NASA Tropical Rainfall Measuring Mission

The Tropical Rainfall Measuring Mission, or TRMM, is an ongoing collaborative effort between NASA and JAXA (the Japan Aerospace Exploration Agency). The purpose of this mission is to analyze tropical rainfall information in the hopes of gaining greater insight into the water cycles in the Earth's current climate system. By studying this information, scientists are able to better understand the effects of global warming, and more accurately predict future changes in the Earth's climates.

Mission data is collected by the TRMM satellite, which was launched in 1997, and remains in orbit. Once collected, all data is sent to Earth, where it must be validated via ground-based systems. This validation is performed by The NASA Tropical Rainfall Measuring Mission (TRMM) Satellite Validation Office at NASA Goddard Space Flight Center in Greenbelt, Maryland.Each day, every 6 - 10 minutes, several National Weather Service Doppler radars throughout the Unites States perform scans of rainfall data in their current areas. The radar data is received by the National Weather Service and sent to the National Climatic Data Center in Asheville, North Carolina. Next, it is sent to the TRMM Validation Office in Greenbelt, Maryland.At approximately 8 PM EST each day, the radar data is processed by an IDL program, which creates images out of the received radar scans. These images are then copied to a Linux server, where they are made available for online viewing.

"Given that each radar performs one scan every 6-10 minutes, 24 hours per day, the ability to animate these images is extremely important." says Program Manager David B. Wolff (Science Systems and Applications, Inc., Lanham, MD). This is where Automated Workflows was able to help. Using Apple Computer's AppleScript and QuickTime technologies, Automated Workflows developed a solution that will automatically convert each batch of radar images into an animation.Once the radar images for a given day have been copied to the Linux server, the server is now mounted on a Macintosh computer, and the "Build Image Sequence" AppleScript solution is triggered. The script determines the location of the images to process, launches QuickTime Pro, merges the images together, and saves the animation as a QuickTime movie, which is then made available to the world through a web link. "It would be impossible for us to view all of the images that we create. Animation is the only efficient means of doing so, and QT is the best approach since it's nearly-lossless compression is of high quality and low bandwidth." says David Wolff. "I used to make these movies manually, which was quite time consuming and laborious. Your script will make it possible for us to have QT movies available for all of our sites in near real-time. As far as I know", thanks to this AppleScript solution, "we will have the largest archive of daily radar animations available anywhere."