Provided by: grass-doc_7.0.3-1build1_all 
NAME
i.modis.qc - Extracts quality control parameters from MODIS QC layers.
KEYWORDS
imagery, imagery quality assessment, reflectance, land surface temperature, vegetation, MODIS
SYNOPSIS
i.modis.qc
i.modis.qc --help
i.modis.qc input=name output=name productname=string qcname=string [band=string] [--overwrite]
[--help] [--verbose] [--quiet] [--ui]
Flags:
--overwrite
Allow output files to overwrite existing files
--help
Print usage summary
--verbose
Verbose module output
--quiet
Quiet module output
--ui
Force launching GUI dialog
Parameters:
input=name [required]
Name of input surface reflectance QC layer [bit array]
output=name [required]
Name for output QC type classification layer
productname=string [required]
Name of MODIS product type
Options: mod09Q1, mod09A1, mod09A1s, mod09CMG, mod09CMGs, mod09CMGi, mod11A1, mod11A2, mod13A2,
mcd43B2, mcd43B2q
Default: mod13A2
mod09Q1: surf. refl. 250m 8-days
mod09A1: surf. refl. 500m 8-days
mod09A1s: surf. refl. 500m 8-days, State QA
mod09CMG: surf. refl. 5000m daily
mod09CMGs: surf. refl. 5000m daily, State QA
mod09CMGi: surf. refl. 5000m daily, Internal Climatology
mod11A1: LST 1km daily (Day/Night)
mod11A2: LST 1km 8-days (Day/Night)
mod13A2: VI 1km 16-days
mcd43B2: Brdf-Albedo Quality (Ancillary SDS) 1km 8-days
mcd43B2q: Brdf-Albedo Quality (BRDF SDS) 1km 8-days
qcname=string [required]
Name of QC type to extract
Options: adjcorr, atcorr, cloud, data_quality, diff_orbit_from_500m, modland_qa, mandatory_qa_11A1,
data_quality_flag_11A1, emis_error_11A1, lst_error_11A1, data_quality_flag_11A2, emis_error_11A2,
mandatory_qa_11A2, lst_error_11A2, aerosol_quantity, brdf_correction_performed, cirrus_detected,
cloud_shadow, cloud_state, internal_cloud_algorithm, internal_fire_algorithm, internal_snow_mask,
land_water, mod35_snow_ice, pixel_adjacent_to_cloud, icm_cloudy, icm_clear, icm_high_clouds,
icm_low_clouds, icm_snow, icm_fire, icm_sun_glint, icm_dust, icm_cloud_shadow,
icm_pixel_is_adjacent_to_cloud, icm_cirrus, icm_pan_flag, icm_criteria_for_aerosol_retrieval,
icm_aot_has_clim_val, modland_qa, vi_usefulness, aerosol_quantity, pixel_adjacent_to_cloud,
brdf_correction_performed, mixed_clouds, land_water, possible_snow_ice, possible_shadow, platform,
land_water, sun_z_angle_at_local_noon, brdf_correction_performed
Default: modland_qa
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: mod13A2: 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: mod13A2: Quantity range of Aerosol
brdf_correction_performed: mcd43B2q: Quality of BRDF correction performed
cirrus_detected: mod09*s: StateQA Cirrus Detected
cloud_shadow: mod09*s: StateQA Cloud Shadow
cloud_state: mod09*s: StateQA Cloud State
internal_cloud_algorithm: mod09*s: StateQA Internal Cloud Algorithm
internal_fire_algorithm: mod09*s: StateQA Internal Fire Algorithm
internal_snow_mask: mod09*s: StateQA Internal Snow Mask
land_water: mcd43B2: Quality of BRDF correction performed
mod35_snow_ice: mod09*s: StateQA mod35 Snow Ice
pixel_adjacent_to_cloud: mod13A2: if pixel is a cloud neighbour
icm_cloudy: mod09*i: Internal CM: Cloudy
icm_clear: mod09*i: Internal CM: Clear
icm_high_clouds: mod09*i: Internal CM: High Clouds
icm_low_clouds: mod09*i: Internal CM: Low Clouds
icm_snow: mod09*i: Internal CM: Snow
icm_fire: mod09*i: Internal CM: Fire
icm_sun_glint: mod09*i: Internal CM: Sun Glint
icm_dust: mod09*i: Internal CM: Dust
icm_cloud_shadow: mod09*i: Internal CM: Cloud Shadow
icm_pixel_is_adjacent_to_cloud: mod09*i: Internal CM: Pixel is Adjacent to Cloud
icm_cirrus: mod09*i: Internal CM: Cirrus
icm_pan_flag: mod09*i: Internal CM: Pan Flag
icm_criteria_for_aerosol_retrieval: mod09*i: Internal CM: Criteria for Aerosol Retrieval
icm_aot_has_clim_val: mod09*i: Internal CM: AOT (aerosol optical depth) has clim. val.
