OpNom: TBDExperiment Overview
The Cloud-Aerosol Transport System (CATS) investigation uses a remote sensing, light detection and ranging (LiDAR), instrument designed to provide measurements of the particulate contents within the atmosphere including clouds and aerosols. The CATS instrument uses a laser to provide data on the location, composition and distribution of atmospheric constituents which impact the climate on a global scale. Obtaining a better understanding of cloud and aerosol coverage and properties is critical for understanding and modeling of the Earth system and associated climate feedback processes.Principal Investigator(s)
Goddard Space Flight Center, Greenbelt, MD, United States
National Aeronautics and Space Administration (NASA)Sponsoring Organization
Science Mission Directorate (SMD)Research Benefits
Information PendingISS Expedition Duration
March 2014 - September 2014Expeditions Assigned
39/40Previous ISS Missions
The Cloud-Aerosol Transport System (CATS) investigation uses a Lidar remote sensing instrument designed to provide measurements of atmospheric clouds and aerosols. The impact of clouds and aerosols (e.g., pollution, dust, smoke) on a global scale with regards to energy balance and climate feedback mechanisms is not yet fully understood. A better understanding of cloud and aerosol coverage and properties is critical for understanding of the Earth system and its associated climate feedback processes. The CATS LiDAR obtains range-resolved information which can be used to assess the climate impacts of clouds and aerosols on a global scale. The orbit of the International Space Station (ISS) is particularly suited to measurements of this kind, because the ISS passes over and along many of the primary aerosol transport paths within the atmosphere. The ISS orbit also permits study of diurnal (day to night) changes due to the effects of aerosols and clouds in the atmosphere – something other Earth Science satellite cannot readily obtain given their orbits.Description
The Cloud-Aerosol Transport System (CATS) is a LiDAR remote sensing instrument designed to provide range-resolved profile measurements of atmospheric aerosols and clouds. The CATS instrument uses a high repetition rate laser operating at three wavelengths (1064, 532, and 355 nm) to derive properties of cloud and aerosol layers including: layer height, layer thickness, optical depth, extinction, and depolarization-based discrimination of particle type. The CATS investigation is designed to provide a combination of long-term operational science, in-space technology demonstration, and technology risk reduction for future Earth Science missions; all the while adding to the continuous history of Earth atmospheric observations.
CATS is installed on the JEM-EF to enable nadir pointing of the science package sensors and instrumentation. Once CATS is connected to the JEM-EF, it will be activated via the ISS command and data handling system. Mission planning and coordination for CATS will be done via the NASA TReK system and the Marshall Space Flight Center Payload Operations Integration Center (MSFC POIC). The CATS investigation is designed to operate on the JEM-EF for at least 6 months and a maximum of 3 years.
Any investigation that helps researchers, scientist and engineers better understand the makeup, structure and evolution of the atmosphere has the potential to enhance spacecraft launch, landing and communications in the future. Therefore, CATS provides another data set, from a unique vantage point from which the community will eventually be able to draw knowledge and an understanding of Earth’s remarkable and changing atmosphere.Earth Applications
The CATS investigation is intended to perform long duration observations of up to 3 years beginning in 2014, providing continuity in data observations that began with the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO). Such long term observations of Earth’s changing atmosphere are needed to thoroughly understand formative and ongoing processes and ultimately help researchers model and predict future changes. Information on cloud and aerosol coverage and properties is therefore critical for understanding of the Earth system and its associated climate feedback processes.
The CATS instrumentation requires an external nadir viewing location on ISS. Power and data handling is needed to operate the investigation over long periods of time (CATS is a remote sensing instrument intended to operate continuously on-orbit, with data streaming through the Medium Rate Data Link (MRDL) interface). CATS requires no crew involvement after SSRMS installation is completed.Operational Protocols
When on-orbit, CATS is intended for continuous, or near-continuous, operation. The investigation is commanded on and will operate continuously, flowing data down through the Medium Rate Data Link (MRDL) user interface to a ground processing station at Goddard Space Flight Center (GSFC). For safety purposes the investigation (e.g., the laser) will be disabled during EVA and docking events.
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McGill , Hlavka DL, Scott VS, Spinhirne , Hart WD, Schmid . Cloud Physics Lidar: instrument description and initial measurement results. Applied Optics. 2002 Jun 20; 41(18): 3725-3734. DOI: 10.1364/AO.41.003725.
McGill , Hlavka DL, Vaughan MA, Trepte CR, Hart WD, Winker DM, Keuhn R. Airborne validation of spatial properties measured by the CALIPSO lidar. Journal Of Geophysical Research. 2007 October 17; 112(D20): 27. DOI: 10.1029/2007JD008768.