By the middle of 1995, NGDC had advanced their algorithms to include use of the thermal band to identify cloud-free image areas and larger numbers of orbital passes. The result was a capability to filter out noise and ephemeral events like fires and lightning to produce a "stable lights" dataset, with units reported in percent frequency of detection within the set of cloud-free observations. NGDC made a stable lights dataset of the USA using 236 orbits of nighttime DMSP data from the dark half of lunar cycles from a six month time period.

Reference: Elvidge, C.D., Baugh, K.E., Kihn, E.A., Kroehl, H.W, Davis, E.R, 1997, Mapping of city lights using DMSP Operational Linescan System data. Photogrammetric Engineering and Remote Sensing, v. 63, p. 727-734.

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