The file name states 4K and HDR; however, the camera used in the ISS HDEV module had no such capabilities. So, other versions of the video might exist, and indeed there are links to other versions further down.
The ISS module in question is the aluminium box below:
source:
x.com/Space_Station/status/603972721073102848/photo/3
source:
https://upload.wikimedia.org/wikipe...x-High_Definition_Earth_Viewing_cameras_1.jpg
source:
x.com/hdevcam
It contained four cameras, two wake-facing (retrograde, aft), one nadir (Earthward), and one ram-facing (prograde, forward). The design employed four completely different cameras because one of the objectives of the mission was to test the endurance of off-the-shelf components in space:
source:
https://www.tandfonline.com/doi/full/10.1080/22797254.2017.1396880
source:
https://eol.jsc.nasa.gov/ESRS/HDEV/files/HDEV-Final-Report_20200715.pdf
The four camera models were (mission launch date was 18 April 2014):
- Hitachi HV-HD30 (RAM)
- Toshiba IK-HR1S (NADIR)
- Panasonic AGHMC150 (Wake)
- Sony FCB-EH4300 (Wake)
As the ISS travels eastwards and Perth is visible when the video starts, then the footage is not reversed; thus, the camera used was the Hitachi HV-HD30:
It was capable of recording 1080i or 720p, 50hz/60Hz, but it seems it was fixed at 720p by the HDEV team.
https://eol.jsc.nasa.gov/ESRS/HDEV/files/HDEV-Final-Report_20200715.pdf
https://www.yumpu.com/en/document/read/19219308/hv-hd30-op-manual-computer-modules-inc
Because the Hitachi camera had no HDR (High Dynamic Range) capability, then in order to show the Earth's surface illuminated by the Sun, and at the same time the layer of atmosphere and the background stars, the frames had to be extracted from the original stream, the features above the horizon had to be enhanced to bring out detail and the stars, and then the enhanced frames were combined with the original frame to form a single HDR frame. Repeating the process for the entire footage created the HDR version. The footage was also upscaled to 4K.
Links to the SDR (Standard Dynamic Range) versions are available below. The 2K versions (1080p) are possibly the closest to the original stream, as the camera recorded footage in SDR and HD (720p):
4K SDR, HEVC codec (344MB):
https://sylvan.apple.com/Aerials/2x...LIA_v35_SDR_PS_FINAL_20180731_SDR_4K_HEVC.mov
2K SDR, HEVC codec (174MB):
https://sylvan.apple.com/Aerials/2x...LIA_v35_SDR_PS_FINAL_20180731_SDR_2K_HEVC.mov
2K SDR, AVC codec (262MB):
https://sylvan.apple.com/Videos/com...ALIA_v35_SDR_PS_FINAL_20180731_SDR_2K_AVC.mov
All three versions above also have the glitch. What they share in common is the original stream, the upscaling algorithm, any polishing, effects, and the AVC/HEVC codecs. "PS" in the file names might be a reference to Photoshop, which may have been used for automatic batch processing the frames (automatic upscaling, polishing, panning, cropping...).
Also, during the footage, the distance from the horizon to the upper edge of the sensor diminishes over time. However, the camera had no tilting capability, requiring the entire ISS to be slowly rolling for the effect to be physically produced. Thus, it is possible the method used for producing the enhanced footage included some virtual panning for cinematographic effect, causing the starfield to drift in an apparent direction and rate that was not the original direction of motion and speed (although the panning takes almost 6 minutes to complete):
External Quote:
The HDEV system was designed to have the cameras fixed in location, viewing angle, and in camera and lens settings. This design required no pan or tilt mechanisms, no zoom and no iris adjustments.
(...)HDEV was on a fixed mount and the cameras could not move. As a result many features passing just outside of the field of view could not be captured.
source:
https://eol.jsc.nasa.gov/ESRS/HDEV/files/HDEV-Final-Report_20200715.pdf
For information only, this glitch looks similar to the stabilisation glitch in the Wyoming UFO thread
https://www.metabunk.org/threads/wyoming-ufo.13386/
Source: https://www.facebook.com/watch/?v=983715570274466
It was solved in
post #22, and identified as a consequence of having stabilisation switched on whilst operating the camera on a tripod, which is a well known no no in photography. However, in the HDEV case, the camera had no stabilisation feature and the effect is selective and limited to one cycle.
Source: https://youtu.be/OE03oloNUe4