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Flexi 12 cloud masking
Flexi 12 cloud masking




  1. Flexi 12 cloud masking archive#
  2. Flexi 12 cloud masking series#

First, clouds play a critical role in the radiative balance of the Earth and must be accurately described to assess climate and potential climate change. In addition to the MOD02 calibrated radiances, a 1-km land/water mask, DEM, ecosystem analysis, snow/ice cover map, NCEP analysis of surface temperature and wind speed, and an estimate of precipitable water are required as inputs.Ī determination of the presence of global cloudiness is essential to the MODIS mission for two reasons. Thresholds vary with surface type, atmospheric conditions (moisture, aerosol, etc.), and viewing geometry. The spectral tests rely on radiance (temperature) thresholds in the infrared and reflectance thresholds in the visible and near-infrared. For inconclusive results, spatial- and temporal-variability tests are applied. From these, a clear-sky confidence level (high confident clear, probably clear, undecided, cloudy) is assigned to each FOV.

Flexi 12 cloud masking archive#

The MODIS cloud mask algorithm employs a battery of spectral tests, which use methodology applied in the AVHRR Processing scheme Over cLoudy Land and Ocean (APOLLO), International Satellite Cloud Climatology Project (ISCCP), CLoud Advanced Very high resolution Radiometer (CLAVR), and the Support of Environmental Requirements for Cloud Analysis and Archive (SERCAA) algorithms to identify cloudy FOVs. There are two MODIS Cloud Mask data product files: MOD35_L2, containing data collected from the Terra platform and MYD35_L2, containing data collected from the Aqua platform. Radiometrically-accurate radiances are required, thus holes in the Cloud Mask will appear wherever the input radiances are incomplete or of poor quality assurance.

flexi 12 cloud masking

The 250-m cloud mask flags are based on visible channel data only. An indication of shadows affecting the scene is also provided.

Flexi 12 cloud masking series#

The algorithm employs a series of visible and infrared threshold and consistency tests to specify confidence that an unobstructed view of the Earth's surface has been observed. The MODIS Cloud Mask product is a Level-2 product generated at 1-km and 250-m (at nadir) spatial resolutions.






Flexi 12 cloud masking