all level 2 files | MODOCL2 | MODOCL2A | MODOCL2B | SST File
NOTE 1: unless otherwise specified, flags of 0 indicate good data and flags of 1 indicate bad data.
NOTE 2: This table was changed from zero-based to one-based on October 19 2000 (i.e. bits and flags are now numbered starting with 1 instead of 0, where 1 is the least significant bit). The flag numbers are now consistent with the attributes in the MODIS files.
NOTE 3: Last updated July 24 2002 for collection 3.
first 4 bytes from Cloud Mask flags
common flags: 1 byte for each pixel
| bit | flag description | flag value |
|---|---|---|
| 1 | Processing Status | 0=processed 1=unprocessed (due to subsampling) |
| 2 | Atmospheric Correction | 0=successful 1=failed due to atmos_corr, bad ancillary data, and/or sun glint |
| 3 | Satellite Zenith Angle | 0=ok 1=too large (>45) |
| 4 | Solar Zenith Angle | 0=ok 1=too large (>70) |
| 5 | Shallow water | 1=shallow (< 5km from coast, < 50 m deep, or inland lake) |
| 6 | Sun_Glint | For MODSST: 1=Glint > threshold For MODCOL: 1=max(nLw(678))-min(nLw(678))> threshold (in a 3x3 box) |
| 7 | Supp_Data | 1= Invalid or missing ancillary data |
| 8 | Land | 1=land (includes ephemeral water) |
| quality (1 byte) | ||
|---|---|---|
| bits | description | value |
| 1-2 | Mandatory Quality for all of Gordon's nLw bands | 0 = good, if common flags are clear, and
product-specific L2_flags 1-4 and 9-16 are clear.
1 = questionable, if large zenith angles 2 = cloud or sun glint contaminated 3 = bad other than cloud, if any input radiances are negative , or Atmospheric Correction failed, aerosol model==16,or Land |
| 3-4 | Mandatory Quality for Carder's clear water epsilon parameter | 0 = good, if common flags, input Lw flags
and product specific L2_flag 15 is clear.
1 = questionable, if any of: shallow, large zenith angles, bad ancillary data, or product-specific L2_flag 15 is set. 2 = cloud, if any input radiances are negative and saturated, sunglint, cloudy 3 = if any input radiances are negative and not saturated, or Atmospheric Correction failed, or Land |
| 5-8 | spare | |
| flags (2 bytes) | |
|---|---|
| bit | value |
| 1 | = Cloudy - Albedo @ 865 > threshold |
| 2 | = Bad_Lw - One or more bands missing |
| 3 | = Bad_Lw - Any LwXXX <= 0. |
| 4 | = Bad_Lw - Any band counts < 0 |
| 5 | = Atmos_Corr - Questionable polarization correction/mirror reflectance |
| 6 | = Atmos_Corr - Gordon aerosol failure |
| 7 | = Atmos_Corr - Epsilon out of range (< lower limit or > upper limit) |
| 8 | = Atmos_Corr - Any LaXXX <= 0. |
| 9 | = Atmos_Corr - Invalid Raleigh scattering data |
| 10 | = nLw550_low - Calculated nLw550 is too small |
| 11 | = Cocco - Coccolithophorid radiance exceeds threshold |
| 12 | = TurbidCase2 - Actual_rrs555 > Turbid_rs555 |
| 13 | = Hi_la865 - Calculated La865 is too large |
| 14 | = input Lw's for Carder's clear water epsilon band (11,13) are ok |
| 15 | = lo_eps - epsilon < threshold |
| 16 | = spare |
| quality (4 bytes) - ULONG | ||
|---|---|---|
| bits | description | value |
| 1-8 | spare | |
| 9-10 | Mandatory Quality for Hoge's PEB and PUB parameters | 0 = good, if common flags are clear, input Lw flags
are clear, and product-specific L2_flags 19-23 are clear
1 = questionable, if any :shallow, large zenith angles, bad ancillary data, or flags 19-23 2 = cloud, if any input radiances are negative and saturated, cloud or glint 3 = if any input radiances are negative and not saturated, or Atmospheric Correction failed, or Land, or product-specific L2_flags 11-15 are set |
| 11-12 | Mandatory Quality for Clark's Chlor_MODIS parameter | (quality level demoted by 1 if high zenith angle
or bad ancillary data)
