A combination of Bands 1, 4, 3 displays an R, G, B Surface Reflectance image using 500-m data acquired between January 1 - 8, 2007 over much of Mexico (h08v06), giving a clear view of the pine-oak forests defining the Sierra Madre Occidental in the west, across the altiplano region occupying much of the Mexican interior.
The MODIS Surface Reflectance products provide an estimate of the surface spectral reflectance as it would be measured at ground level in the absence of atmospheric scattering or absorption. Low-level data are corrected for atmospheric gases and aerosols, yielding a level-2 basis for several higher-order gridded level-2 (L2G) and level-3 products.
MOD09A1 provides Bands 1–7 at 500-meter resolution in an 8-day gridded level-3 product in the Sinusoidal projection. Each MOD09A1 pixel contains the best possible L2G observation during an 8-day period as selected on the basis of high observation coverage, low view angle, the absence of clouds or cloud shadow, and aerosol loading. Science Data Sets provided for this product include reflectance values for Bands 1–7, quality assessment, and the day of the year for the pixel along with solar, view, and zenith angles.
Version-5 MODIS/Terra Surface Reflectance products are Validated Stage 2, meaning that accuracy has been assessed over a widely distributed set of locations and time periods via several ground-truth and validation efforts. Although there may be later improved versions, these data are ready for use in scientific publications.
Temporal Coverage | February 24, 2000 - |
Area | ~10 x 10 lat/long |
File Size | ~64 MB |
Projection | Sinusoidal |
Data Format | HDF-EOS |
Dimensions | 2400 x 2400 rows/columns |
Resolution | 500 meters |
Science Data Sets (SDS HDF Layers) | 13 |
Science Data Sets for MODIS Terra Surface Reflectance 8-Day L3 Global 500m SIN Grid V005 (MOD09A1):
Science Data Sets (HDF Layers) (13) |
UNITS |
BIT TYPE |
FILL |
VALID RANGE |
MULTIPLY BY SCALE FACTOR |
---|---|---|---|---|---|
500m Surface Reflectance Band 1 (620–670 nm) | Reflectance | 16-bit signed integer | -28672 | -100–16000 | 0.0001 |
500m Surface Reflectance Band 2 (841–876 nm) | Reflectance | 16-bit signed integer | -28672 | -100–16000 | 0.0001 |
500m Surface Reflectance Band 3 (459–479 nm) | Reflectance | 16-bit signed integer | -28672 | -100–16000 | 0.0001 |
500m Surface Reflectance Band 4 (545–565 nm) | Reflectance | 16-bit signed integer | -28672 | -100–16000 | 0.0001 |
500m Surface Reflectance Band 5 (1230–1250 nm) | Reflectance | 16-bit signed integer | -28672 | -100–16000 | 0.0001 |
500m Surface Reflectance Band 6 (1628–1652 nm) | Reflectance | 16-bit signed integer | -28672 | -100–16000 | 0.0001 |
500m Surface Reflectance Band 7 (2105–2155 nm) | Reflectance | 16-bit signed integer | -28672 | -100–16000 | 0.0001 |
500m Reflectance Band Quality | Bit Field | 32-bit unsigned integer | 4294967295 | 0–4294966531 | na |
Solar Zenith Angle | Degree | 16-bit signed integer | 0 | 0–18000 | 0.01 |
View Zenith Angle | Degree | 16-bit signed integer | 0 | 0–18000 | 0.01 |
Relative Azimuth Angle | Degree | 16-bit signed integer | 0 | -18000–18000 | 0.01 |
500m State Flags | Bit field | 16-bit unsigned integer | 65535 | 0–57343 | na |
Day of Year | Julian day | 16-bit unsigned integer | 65535 | 1–366 | na |
The QA information below is excerpted from an HDF-EOS file of the MODIS Surface Reflectance product MOD09A1.
The MOD09A1 product includes two QA layers, one relating band specific quality (Table 1), and the other presenting the surface reflectance state (Table 2).
