The goal of the ongoing CyMISS (tropical Cyclone intensity Measurements from the ISS) project is to acquire image sequences of intense tropical cyclones (TCs), such as hurricanes and typhoons, to support the development of an improved remote sensing method to determine more accurately the strength of these destructive storms using stereoscopy. Funded by CASIS (Center for the Advancement of Science in Space) which manages the ISS US National Laboratory for NASA, this project has amassed a large collection of storm images during the last four years that we wish to share. One of the first TCs observed by the crew of the ISS for CyMISS using a photography protocol specifically designed to aid in the generation of stereo images was Super Typhoon Soudelor in August 2015 (see “New Tropical Cyclone Observations from the ISS”).
The crew of ISS Expedition 44 acquired a sequence of 311 images as part of a 5 minute, 11 second photography session starting at 07:58:48 GMT on August 4, 2015. A subset of the first 231 images from this sequence running to 08:02:38 GMT can be viewed in the video above. Typhoon Soudelor formed on July 29, 2015 in the Pacific Ocean and moved westward towards Asia. It quickly intensified and by August 3 was a “super typhoon” rated at Category 5 on the Saffir-Simpson scale. By the time the crew of the ISS photographed Soudelor in support of our project, it had been downgraded to a Category 4 storm. A closeup of the 40-kilometer wide eye of Typhoon Soudelor as it appeared at 08:00:44 GMT is shown below. Created from ISS044-E-29006 with an effective pixel footprint of 120 by 260 meters, it has been reprojected to approximate an overhead view using only the red channel of the image to reduce the effects of atmospheric scattering and maximize the visibility of cloud features.
A red-channel close up view of the eye of Typhoon Soudelor from 08:00:44 GMT on August 4, 2015. This image has been reprojected to approximate an overhead view and covers an area of 150×100 kilometers. Click on image to see the full-resolution version. (A.J. LePage/Visidyne/NASA-JSC)
April’s Image of the Month is a 3D view of Typhoon Soudelor created using a subset of 266 images acquired by the ISS crew. In order to create this anaglyphic 3D image (left eye red, right eye blue), the individual photographs from the original image sequence were remapped to approximate an overhead view before various parts of the frames were stitched together into a synoptic 3D mosaic covering an area of approximately 1,960 by 860 kilometers. A high resolution version of this synoptic 3D mosaic with an image scale of 500 meters/pixel can be viewed by clicking on the image below.
This is an anaglyphic 3D mosaic (left eye red, right eye blue) of Typhoon Soudelor as seen from the ISS at about 08:01 GMT on August 4, 2015 It was created by combining various parts of a subset of 266 images which have been processed to approximate a common overhead view covering an area of about 1,960×860 kilometers. Click on the image to view the full-size version at a scale of 500 meters/pixel. (A.J. LePage/Visidyne/JSC-NASA)
Given that this was the first image sequence acquired by the crew of the ISS using our photography protocol, early on I was eager to experiment with the creation of 3D images using a variety of processing methods. As a bonus, below is another anaglyphic stereo image I produced using a pair of images acquired towards the end of the image sequence as the view moved beyond the edge of Typhoon Soudelor. In the lower left corner of the image are the outer bands of Soudelor with spectacular stereo view of clouds over the Pacific Ocean looking out towards the horizon including a group of towering cumulus clouds of a thunderstorm just above the center.
This is a bonus anaglyphic 3D image (left eye red, right eye blue) showing the outer edge of Typhoon Soudelor and cloud formations over the Pacific stretching beyond towards the horizon. (A.J. LePage/Visidyne/JSC-NASA)
The CyMISS team at Visidyne would like to thank the crew of the ISS as well as the staff at NASA’s Marshall Space Flight Center and Johnson Space Center for their ongoing efforts. The original images are courtesy of the Earth Science and Remote Sensing Unit at NASA Johnson Space Center. The work presented here is supported in part under CASIS Grant UA-2019-013.
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Related Reading
See earlier articles on the CyMISS program here.