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NAME

i.modis.qc - Extract quality control parameters from Modis QC layers

KEYWORDS

QC, Quality Control, surface reflectance, Modis

SYNOPSIS

i.modis.qc
i.modis.qc help
i.modis.qc productname=string qcname=string input=name [band=integer] output=name [--overwrite] [--verbose] [--quiet]

Flags:

--overwrite
Allow output files to overwrite existing files
--verbose
Verbose module output
--quiet
Quiet module output

Parameters:

productname=string
Name of MODIS product type
Default: mod09Q1
qcname=string
Name of QC type to extract:adjcorr;mod09: Adjacency Correction;atcorr;mod09: Atmospheric Correction;cloud;mod09: Cloud State;data_quality;mod09: Band-Wise Data Quality Flag;diff_orbit_from_500m;mod09: 250m Band is at Different Orbit than 500m;modland_qa_bits;mod09: MODIS Land General Quality Assessment;mandatory_qa_11A1;mod11A1: MODIS Land General Quality Assessment;data_quality_flag_11A1;mod11A1: Detailed Quality Indications;emis_error_11A1;mod11A1: Average Emissivity Error Classes;lst_error_11A1;mod11A1: Average LST Error Classes;data_quality_flag_11A2;mod11A2: Detailed Quality Indications;emis_error_11A2;mod11A2: Average Emissivity Error Classes;mandatory_qa_11A2;mod11A2: MODIS Land General Quality Assessment;lst_error_11A2;mod11A2: Average LST Error Classes;aerosol_quantity;mod09A1s: StateQA Internal Snow Maskbrdf_correction_performed;mod09A1s: StateQA Internal Snow Maskcirrus_detected;mod09A1s: StateQA Internal Snow Maskcloud_shadow;mod09A1s: StateQA Internal Snow Maskcloud_state;mod09A1s: StateQA Internal Snow Maskinternal_cloud_algorithm;mod09A1s: StateQA Internal Snow Maskinternal_fire_algorithm;mod09A1s: StateQA Internal Snow Maskinternal_snow_mask;mod09A1s: StateQA Internal Snow Maskland_water;mod09A1s: StateQA Internal Snow Maskmod35_snow_ice;mod09A1s: StateQA Internal Snow Maskpixel_adjacent_to_cloud;mod09A1s: StateQA Internal Snow Mask
Default: modland_qa_bits
input=name
Name of the surface reflectance QC layer [bit array]
band=integer
Band number of Modis product mod09Q1=[1,2],mod09A1=[1-7]
output=name
Name of the output QC type classification layer
Default: qc

DESCRIPTION

i.modis.qc Extracts Requested Quality Assessment flags from the following Modis products: MOD09A1, MOD09Q1 and MOD11A2. This does include MOD09A1 QA_state_500m layer (see Notes).
MOD09A1/Q1: MODLAND QA Bits. bits=[0-1]
MOD09Q1: Cloud State. bits=[2-3] 
MOD09Q1: Band-wise Data Quality 250m bits=[4-7][8-11]
MOD09A1: Band-wise Data Quality 500m bits=[2-5][6-9][10-13][14-17][18-21][22-25][26-29]
MOD09A1/Q1: Atmospheric correction bit=[12]/[30]
MOD09A1/Q1: Adjacency correction bit=[13]/[31]
MOD09Q1: Different orbit from 500m product, bit=[14]
MOD11A2: Mandatory QA Flags bits=[0-1]
MOD11A1: Data Quality Flag bits=[2-3]
MOD11A1: Emis Error Flag bits=[4-5]
MOD11A1: LST Error Flag bits=[6-7]

MOD11A2: Mandatory QA Flags bits=[0-1]
MOD11A2: Data Quality Flag bits=[2-3]
MOD11A2: Emis Error Flag bits=[4-5]
MOD11A2: LST Error Flag bits=[6-7]
MOD09A1s: Cloud State bits=[0-1]
MOD09A1s: Cloud shadow bits=[2]
MOD09A1s: Land/Water Flag bits=[3-5]
MOD09A1s: Aerosol Quantity bits=[6-7]
MOD09A1s: Cirrus detected bits=[8-9]
MOD09A1s: Internal Cloud Algorithm Flag bits=[10]
MOD09A1s: Internal Fire Algorithm Flag bits=[11]
MOD09A1s: MOD35 snow/ice flag bits=[12]
MOD09A1s: Pixel adjacent to cloud bits=[13]
MOD09A1s: BRDF correction performed bits=[14]
MOD09A1s: Internal Snow Mask bits=[15]

NOTES

In MOD09A1: It seems that cloud related info is not filled properly in the standard QC (MOD09A1 in this module) since version 3, State-QA 500m images (MOD09A1s in this module) should be used (see Vermote et al., 2008).

TODO

Add one Day products.

SEE ALSO


MODIS Products

Vermote E.F., Kotchenova S.Y., Ray J.P.
MODIS Surface Reflectance User's Guide.
Version 1.2. June 2008.
MODIS Land Surface Reflectance Science Computing Facility.
Homepage
i.vi

AUTHORS

Yann Chemin

Last changed: $Date: 2010-12-23 16:55:38 -0800 (Thu, 23 Dec 2010) $


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