vi_usefulness: mod13A2: Quality estimation of the pixel
mixed_clouds: mod13A2: if pixel mixed with clouds
possible_snow_ice: mod13A2: if snow/ice present in pixel
possible_shadow: mod13A2: if shadow is present in pixel
platform: mcd43B2: Quality of BRDF correction performed
sun_z_angle_at_local_noon: mcd43B2: Quality of BRDF correction performed
band=string
Band number of MODIS product (mod09Q1=[1,2],mod09A1=[1-7],m[o/y]d09CMG=[1-7], mcd43B2q=[1-7])
Options: 1, 2, 3, 4, 5, 6, 7
1: Band 1: Red
2: Band 2: NIR
3: Band 3: Blue
4: Band 4: Green
5: Band 5: SWIR 1
6: Band 6: SWIR 2
7: Band 7: SWIR 3
DESCRIPTION
i.modis.qc extracts Requested Quality Assessment flags from the following MODIS products: MOD09A1,
MOD09Q1, MOD11A1, MOD11A2, MOD13A2, MCD43B2. This does include MOD09A1 QA_state_500m layer (see Notes).
MOD09A1/Q1: MODLAND QA Bits. bits=[0-1]
• [00]= class 0: Corrected product produced at ideal quality -- all bands
• [01]= class 1: Corrected product produced at less than ideal quality -- some or all bands
• [10]= class 2: Corrected product NOT produced due to cloud effect -- all bands
• [11]= class 3: Corrected product NOT produced due to other reasons -- some or all bands maybe be
fill value (Note that a value of [11] overrides a value of [01])
MOD09Q1: Cloud State. bits=[2-3]
• [00]= class 0: Clear -- No clouds
• [01]= class 1: Cloudy
• [10]= class 2: Mixed
• [11]= class 3: Not Set ; Assumed Clear
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]
• [0000]= class 0: highest quality
• [0111]= class 1: noisy detector
• [1000]= class 2: dead detector; data interpolated in L1B
• [1001]= class 3: solar zenith ≥ 86 degrees
• [1010]= class 4: solar zenith ≥ 85 and < 86 degrees
• [1011]= class 5: missing input
• [1100]= class 6: internal constant used in place of climatological data for at least one
atmospheric constant
• [1101]= class 7: correction out of bounds, pixel constrained to extreme allowable value
• [1110]= class 8: L1B data faulty
• [1111]= class 9: not processed due to deep ocean or cloud
• Class 10-15: Combination of bits unused
MOD09A1/Q1: Atmospheric correction bit=[12]/[30]
• [0]= class 0: Not Corrected product
• [1]= class 1: Corrected product
MOD09A1/Q1: Adjacency correction bit=[13]/[31]
• [0]= class 0: Not Corrected product
• [1]= class 1: Corrected product
MOD09Q1: Different orbit from 500m product, bit=[14]
• [0]= class 0: same orbit as 500m
• [1]= class 1: different orbit from 500m
MOD11A1: Mandatory QA Flags bits=[0-1]
• [00]= class 0: LST produced, good quality, not necessary to examine more detailed QA
• [01]= class 1: LST produced, other quality, recommend examination of more detailed QA
• [10]= class 2: LST not produced due to cloud effects
• [11]= class 3: LST not produced primarily due to reasons other than cloud
MOD11A1: Data Quality Flag bits=[2-3]
• [00]= class 0: Good data quality of L1B in bands 31 and 32
• [01]= class 1: Other quality data
• [10]= class 2: TBD
• [11]= class 3: TBD
MOD11A1: Emis Error Flag bits=[4-5]
