ATSR-GRAPE Description

Measurements

ATSR / AATSR

Local Observation Time and Length of Data Record

10:00 AM ; 1999-2002 (ERS), 2003-2009 (Envisat)

Spatial Resolution

1 km (detection), 4 km (retrieval)

Cloud Detection

VIS/NIR/IR optimal estimation.

Retrieval Methodology

COD, CP, CRE, phase -> CT, CWP.
Cloud pressure, cloud optical depth, and effective particle radius are retrieved only during day, using an Optimal Estimation approach on the five available VIS / NIR / IR channels (0.7, 0.9, 1.6, 11, and 12 μm). Cloud water path is derived from optical depth and effective particle radius.

Ancillary input

ECMWF profiles (operational) and particle model.

References

Sayer, A. M., C. A. Poulsen, C. Arnold, E. Campmany, S. Dean, G. B. L. Ewen, R. G. Grainger, B. N. Lawrence, R. Siddans, G. E. Thomas, and P. D. Watts, 2011: Global retrieval of ATSR cloud parameters and evaluation (GRAPE): dataset assessment. Atmos. Chem. Phys., 11, 3913-3936.