Structure-From-Motion Photogrammetry of Antarctic Historical Aerial Photographs in Conjunction with Ground Control Derived from Satellite Data

Abstract

A longer temporal scale of Antarctic observations is vital to better understanding glacier dynamics and improving ice sheet model projections. One underutilized data source that expands the temporal scale is aerial photography, specifically imagery collected prior to 1990. However, processing Antarctic historical aerial imagery using modern photogrammetry software is difficult, as it requires precise information about the data collection process and extensive in situ ground control is required. Often, the necessary orientation metadata for older aerial imagery is lost and in situ data collection in regions like Antarctica is extremely difficult to obtain, limiting the use of traditional photogrammetric methods. Here, we test an alternative methodology to generate elevations from historical Antarctic aerial imagery. Instead of relying on pre-existing ground control, we use structure-from-motion photogrammetry techniques to process the imagery with manually derived ground control from high-resolution satellite imagery. This case study is based on vertical aerial image sets collected over Byrd Glacier, East Antarctica in December 1978 and January 1979. Our results are the oldest, highest resolution digital elevation models (DEMs) ever generated for an Antarctic glacier. We use these DEMs to estimate glacier dynamics and show that surface elevation of Byrd Glacier has been constant for the past ∼40 years.

57-Year Ice Velocity Dynamics in Byrd Glacier Based on Multisource Remote Sensing Data

“…On December 6, 1978, and January 31, 1979, two sets of aerial photographs were obtained by Brecher [25] for photogrammetric processing, and the total displacements of 601 points (470 on the glacier) were measured to estimate the ice velocity of the glacier. Child et al [8] regenerated two DEMs using aerial datasets to produce an ice velocity map by tracking the surface slope patterns and found that the velocity values along the main track agreed well with those obtained by Brecher [25]. Hughes and Fastook [53] obtained similar results in their field survey.…”

“…Additionally, from the diagnostic modeling experiments, the change in buttressing from the regions near the calving fronts of the RIS showed insignificant influence (~1%) on the grounding-line ice velocity of Byrd Glacier [59]. According to satellite observations and hydrostatic equilibrium calculations based on DEMs, little to no change in the grounding zone of Byrd Glacier has occurred over the last 40 years, indicating its steady state [8], [60]. Temperature in the Marilyn AWS was just above freezing point within a few hours during the austral summer, suggesting a low chance of sustained surface melting in summer for Byrd Glacier.…”

“…The ice velocity of glaciers is not only an important parameter for estimating the mass balance (MB) of the Antarctic Ice Sheet (AIS) using the input-output method but can also be used to monitor the spatiotemporal ice dynamics of glaciers and increase the understanding of the driving forces behind ice velocity change [1], [5]- [7]. Unfortunately, several glaciers still lack sufficient velocity analyses, especially in East Antarctica [1], and most studies on glacier ice flow have focused only from the 1990s to the present [8], resulting in an incomplete understanding of long-term glacier dynamics.…”

Semantic Segmentation of Historical Photographs of the Antarctica Peninsula

“…Note that these images are not georeferenced. This archive has not yet been used for semantic segmentation but only for small scale point cloud reconstructions, as done by Child et al (2020) or Kunz et al (2012).…”

85 years of snowfall-driven ice sheet change in East Antarctica

“…Since the beginning of the 20 th century, several expeditions were launched to Antarctica with the aim of exploring and capturing aerial images for the production of geographical maps [17][18][19][20][21] . However, just a handful of studies have previously used this data for generating digital elevation models (DEMs) and only for glaciers located in West Antarctica and the Antarctic Peninsula 10,22,23 , going back to 1947 23 . On the Antarctic Peninsula, these observations show widespread…”