Table 1: MOD09A1.005 500-meter Surface Reflectance Data QA Descriptions (32-bit)
Bit No. |
Parameter Name |
Bit Comb. |
Sur_refl_qc_500m |
---|---|---|---|
31 | adjacency correction performed | 1 | yes |
0 | no | ||
30 | atmospheric correction performed | 1 | yes |
0 | no | ||
26–29 | band 7 data quality four bit range | 0000 | highest quality |
1000 | dead detector; data interpolated in L1B | ||
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 | correction out of bounds pixel constrained to extreme allowable value | ||
1110 | L1B data faulty | ||
1111 | not processed due to deep ocean or clouds | ||
22–25 | band 6 data quality four bit range | SAME AS BAND ABOVE | |
18–21 | band 5 data quality four bit range | SAME AS BAND ABOVE | |
14–17 | band 4 data quality four bit range | SAME AS BAND ABOVE | |
10–13 | band 3 data quality four bit range | SAME AS BAND ABOVE | |
6–9 | band 2 data quality four bit range | SAME AS BAND ABOVE | |
2–5 | band 1 data quality four bit range | SAME AS BAND ABOVE | |
0–1 | MODLAND QA bits | 00 | corrected product produced at ideal quality all bands |
01 | corrected product produced at less than ideal quality some or all bands | ||
10 | corrected product not produced due to cloud effects all bands | ||
11 | corrected product not produced due to other reasons some or all bands may be fill value [Note that a value of (11) overrides a value of (01)]. |
Table 2: MOD09A1.005 500-meter Surface Reflectance Data State QA Descriptions (16-bit)
Bit No. |
Parameter Name |
Bit Comb. |
Sur_refl_state_500m |
---|---|---|---|
15 | internal snow algorithm flag | 1 | yes |
0 | no | ||
14 | BRDF correction performed | 1 | yes |
0 | no | ||
13 | Pixel is adjacent to cloud | 1 | yes |
0 | no | ||
12 | MOD35 snow/ice flag | 1 | yes |
0 | no | ||
11 | internal fire algorithm flag | 1 | fire |
0 | no fire | ||
10 | internal cloud algorithm flag | 1 | cloud |
0 | no cloud | ||
8–9 | cirrus detected | 00 | none |
01 | small | ||
10 | average | ||
11 | high | ||
6–7 | aerosol quantity | 00 | climatology |
01 | low | ||
10 | average | ||
11 | high | ||
3–5 | land/water flag | 000 | shallow ocean |
001 | land | ||
010 | ocean coastlines and lake shorelines | ||
011 | shallow inland water | ||
100 | ephemeral water | ||
101 | deep inland water | ||
110 | continental/moderate ocean | ||
111 | deep ocean | ||
2 | cloud shadow | 1 | yes |
0 | no | ||
0–1 | MOD35 cloud | 00 | clear |
01 | cloudy | ||
10 | mixed | ||
11 | not set, assumed clear |
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In the event that data distributed from the Land Processes DAAC are incorporated into your research, please supply the following acknowledgment within your published work: "These data are distributed by the Land Processes Distributed Active Archive Center (LP DAAC), located at the U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center (lpdaac.usgs.gov)." If possible, please e-mail or send us reprints/citations of papers or oral presentations based on data obtained from the LP DAAC (see below for mailing address and e-mail address). This will help us to stay informed of how the data are being utilized.
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47914 252nd Street
Sioux Falls, SD 57198-0001
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U.S. Geological Survey (USGS)
Center for Earth Resources Observation and Science (EROS)
47914 252nd Street
Sioux Falls, SD 57198-0001
Phone Number: | 605-594-6116 |
Toll Free: | 866-573-3222 |
866-LPE-DAAC | |
Fax: | 605-594-6963 |
Email: | lpdaac@eos.nasa.gov |
Web: | http://lpdaac.usgs.gov |