|
| EDG Data Set Name |
Granule Shortname |
| MODIS/Aqua Surface Reflectance 8-Day L3 Global 250m SIN Grid |
MYD09Q1 |
| Version |
Acquisition Range |
Science Quality Status |
| V003 |
March 6 2003 (2003065) |
Provisional |
Data Set Characteristics
Area = ~ 10° x 10° lat/long
Image Dimensions = 2 (4800x4800 row/column)
Average File Size = 138 MB
Resolution = 250 meters
Projection = Sinusoidal
Data Format = HDF-EOS
Science Data Sets (SDSs) = 3
Product Description
MODIS 250 m Surface Reflectance is a two-band product computed from the MODIS Level 1B land bands 1 and 2 (centered at 648 nm and 858 nm, respectively). The product is an estimate of the surface spectral reflectance for each band as it would be measured at ground level if there were no atmospheric scattering or absorption. A correction scheme reducing the effects of atmospheric gases,
aerosols, and thin cirrus clouds is applied to all pixels passing Level 1B quality control.
The MODIS/Aqua Surface Reflectance 8-Day L3 Global 250m SIN Grid product, MYD09Q1, is a composite of the previous 8 daily L2G Surface Reflectance products (MYD09GQK), which maintain the native 250m resolution in Bands 1 and 2. The best observations during an 8-day period, as determined by overall pixel quality and observational coverage, are matched geographically according to corresponding 250m Pointer Files (MYDPTQKM). Quality assurance data for the MYD09Q1 product is provided at three different levels of detail: at the individual pixel level, at each band and each resolution level, and at the level of the whole file.
NOTE: These products are validated, meaning that product uncertainties are well defined over a range of representative conditions. Although there may be later improved versions, these data are ready for use in scientific publications.
| SDS |
Units |
Data Type-bit |
Fill Value |
Valid Range |
Multiply by
Scale Factor |
| Surface Reflectance for band 1 (620-670 nm) |
reflectance |
16-bit signed integer |
-28672 |
-100 - 16000 |
0.0001 |
| Surface Reflectance for band 2 (841-876 nm) |
reflectance |
16-bit signed integer |
-28672 |
-100 - 16000 |
0.0001 |
| *Surface reflectance 250m quality control flags |
Bit field |
16-bit unsigned integer |
65535 |
0-4294966531 |
na |
*Quality Control Bit Index:
Bits are numbered from left (MSB) to right (LSB)
| Bit |
Description |
| 0 |
spare (unused); |
| 1 |
different orbit from 500 m; |
| |
1 -- yes |
| |
0 -- no |
| 2 |
adjacency correction performed; |
| |
1 -- yes |
| |
0 -- no |
| 3 |
atmospheric correction performed; |
| |
1 -- yes |
| |
0 -- no |
| 4-7 |
band 2 data quality four bit range; |
| |
0000 -- highest quality |
| |
1000 -- dead detector; data copied from adjacent detector |
| |
1001 -- solar zenith >= 86 degrees |
| |
1010 -- solar zenith >= 85 and < 86 degrees |
| |
1011 -- missing input |
| |
1100 -- internal constant used in place of climatological data for at least one atmospheric constant |
| |
1101 -- quality so low that it is not useful |
| |
1110 -- L1B data faulty |
| |
1111 -- not useful for any other reason or not processed due to deep ocean or clouds |
| 8-11 |
band 1 data quality four bit range; |
| |
SAME AS ABOVE |
| 12-13 |
cloud state; |
| |
00 – clear |
| |
01 – cloudy |
| |
10 – mixed |
| |
11 -- not set, assumed clear |
| 14-15 |
MODLAND QA bits; |
| |
corrected product produced at |
| |
00 -- ideal quality all bands |
| |
01 -- less than ideal quality some or all bands |
| |
corrected product not produced due to |
| |
10 -- cloud effects all bands |
| |
11 -- other reasons some or all bands may be fill value [Note that a value of (11) overrides a value of (01)]. |
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EOS Data Gateway Search Tips
| Data Center: |
LPDAAC |
| Sensor: |
MODIS |
| Dataset: |
MODIS/Aqua Surface Reflectance 8-Day L3 Global 250m SIN Grid |
| Spatial: |
HORIZONTALTILENUMBER Max/Min VERTICALTILENUMBER Max/Min |
| Geographic Extent: |
Type Lat/Long Range or Draw on Map |
| Temporal Extent: |
2003-03-06 to present |
Product Information 
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