0 = good, if pigc between 0.05 and 2.5 High probability of Case 1 waters, lowest uncertainty in the Lwn retrieval accuracy 1 = questionable, if pig_c between 2.5 and 25 High probability of a mix of Case 1 and Case 2 waters, higher uncertainty in the Lwn retrieval accuracy. 2 = if pig_c between (0.01 and 0.05) or (25.0 and 100.0), if <0.05 High probability of Case 1 waters, higher uncertainty in the Lwn retrieval accuracy. If >=25 Highest probability of Case 2 waters, highest uncertainty in the Lwn retrieval accuracy. 3 = if input radiances are negative ,glint ,cloudy, aerosol model==16 land or atmospheric correction problem ,pig_c <0.01 mg/m**3 or pigc > 100.0 mg/m**3 |
| 13-18 | spare | |
| 19-20 | Mandatory Quality for Abbott's FLH parameter | ( quality level demoted by 1 if high sat or
solar zenith angle or bad ancillary data)
0 = good, if common flags except shallow are clear, input Lw flags are clear, product specific flags clear 1 = questionable, flags 7 (FLH/CHL too large) or 9 (FLH too large) 2 = if FLH/Chl way too large, FLH way too large, or modis_chl=-1 3 = bad if input radiances are negative, cloudy/albedo, unprocessed, atmospheric correction problem, high solar zenith angle, glint, ancillary data problem, or land |
| 21-22 | Mandatory Quality for Abbott's Chlor Fluorescence efficiency parameter | (quality level demoted by 1 if high sat or solar
zenith angle or bad ancillary data)
0 = good, if common flags except shallow are ok, input Lw flags are clear, and product-specific L2_flags are clear 1 = questionable, FLH qual is 1 or flag 12 2 = cloud, if FLH bad, CFE too high, or flag 11 3 = bad if input radiances are negative, cloudy/albedo, unprocessed, atmospheric correction problem, high solar zenith angle, glint, ancillary data problem, land, CFE way too high, or FLH qual is bad |
| 23-24 | Mandatory Qual for Gordon's cocco_pigmnt_conc, cocco_conc_detach, calcite_conc parameters | 0 = good, if common flags are clear, input Lw flags
are clear, and product-specific L2_flags clear.
1 = questionable, if any of: shallow, large zenith angles, bad ancillary or product flags 15-17 2 = cloud, if any input radiances are negative and saturated, cloud, or glint 3 = if any input radiances are negative and not saturated, or Atmospheric Correction failed, aerosol model==16, or Land, or product-specific flags 22-24 are set |
| 25-26 | Mandatory Quality for Clark's CZCS_pigment parameter | (quality level demoted by 1 if high sat or solar
zenith angle or bad ancillary data)
0 = good, if pigc between 0.05 and 2.5 High probability of Case 1 waters, lowest uncertainty in the Lwn retrieval accuracy 1 = questionable, if pig_c between 2.5 and 25 High probability of a mix of Case 1 and Case 2 waters, higher uncertainty in the Lwn retrieval accuracy. 2 = if pig_c between (0.01 and 0.05) or (25.0 and 100.0), if <0.05 High probability of Case 1 waters, higher uncertainty in the Lwn retrieval accuracy. If >=25 Highest probability of Case 2 waters, highest uncertainty in the Lwn retrieval accuracy. 3 = if input radiances are negative ,glint ,cloudy, land or atmospheric correction problem, pig_c <0.01 mg/m**3 or pigc > 100.0 mg/m**3 |
| 27-28 | Mandatory Quality for Clark's pigment_c1_total parameter | (quality level demoted by 1 if high sat or solar
zenith angle or bad ancillary data)
0 = good, if pigc between 0.05 and 2.5 High probability of Case 1 waters, lowest uncertainty in the Lwn retrieval accuracy 1 = questionable, if pig_c between 2.5 and 25 High probability of a mix of Case 1 and Case 2 waters, higher uncertainty in the Lwn retrieval accuracy. 2 = if pig_c between (0.01 and 0.05) or (25.0 and 100.0), if <0.05 High probability of Case 1 waters, higher uncertainty in the Lwn retrieval accuracy. If >=25 Highest probability of Case 2 waters, highest uncertainty in the Lwn retrieval accuracy. 3 = if input radiances are negative ,glint ,cloudy, aerosol model==16, land or atmospheric correction problem, pig_c <0.01 mg/m**3 or pigc > 100.0 mg/m**3 |