• [00]= class 0: Average emissivity error ≤ 0.01
• [01]= class 1: Average emissivity error ≤ 0.02
• [10]= class 2: Average emissivity error ≤ 0.04
• [11]= class 3: Average emissivity error > 0.04
MOD11A1: LST Error Flag bits=[6-7]
• [00]= class 0: Average LST error ≤ 1
• [01]= class 1: Average LST error ≤ 2
• [10]= class 2: Average LST error ≤ 3
• [11]= class 3: Average LST error > 3
MOD11A2: Mandatory QA Flags bits=[0-1]
• [00]= class 0: LST produced, good quality, not necessary to examine more detailed QA
• [01]= class 1: LST produced, other quality, recommend examination of more detailed QA
• [10]= class 2: LST not produced due to cloud effects
• [11]= class 3: LST not produced primarily due to reasons other than cloud
MOD11A2: Data Quality Flag bits=[2-3]
• [00]= class 0: Good data quality of L1B in 7 TIR bands
• [01]= class 1: Other quality data
• [10]= class 2: TBD
• [11]= class 3: TBD
MOD11A2: Emis Error Flag bits=[4-5]
• [00]= class 0: Average emissivity error ≤ 0.01
• [01]= class 1: Average emissivity error ≤ 0.02
• [10]= class 2: Average emissivity error ≤ 0.04
• [11]= class 3: Average emissivity error > 0.04
MOD11A2: LST Error Flag bits=[6-7]
• [00]= class 0: Average LST error ≤ 1
• [01]= class 1: Average LST error ≤ 2
• [10]= class 2: Average LST error ≤ 3
• [11]= class 3: Average LST error > 3
MOD09A1s: Cloud State bits=[0-1]
• [00]= class 0: clear
• [01]= class 1: cloudy
• [10]= class 2: mixed
• [11]= class 3: not set, assumed clear
MOD09A1s: Cloud shadow bits=[2]
• [0]= class 0: no
• [1]= class 1: yes
MOD09A1s: Land/Water Flag bits=[3-5]
• [000]= class 0: Shallow ocean
• [001]= class 1: Land
• [010]= class 2: Ocean coastlines and lake shorelines
• [011]= class 3: Shallow inland water
• [100]= class 4: Ephemeral water
• [101]= class 5: Deep inland water
• [110]= class 6: Continental/moderate ocean
• [111]= class 7: Deep ocean
MOD09A1s: Aerosol Quantity bits=[6-7]
• [00]= class 0: Climatology
• [01]= class 1: Low
• [10]= class 2: Average
• [11]= class 3: High
MOD09A1s: Cirrus detected bits=[8-9]
• [00]= class 0: None
• [01]= class 1: Small
• [10]= class 2: Average
• [11]= class 3: High
MOD09A1s: Internal Cloud Algorithm Flag bits=[10]
• [0]= class 0: No cloud
• [1]= class 1: Cloud
MOD09A1s: Internal Fire Algorithm Flag bits=[11]
• [0]= class 0: No fire
• [1]= class 1: Fire
MOD09A1s: MOD35 snow/ice flag bits=[12]
• [0]= class 0: No
• [1]= class 1: Yes
MOD09A1s: Pixel adjacent to cloud bits=[13]
• [0]= class 0: No
• [1]= class 1: Yes
MOD09A1s: BRDF correction performed bits=[14]
• [0]= class 0: No
• [1]= class 1: Yes
MOD09A1s: Internal Snow Mask bits=[15]
• [0]= class 0: No snow
• [1]= class 1: Snow
MOD13A2: Mandatory QA Flags 1km bits[0-1]
• [00]= class 0: VI produced, good quality
• [01]= class 1: VI produced, but check other QA
• [10]= class 2: Pixel produced, but most probably cloud
• [11]= class 3: Pixel not produced due to other reasons than clouds
MOD13A2: VI Usefulness Flag bits[2-5]
• [0000]= class 0: Highest quality
• [0001]= class 1: Lower quality
