THE CLOUDSAT MISSION AND THE A-TRAIN Stephens, Graeme L.; Vane, Deborah G.; Boain, Ronald J. ...
Bulletin of the American Meteorological Society,
12/2002, Volume:
83, Issue:
12
Journal Article
Peer reviewed
CloudSat is a satellite experiment designed to measure the vertical structure of clouds from space. The expected launch of CloudSat is planned for 2004, and once launched, CloudSat will orbit in ...formation as part of a constellation of satellites (the A-Train) that includes NASA'sAquaandAurasatellites, a NASA–CNES lidar satellite (CALIPSO), and a CNES satellite carrying a polarimeter (PARASOL). A unique feature that CloudSat brings to this constellation is the ability to fly a precise orbit enabling the fields of view of the CloudSat radar to be overlapped with the CALIPSO lidar footprint and the other measurements of the constellation. The precision and near simultaneity of this overlap creates a unique multisatellite observing system for studying the atmospheric processes essential to the hydrological cycle.
The vertical profiles of cloud properties provided by CloudSat on the global scale fill a critical gap in the investigation of feedback mechanisms linking clouds to climate. Measuring these profiles requires a combination of active and passive instruments, and this will be achieved by combining the radar data of CloudSat with data from other active and passive sensors of the constellation. This paper describes the underpinning science and general overview of the mission, provides some idea of the expected products and anticipated application of these products, and the potential capability of the A-Train for cloud observations. Notably, the CloudSat mission is expected to stimulate new areas of research on clouds. The mission also provides an important opportunity to demonstrate active sensor technology for future scientific and tactical applications. The CloudSat mission is a partnership between NASA's JPL, the Canadian Space Agency, Colorado State University, the U.S. Air Force, and the U.S. Department of Energy.
Numerous books, articles, and technical papers have been written on system engineering's role in successful project management. Components of the project development life cycle such as the definition ...and analysis of requirements, the design process, configuration control, and risk management are frequently identified as key ingredients to the successful outcome of any endeavor. This is true for deployment of a product or system and also for rollout of an important service. Most of the literature focuses on what the major system engineering steps are without necessarily addressing how to complete each step or how to successfully transition between them. Over the past three years the CloudSat Project, a NASA Earth System Science Pathfinder mission to provide from space the first global survey of cloud profiles and cloud physical properties, has implemented a successful project system engineering approach. Techniques learned through heuristic reasoning of past project events and professional experience were applied along with select methods recently touted to increase effectiveness without compromising efficiency. The use of an online database as the single repository for officially identified requirements and completing a streamlined system‐level fault tree analysis and accompanying probabilistic risk assessment are some specific examples. The collective set has allowed the CloudSat Project to be successful through formulation, approval, and at least early implementation phase.
