On August 18, after a 42-day journey from the California Institute of Technology campus in Pasadena, CA, USA, the first of the OCO mission's Fourier transform spectrometer (FTS) mobile laboratories arrived in Darwin, Australia. This mobile laboratory installation is located at the Tropical Western Pacific (TWP) facility managed by the Department of Energy's Atmospheric Radiation Monitoring (ARM) program. By the end of August, the FTS mobile laboratory successfully demonstrated autonomous operation capabilities and can now be controlled by the OCO Science Team from Pasadena.
The Darwin FTS is one of several deployed worldwide that the OCO mission will use to check or "validate" the accuracy of data acquired by the space-based Observatory. This validation procedure is essential to ensure that the CO2 source and sink information derived from OCO space-based data is as accurate as possible. Installation of the FTS mobile laboratories well in advance of the OCO launch enables the Science Team to establish a record of the CO2 variations over each validation site.
The OCO Science Team will begin to use the Darwin facility to measure the atmospheric column abundance of CO2 in the fall of 2005. Once the facility is operational, the team will carefully check atmospheric chemistry measurements that they retrieve from the FTS against other measures of atmospheric content acquired at the same time and location.
These checks will ensure that the FTS records very precise measures of the CO2 abundance. The ultimate goal is to use the FTS measurements from Darwin and other locations to validate the precision of the data acquired by the space-based OCO instrument.