It has been quite a while since I have shared an update here on my ongoing project to photograph tropical cyclones from the International Space Station (ISS). Called CyMISS (tropical Cyclone intensity Measurements from the ISS), the goal of this project is to acquire image sequences of tropical cyclone to support the development of an improved method to determine more accurately the strength of powerful tropical cyclones like hurricanes using stereoscopy. With a new grant secured from CASIS (Center for the Advancement of Science in Space) which manages the ISS US National Laboratory for NASA, this work will continue until at least the spring of 2018.
With the recent hurricane activity in and around the US, the crew of the ISS has used our project’s photography protocol on numerous occasions to observe hurricanes like Harvey and Irma which each left a path of devastation in their wakes. In the case of Hurricane Harvey, we were lucky to get the observation sequence we requested with only 19 hours notice (instead of the normal 48 hours) as the rapidly intensifying storm was bearing down on the Johnson Space Center (JSC) in Houston. It would be over a week, however, before the data were available from the JSC due to the historic flooding caused by Harvey. As soon as JSC recovered, we were able to request and secure photographs from the ISS for separate overpasses of Hurricane Irma on September 5, 7 and 10.
I have been slowly working through a backlog of photography and have created some sample images of these historic storms. The feature illustration at the top of this piece is one of those images. To create it, I processed a photograph acquired at 15:11:20 GMT on September 5, 2017 when Hurricane Irma was a Category 5 storm in the Atlantic Ocean still a few hundred kilometers east of the Lesser Antilles. The red channel of the image, where the visibility of scene features is maximized, had its contrast adjusted and was remapped to approximate an overhead view of the storm which covers an area of about 225 by 126 kilometers. The unprocessed color photograph from which this closeup is derived is shown below.
In addition to images such as these, I have also prepared some preliminary anaglyphic stereo views from selected overpasses as part of our data assessment process. Below is an excerpt from the ISS program’s Increment 53-54 Weekly Science Summary for Week 6 for the experiment officially designated “NASA’s CEO Tropical Cyclone Experiment” presenting some sample images and descriptions I provided to the ISS program office for this purpose. Don’t forget to grab your red/cyan (or red/blue) anaglyphic stereo glasses!
Weekly Science Summary – Tropical Cyclone
As has been noted, there has been a lot of activity recently and the Tropical Cyclone team is slowly working through our growing backlog of excellent ISS photography. However, we have been putting our focus recently on analyzing imagery of notable storms like Hurricanes Harvey and Irma. In the course of our analysis, we have created some anaglyphic stereo images (which require the red/cyan color glasses to view properly) which we are ready to share.
This is an anaglyphic stereo view (left eye red, right eye cyan) of Hurricane Harvey as it appeared at about 21:23 GMT (4:23 PM CDT) on August 25, 2017 as the eye of this Category 3 storm was approaching the Texas coast and intensifying. The crew of the ISS photographed Hurricane Irma in support of Visidyne’s ongoing CyMISS (tropical Cyclone intensity Measurements from the ISS) project whose goal is to develop a new remote sensing method to determine the strength of hurricanes more accurately. This stereo mosaic was created by analyzing a sequence of 240 digital color images acquired by the crew of the ISS over four minutes. The images were spatially remapped to approximate an overhead view and specially processed to extract their stereo content. This 1,500 by 750-kilometer (932 by 466 miles) stereo mosaic clearly illustrates the altitude differences between the high altitude clouds associated with Harvey and the lower altitude, puffy cumulus clouds especially prominent over land in the left half of this view.
This anaglyphic stereo image provides a close-up view of the 34-kilometer (21-mile) wide eye of Hurricane Harvey. This monochromatic (B&W) view was created by combining the red-channel (which helps to maximize the visibility of scene details) from a pair of processed color images taken from the ISS within a few seconds of 21:23:04 GMT (4:23:04 PM CDT) on August 25, 2017. The images were spatially remapped to approximate an overhead view which covers an area of about 150 by 100 kilometers (93 by 62 miles). This image provides a clear view into the eye of Harvey as the surface winds were at 200 kph (125 mph) and increasing as the rapidly intensifying storm approached the coast of Texas.
This is an anaglyphic stereo view of Hurricane Irma as it appeared from the ISS at about 13:58 GMT (9:58 AM EDT) on September 10, 2017 just as the eye of this Category 4 storm was passing over the Florida Keys. This stereo mosaic was created by analyzing a sequence of 361 digital color images acquired by the crew of the ISS over six minutes. The images were spatially remapped to approximate an overhead view and specially processed to extract their stereo content. This mosaic covers an area of about 2,000 by 1,200 kilometers (1,243 by 755 miles) and stretches from Alabama on the left southeast towards the Bahamas on the right with the ground track of the ISS running parallel to the top edge. Cuba, Florida and the other southeastern states are hidden beneath Irma’s clouds in the middle of the mosaic.
More to Come
These sample images are only the tip of a veritable iceberg of hurricane images yet to be shared in this forum. A more detailed update of the CyMISS tropical cyclone images from around the globe for 2016 and 2017 will follow in the near future.
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See earlier articles on the CyMISS program here.
Increment 53-54 Weekly Science Summary – Week 6, JSC/NASA, Released October 6, 2017