Velocity estimation of glaciers with physically-based spatial regularization — Experiments using satellite SAR intensity images

Maksymiuk, Oliver; Mayer, Christoph; Stilla, Uwe

doi:10.1016/j.rse.2015.11.007

Cited by 15 publications

(13 citation statements)

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“…For a detailed description of the processing chain see Fahnestock et al (2016). 20 The Landsat 8 satellite has a same-orbit revisit time of 16 days and a swath width of 185 km. Only scenes which are at least 50% cloud-free are used (as determined by the provided estimate in the metadata for the scenes).…”

Section: Golive Velocity Fieldsmentioning

confidence: 99%

“…Up to now, most studies of glacial velocity have had an emphasis on either spatial or temporal detail. When temporal detail 20 is present, studies focus on a single or a handful of glaciers (Scherler et al, 2008;Quincey et al, 2011;Paul et al, 2017). On the other hand, when regional assessments are the focus, the temporal resolution ranges from a single time stamp up to annual resolution (Copland et al, 2009;Dehecq et al, 2015;Rosenau et al, 2015).…”

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confidence: 99%

“…Furthermore, most studies rely on filtering in the post-processing of vector data by using the correlation (Scambos et al, 1992;Kääb and Vollmer, 2000) or through median filtering within a zonal neighborhood (Skvarca, 1994;Paul et al, 2015). Some sophisticated post-processing procedures are 25 available (Maksymiuk et al, 2016), but rely on the coupling with models based upon the Navier-Stokes equations. Also geometric properties can be taken into account during the matching to improve robustness and reduce post-processing efforts, such as reverse-correlation (Scambos et al, 1992;Jeong et al, 2017) or triangle closure (Altena and Kääb, 2017a).…”

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confidence: 99%

“…The edges can be directed, meaning it can assign which acquisition is the master (reference) or the slave (search) image during the matching procedure. For the GoLIVE data, the oldest acquisition is always the reference image, 20 hence within the matrix only the upper triangular part has filled entities. The spacing of the timesteps is 16 days and the amount of days is set into the corresponding entries when a time step is covered by an edge.…”

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confidence: 99%

“…For this study we implement a three-dimensional Hough space, which for our toy example will look like as in figure 4b, though due to visualization limitations, the fuzzy borders are not visualized. 20 The advantage of a Hough search space is the resistance to multiple outliers. It builds support and is not reliant on the whole group of observations.…”

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confidence: 99%

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Extracting recent short-term glacier velocity evolution over Southern Alaska from a large collection of Landsat data

Altena

Scambos

Fahnestock

et al. 2018

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The measurement of glacier velocity fields using repeat satellite imagery has become a standard method of cryospheric research. However, the reliable discovery of important glacier velocity variations on a large scale is still problematic, because time-series span different time intervals and are partly populated with erroneous velocity estimates. In this study we build upon existing glacier velocity products from the GoLIVE data set (https://nsidc.org/data/golive) and compile a multi-temporal stack of velocity data over the Saint Elias Mountain range and vicinity. Each layer has a time separation of 32 days, making 5 it possible to observe details such as within-season velocity change over an area of roughly 150 000 km 2 . Our methodology is robust as it is based upon a fuzzy voting scheme applied in a discrete parameter space. In this way it is able to filter multiple outliers. The multi-temporal data stack is then smoothed to facilitate interpretation. This results in a spatio-temporal dataset where one can identify short-term glacier dynamics on a regional scale. The goal is not to improve accuracy or precision, but being able to extract the timing and location of ice flow events such as glacier surges. Our implementation is fully automatic 10 and the approach is independent of geographical area or satellite system used. We demonstrate this automatic method on a large glacier area in Alaska/Canada. Within the Saint Elias and Kluane mountain ranges, several surges and their propagation characteristics are identified and tracked through time, as well as more complicated dynamics in the Wrangell's mountains.Copyright statement. TEXT

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Section: Golive Velocity Fieldsmentioning

confidence: 99%