Table 1. Currently Available UV or Near-UV Reflectivity Data Sets

Years	Data Set	Description
1979-1992	Nimbus-7/TOMS (N7)	The 331 nm daily reflectivity is produced as part of standard processing using in-flight calibration. Full global coverage every day. Only a few missing days from1980 to 1992.
1985-2008	SBUV-2 Series (N-9, N-11, N-16, N-17, N-18)	The 331 nm daily reflectivity is produced as part of standard processing using in-flight calibration. There are 14 nadir-viewing orbits per day. Full global coverage once per week. Only a few missing days. Additional data are available from N-17 (2002) and N-18 (2005). Unlike N-16 (2000), N-17, and N-18, N-9 (1984), and N-11 (1998) have to be used with caution, since they have drifting orbits (changing equator crossing times).
1996-2006	Earth-Probe/TOMS (EP)	The new recalibrated 331 nm daily reflectivity is produced as part of standard processing. Full global coverage every day. Only a few missing days in 10 years. The calibration precision was improved by using N-16 as a reference but does not have the precision for trend computation.
1997-2008	SeaWiFS (SW)	The 412 nm reflectivity has been produced using the TOMS production algorithm and in-flight SeaWiFS calibration. The precision is very high. However, high latitude data (>60degrees) is limited to summer months. The plane of cross-track scanning is tilted 20degrees away from the sun to avoid ocean sun glint.
2004-2008	Ozone Monitoring Instrument (OMI)	The 331 nm daily reflectivity is produced as part of standard OMI processing using in-flight calibration. Full global coverage every day. Reflectivity values are available for all wavelengths from 330 nm to 500 nm. However, different detectors and calibrations in multiple focal planes currently make it difficult to relate 412 nm visible to 331 nm UV wavelengths with high precision.