During the last four years of the CyMISS (Tropical Cyclone Intensity Measurements from the ISS) program, our team has acquired image sequences of several dozen powerful hurricanes, typhoons and tropical cyclones scattered across the globe. While 2018 proved to be a busy hurricane season in the Atlantic, it also saw a number of powerful tropical cyclones in the southern hemisphere earlier in the year. One of these storms was Tropical Cyclone Gita which was observed by the crew of the ISS in support of CyMISS during overpasses on February 13 and 14, 2018. The individual photographs from the original 240-image sequence from the February 13 overpass were remapped to approximate an overhead view before they were stitched together into a synoptic color mosaic covering an area of 1,200 by 800 kilometers shown below. Notice that the cloud bands of this southern hemisphere storm display a clockwise rotation – the opposite of its northern hemisphere kin. A high-resolution version of this synoptic mosaic with an image scale of 500 meters/pixel can be viewed by clicking on the image below (for more information on this overpass, see “CyMISS Image of the Month: Tropical Cyclone Gita”).
This mosaic shows Tropical Cyclone Gita as viewed from the ISS on February 13, 2018. It was created by remapping the original 240 photographs taken by the crew of the ISS to approximate an overhead view before stitching them together and covers an area of 1,200 by 800 kilometers. Click on the image to view a high resolution version with a scale of 500 meters/pixel. (A.J. LePage/Visidyne/JSC-NASA)
February’s Image of the Month is a closeup 3D view of the eye Tropical Cyclone Gita created using images from a sequence of 240 photographs taken by the crew of the ISS during the February 14 overpass. When the four-minute photography session started at 19:55:00 GMT, Gita was located at about 21.5° S, 174.9° E in the South Pacific and was rated as a strong Category 3 storm with sustained winds of about 193 kph (120 mph). As was done with the earlier overpass images, the individual photographs from the original 240-image sequence were remapped to approximate an overhead view before they were stitched together into a synoptic color mosaic covering an area of 1,500 by 1,000 kilometers. A high-resolution version of this synoptic mosaic with an image scale of 500 meters/pixel can be viewed by clicking on the image below.
This synoptic image shows Tropical Cyclone Gita as viewed from the ISS on February 14, 2018 at about 19:57 GMT in the South Pacific. Covering an area of 1,500 by 1,000 km, this mosaic was created by remapping the original sequence of color photographs taken by the crew of the ISS to approximate an overhead view before stitching them together. Click on the image to view a high-resolution version with a scale of 500 meters/pixel. (A.J. LePage/Visidyne/NASA-JSC)
The Image of the Month is a 3D image created using a pair of close up photographs of the enormous 125-kilometer eye of Tropical Cyclone Gita taken a few seconds apart around 19:57:18 GMT. Only the red channel of the original color images was used in order to cut through any atmospheric haze and maximize the visibility of the cloud features. These images were remapped to approximate an overhead view before being combined to create an anaglyphic 3D image (a pair of stereo glasses with a red filter over the left eye and a blue filter on the right is required to reproduce the 3D effect). The resulting stereo view, which can be seen at full size with a scale of 100 meters/pixel by clicking on the image below, covers an area of 300 by 200 kilometers and clearly reveals a lot of complex structure in and around the eye of this storm.
This is a close up anaglyphic 3D view (left eye red, right eye blue) of the eye of Tropical Cyclone Gita as it appeared from the ISS at about 19:57:18 GMT on February 14, 2018. It was created by combining a pair of red-filtered images taken a few seconds apart which had been processed to approximate a common overhead view covering an area of 300 by 200 kilometers. Click on the image to view the full size version at a scale of 100 meters/pixel. (A.J. LePage/Visidyne/JSC-NASA)
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, to support the development of an improved remote sensing method to determine more accurately the strength of these destructive storms using stereoscopy. 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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See earlier articles on the CyMISS program here.