| 29-30 | Mandatory Quality for Clark's susp_solids_conc parameter | (quality level demoted by 1 if high sat or solar
zenith angle or bad ancillary data)
0 = good, if susp_solid between 0.3 and 1.2 High probability of Case 1 waters, lowest uncertainty in the retrieval accuracy due to in situ optics and TSM measurement accuracy 1 = questionable, susp_solid between 1.2 and 30 High probability of mix of Case 1 and Case 2 waters, higher uncertainty in the optical retrieval accuracy 2 = if susp_solid between 0.03 and 0.05 or 30.0 and 100.0 3 = if any input radiances are negative and not saturated, or Atmospheric Correction failed, glint, aerosol model==16, or susp_solid less than 0.03 or greater than 100 g/m**3, land, cloud |
| 31-32 | Mandatory Quality for Clark's k490 parameter | (quality level demoted by 1 if high sat or solar
zenith angle or bad ancillary data)
0 = good, K490 < 0.20, Uncertainty = 18% 1 = questionable, if K490 between 0.020 and 0.025 Uncertainty=20% 2 = cloud, if K490 between 0.025 and 0.03 Uncertainty>20% 3 = if any input radiances are negative and not saturated, or Atmospheric Correction failed, glint, aerosol model==16, k490 <0.0 or k490 > 0.03, if >0.03 uncertainty=50%, or land, cloudy |
| flags (3 bytes) | |
|---|---|
| 1 | =0 if pig_c input Lw's (9,12) are ok |
| 2 | =0 if Chl_A input Lw's (9,10,11,12) are ok |
| 3 | =0 if pig_total input Lw's (9,10,11,12) are ok |
| 4 | =0 if susp_solid input Lw's (9,10,11,12) are ok |
| 5 | =0 if k490 input Lw's (9,12) are ok |
| 6 | =0 if Abbott's FLH/chl_modis reasonable |
| 7 | =0 if Abbott's FLH/chl_modis good |
| 8 | =0 if FLH reasonable value |
| 9 | FLH_Range - FLH out of range |
| 10 | chl_modis algorithm failed (fill value present) |
| 11 | ARP qual >=2, questionable |
| 12 | ARP qual = 1, higher uncertainty |
| 13 | CFE too high |
| Gordon Cocco: | |
| 14 | =0 if cocco input Lw's (9,12) are ok |
| 15 | LoRadiance - value below lower bound of lookup table |
| 16 | HiRadiance - value above upper bound of lookup table |
| 17 | InvalidEntry - invalid data in lookup table |
| Hoge: | |
| 18 | Hoge's peb,pub input Lw's (8-12) are ok |
| 19-23 | range_iop_flags[5]: 5 separate flags; one for each IOP to flag if any IOP is outside of an expected realistic range. *** If any one of these flags is set, output IOPs are suspect. |
| 24 | cloudy - albedo(865) > threshold |
| quality (1 byte) | ||
|---|---|---|
| bits | description | value |
| 1-2 | Mandatory Quality for Carder's chlor_a_3, absorp_coeff_gelb, chlor_absorb, tot_absorb_* | 0 = good, if common flags are clear, input
Lw flags are clear, and product-specific L2_flags 1,9-16 are clear
1 = questionable, if any of: shallow, large zenith angles, bad ancillary, or aphi675 too small 2 = cloud, if any input radiances are negative and saturated, cloud, or glint 3 = if any input radiances are negative and not saturated, or Atmospheric Correction failed, or Land, or aerosol model==16 |
| 3-4 | Mandatory Qual for Carder's ipar parameter | 0 = good, if common flags are clear, input
Lw flags are clear, and product-specific L2_flags clear
1 = questionable, if any of: shallow, large zenith angles, bad ancillary 2 = cloud, if any input radiances are negative and saturated, cloud or glint 3 = if any input radiances are negative and not saturated, or Atmospheric Correction failed, or Land, or aerosol model==16 |
| 5-6 | Mandatory Qual for Carder's arp parameter | 0 = good, if common flags are clear, input
