic pipeline demonstrates the potential for generating spatially and temporally dense mappings of the grounding line.

This paper introduces the extended timing annotation dataset (ETAD) product for Sentinel-1 (S-1) which was developed in a joint effort of German Aerospace Center (DLR) and the European Space Agency (ESA). It allows to correct range and azimuth timing of S-1 images for geophysical effects as well as for inaccuracies in synthetic aperture radar (SAR) image focusing. In combination with the precise orbit solution, these effects determine the absolute geolocation accuracy of S-1 SAR images and the relative collocation accuracy of repeat pass image stacks. ETAD contains the gridded timing corrections for the tropospheric and ionospheric path delays, the tidal-based surface displacements, and the SAR processing effects, all of which are computed for each data take using standard models from geodesy and auxiliary atmospheric data. The ETAD product helps S-1 users to significantly improve the geolocation accuracy of the S-1 SAR products to better than 0.2 m and offers a potential solution for correcting large scale interferometric phase variations. The product layout and the product generation are described schematically. The paper also reports first results for different SAR techniques: first, the improvement in geolocation accuracy down to a few centimeters by verification of accurately surveyed corner reflector positions in the range-azimuth plane; second, the well-established offset-tracking technique, that is used for systematic ice velocity monitoring of ice sheets and glaciers, where ETAD can reduce velocity biases down to sub-centimetric values; and third, the correction of atmospheric phase contributions in wide-area interferograms used for national and European ground motion services. These early results proof the added value of the ETAD corrections and that the product design is well suited to be integrated into the processing flows of established SAR applications such as absolute ranging of targets, speckle/feature tracking and interferometry.

Individual drainage basins of ice sheets specify the glaciated area that is drained by a single outlet glacier. These catchments are needed to partition mass balance measurements to the single glacier level. Until now complete glacier inventories that contain annotated basin information are missing for the Earth's two ice sheets. Here we present delineations of all major outlet glacier catchments in Northeast Greenland that have been produced by a modified watershed algorithm using TanDEM-X elevations and Sentinel-1 velocity measurements. The approach shows the potential to generate a complete basin inventory for entire Greenland and Antarctica.

This paper presents an approach for automatic calving front delineation of marine-terminating outlet glaciers. We utilize a Canny edge detection approach together with a shortest path optimization problem to find calving front locations (CFL) on SAR backscattering images from Sentinel-1 and TerraSAR-X. The CFLs are detected on Stripmap images acquired over Zachariae Isstrœm in Northeast Greenland where difficult conditions for CFL retrieval exist. We compare our results to CFLs that are delineated by hand and find good agreement, independent of the used sensor.