A comparison was made between cloud masks obtained from two algorithms : (1) radiometric camera-by-camera cloud mask (RCCM) and stereoscopically-derived cloud mask (SDCM). The cloud mask data archived for each algorithm differ slightly according to the table below:

radiometric camera-by-camera cloud mask (RCCM) 0 no retrieval 1 cloud with high confidence 2 cloud with low confidence 3 clear with low confidence 4 clear with high confidence

stereoscopically-derived cloud mask (SDCM) 0 no retrieval 1 cloud with high confidence 2 cloud with low confidence 3 near surface clouds 4 clear

The comparisons shown here attempt to maximize the data available for comparison. RCCM retrievals of (1-2) are considered "cloudy", retrievals of (3-4) are considered "clear". SDCM retrievals of (1-3) are considered "cloudy"; retrievals of (4) are considered "clear". Retrievals from the RCCM and SDCM algorithm are compared to determine if they agree in their interepretation of the pixel scene.

The RCCM and SDCM algorithms agree in 77.3% of cases and disagree in 22.7% of all retrievals for June, 2002

An inventory of the fraction of time these algorithms disagree is shown below. Disagreement statistics were computed for all MISR data available for June, 2002.

A second inventory maximizing the quality of the data available for comparison is shown below. RCCM retrievals of (1) are considered "cloudy", retrievals of (4) are considered "clear". SDCM retrievals of (1) are considered "cloudy"; retrievals of (4) are considered "clear". "High confidence retrievals from the RCCM and SDCM algorithm are compared to determine their agreement in interepreting the pixel scene.

The RCCM and SDCM algorithms agree in 71.3% of cases and disagree in 28.7% of all retrievals for June, 2002

An inventory of the fraction of time these algorithms disagree is shown below. Disagreement statistics were computed for all MISR data available for June, 2002.

MISR cloud mask frequencies for June, 2002 for the RCCM and SDCM algorithms are shown below.