Lw flags are clear, and product-specific L2_flags is clear
1 = questionable, if any of: shallow, large zenith angles, bad ancillary, or flags 2,12 2 = cloud, if any input radiances are negative and saturated, cloud or glint 3 = if any input radiances are negative and not saturated, or Atmospheric Correction failed, or Land, or aerosol model==16 |
| 7-8 | Mandatory Quality for SeaWiFs analog OC3M Chlorophyll chlor_a2 | (quality level demoted by 1 if high
zenith angle or bad ancillary data)
0 = good, if seawifs chl between 0.05 and 2.5 High probability of Case 1 waters, lowest uncertainty in the Lwn retrieval accuracy 1 = questionable, if pig_c between 2.5 and 25 High probability of a mix of Case 1 and Case 2 waters, higher uncertainty in the Lwn retrieval accuracy. 2 = if pig_c between (0.01 and 0.05) or (25.0 and 100.0), if <0.05 High probability of Case 1 waters, higher uncertainty in the Lwn retrieval accuracy. If >=25 Highest probability of Case 2 waters, highest uncertainty in the Lwn retrieval accuracy. 3 = if input radiances are negative ,glint ,cloudy, aerosol model==16, land or atmospheric correction problem, pig_c <0.01 mg/m**3 or pigc > 100.0 mg/m**3 |
| flags (2 bytes) | |
|---|---|
| Carder Chlorophyll: | |
| 1 | =0 if input Lw's (8-13) for Carder's bands are ok |
| 2 | neg_rrs_flag - one or more rss are less than or equal to zero |
| 3 | low_412_flag - rss[0](412) less than thresh_412 |
| 4 | low_555_flag - rss[4](555) less than thresh_555 |
| 5 | default_flag - using default chlorophyll model |
| 6 | chl_inconsistent_flag - calc chl exceeds chl_incon._thresh |
| 7 | chl_quality_flag - (currently unused) |
| 8 | hi_scat_flag - (currently unused) |
| 9 | blend_flag - aph_mod between .03 and .06 chlor. blend |
| 10 | package_flag - chl packaged or unpackaged |
| Carder PAR: | |
| 11 | =0 if ipar,arp input Lw's (8-13) are ok |
| 12 | hi_windspeed - wind speed > threshold |
| 13 | cloudy - albedo(865) > threshold |
| 14 |
chl_a3, high packaging
|
| 15 | (reynodolsst-ndtsst)> 3.0 ; Carder NDT un-packaged |
| 16 | (reynodolsst-ndtsst) < 1.8 ; Carder NDT packaged |
| quality (1 byte) | ||
|---|---|---|
| bits | description | value |
| 1-2 | Mandatory Qual for SST band | 0 = good, if common flags are clear, input
radiance flags are clear, and product-specific L2_flags 9,11-16 are clear
1 = questionable, large zenith angle, bad ancillary or flags 3,10-11 2 = sun glint or channel uniformity bad contaminated 3 = if any input radiances are negative and not saturated, or Atmospheric Correction failed, or land |
| 3-4 | Mandatory Qual for SST4 band | 0 = good, if common flags are ok, inputs,
both sat zenith tests, both sst4-sst, BT22-BT23-ref, both uniformity,
brights, and reynolds(optional)
1 = questionable, if any of: if sst4-sst test2 , sat zenith test 2, or unif test2 2 = if sst4-sst test 1, sat zenith angle test 1, or uniformity test1 3 = if any input radiances are negative and not saturated, BT22-BT23-ref out of range, bright outside (-4..33) |
| 5-8 | spare | |
| flags (2 bytes) | |
|---|---|
| 1 | =0 if sst input Lw's (20,31,32) are ok |
| 2 | =0 if sst4 input Lw's (20,22,23) are ok |
| 3 | 31/32 uniformity test 1 |
| 4 | 31/32 uniformity test 2 |
| 5 | 31/32 zenith angle 1 |
| 6 | 31/32 zenith angle 2 |
| 7 | 31/32 tree test |
| 8 | 31/32 SST different from reference |
| 9 | 20/31/32 brightness temperatures ok |
| 10 | 22/23 uniformity test 1 |
| 11 | 22/23 uniformity test 2 |
| 12 | 22/23 zenith angle 1 |
| 13 | 22/23 zenith angle 2 |
| 14 | 22/23 tree test |
| 15 | 22/23 SST different from reference |
| 16 | 20/22/23 brightness temperatures ok |
back to MODIS Ocean Data Processing home page
Documented by Jasmine S. Bartlett, COAS, Oregon State University.