Until the arrival of CloudSat, satellites studying the atmosphere could show the surface of clouds, but only gave a 2D picture of cloud cover. Thickness data - which would help in determining cloud volume and water, snow or ice quantity - was not available. CloudSat is collecting new data to improve knowledge of clouds and their role in the climate. The satellite was developed by NASA jointly with the Canadian Space Agency.
CloudSat is carrying out the first global three-dimensional study of clouds. It collects data on their structure, frequency and volume and is improving understanding of their influence on the weather. To do this, CloudSat uses a hyperfrequency radar device to probe the cloud cover and then compile information on cloud thickness, altitudes at the base and summit of the clouds and even the amount of water and ice they contain.
Finally, CloudSat will improve and validate the data collected by other satellites studying the atmosphere and clouds.
A constellation of satellites
CloudSat is part of a constellation of scientific research satellites. This constellation, called the A-Train, is currently composed of the satellites Aqua, Aura, CALIPSO and CloudSat.
CALIPSO is a joint Franco-American mission. The satellite is collecting information on the influence of thin transparent clouds and aerosols on solar energy transfer in the atmosphere. The Aqua satellite is carrying numerous instruments for collecting data on the Earth's atmosphere. Aqua is the lead spacecraft in the formation.