• [0010]= class 2: Decreasing quality
• [0100]= class 3: Decreasing quality
• [1000]= class 4: Decreasing quality
• [1001]= class 5: Decreasing quality
• [1010]= class 6: Decreasing quality
• [1100]= class 7: Lowest quality
• [1101]= class 8: Quality so low that it is not useful
• [1110]= class 9: L1B data faulty
• [1111]= class 10: Not useful for any other reason/not processed
MOD13A2: Aerosol quantity Flags 1km bits[6-7]
• [00]= class 0: Climatology
• [01]= class 1: Low
• [10]= class 2: Average
• [11]= class 3: High
MOD13A2: Adjacent cloud detected 1km bit[8]
• [00]= class 0: No
• [01]= class 1: Yes
MOD13A2: Atmosphere BRDF correction performed 1km bit[9]
• [00]= class 0: No
• [01]= class 1: Yes
MOD13A2: Mixed clouds 1km bit[10]
• [00]= class 0: No
• [01]= class 1: Yes
MOD13A2: Land/Water Flags 1km bits[11-13]
• [000]= class 0: Shallow Ocean
• [001]= class 1: Land (Nothing else but land)
• [010]= class 2: Ocean Coastlines and lake shorelines
• [011]= class 3: Shallow inland water
• [100]= class 4: Ephemeral water
• [101]= class 5: Deep inland water
• [110]= class 6: Moderate or continental ocean
• [111]= class 7: Deep ocean
MOD13A2: Possible Snow/Ice 1km bits[14]
• [0]= class 0: No
• [1]= class 1: Yes
MOD13A2: Possible Shadow 1km bits[15]
• [0]= class 0: No
• [1]= class 1: Yes
MCD43B2: Albedo Quality Ancillary Platform Data 1km bits[0-3]
SDS: BRDF_Albedo_Ancillary
• [0000]= class 0: Satellite Platform: Terra
• [0001]= class 1: Satellite Platform: Terrra/Aqua
• [0010]= class 2: Satellite Platform: Aqua
• [1111]= class 15: Fill Value
• Classes 3-14: Not used
MCD43B2: Albedo Quality Ancillary Land/Water Data 1km bits[4-7]
SDS: BRDF_Albedo_Ancillary
• [0000] class 0: Shallow Ocean
• [0001] class 1: Land (Nothing else but land)
• [0010] class 2: Ocean and lake shorelines
• [0011] class 3: Shallow inland water
• [0100] class 4: Ephemeral water
• [0101] class 5: Deep inland water
• [0110] class 6: Moderate or continental ocean
• [0111] class 7: Deep ocean
• [1111] class 15: Fill Value
• Classes 8-14: Not used
MCD43B2: Albedo Quality Ancillary Sun Zenith Angle at Local Solar Noon Data 1km bits[8-14]
SDS: BRDF_Albedo_Ancillary
Returns integer value [0-90], 127 is Fill Value
MCD43B2: Band-wise Albedo Quality Data 1km
SDS: BRDF_Albedo_Band_Quality
bits[0-3][4-7][8-11][12-15][16-19][20-23][24-27]
• [0000]= class 0: best quality, 75% or more with best full inversions
• [0001]= class 1: good quality, 75% or more with full inversions
• [0010]= class 2: Mixed, 50% or less full inversions and 25% or less fill values
• [0011]= class 3: All magnitude inversions or 50% or less fill values
• [0100]= class 4: 75% or more fill values
• Classes 5-14: Not Used
• [1111]= class 15: Fill Value
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 more daily products.
SEE ALSO
i.vi
REFERENCES
• 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
AUTHOR
Yann Chemin
Last changed: $Date: 2014-12-12 00:16:30 +0100 (Fri, 12 Dec 2014) $
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