يوفّر منتج MOD09Q1 تقديرًا لانعكاس الطيف على السطح
للنطاقَين 1 و2 بدقة 250 مترًا، ويتم تصحيحه
ليناسب الظروف الجوية، مثل الغازات والهباء الجوي وتشتت رايلي. بالإضافة إلى نطاقَي الانعكاس، يتم تضمين طبقة جودة. يتم اختيار قيمة لكل بكسل من جميع عمليات الاستحواذ خلال التركيب الذي يمتد 8 أيام استنادًا إلى التغطية العالية للملاحظات وزاوية العرض المنخفضة وعدم وجود سُحب أو ظل سحابة وتحميل الهباء الجوي.
يوفّر منتج MOD09Q1 تقديرًا لانعكاس الطيف على السطح في النطاقَين 1 و2 بدقة 250 مترًا، ويتم تصحيحه وفقًا للظروف الجوية، مثل الغازات والرذاذ وتشتت رايلي. بالإضافة إلى نطاقَي الانعكاس، يتم تضمين طبقة جودة أيضًا. يتم اختيار قيمة لكل بكسل …
[null,null,[],[[["\u003cp\u003eMOD09Q1 provides surface spectral reflectance for bands 1 and 2 at 250m resolution, corrected for atmospheric conditions.\u003c/p\u003e\n"],["\u003cp\u003eThis product includes a quality layer and selects the best pixel from an 8-day composite based on observation coverage, view angle, and cloud presence.\u003c/p\u003e\n"],["\u003cp\u003eData is available from February 18, 2000, to November 24, 2024, and is provided by NASA LP DAAC at the USGS EROS Center.\u003c/p\u003e\n"],["\u003cp\u003eReflectance values are provided for bands 1 (620-670nm) and 2 (841-876nm) along with quality assessment flags for data reliability.\u003c/p\u003e\n"],["\u003cp\u003eThe data is freely available for use, sale, and redistribution with proper citation to the LP DAAC.\u003c/p\u003e\n"]]],[],null,["# MOD09Q1.061 Terra Surface Reflectance 8-Day Global 250m\n\nDataset Availability\n: 2000-02-18T00:00:00Z--2025-08-13T00:00:00Z\n\nDataset Provider\n:\n\n\n [NASA LP DAAC at the USGS EROS Center](https://doi.org/10.5067/MODIS/MOD09Q1.061)\n\nCadence\n: 8 Days\n\nTags\n:\n[8-day](/earth-engine/datasets/tags/8-day) [global](/earth-engine/datasets/tags/global) [mod09q1](/earth-engine/datasets/tags/mod09q1) [modis](/earth-engine/datasets/tags/modis) [nasa](/earth-engine/datasets/tags/nasa) [satellite-imagery](/earth-engine/datasets/tags/satellite-imagery) [sr](/earth-engine/datasets/tags/sr) [surface-reflectance](/earth-engine/datasets/tags/surface-reflectance) [terra](/earth-engine/datasets/tags/terra) [usgs](/earth-engine/datasets/tags/usgs) \n\n#### Description\n\nThe MOD09Q1 product provides an estimate of the surface\nspectral reflectance of bands 1 and 2 at 250m resolution and corrected\nfor atmospheric conditions such as gasses, aerosols, and Rayleigh\nscattering. Along with the two reflectance bands, a quality layer\nis also included. For each pixel, a value is selected from all\nthe acquisitions within the 8-day composite on the basis of high\nobservation coverage, low view angle, the absence of clouds or\ncloud shadow, and aerosol loading.\n\nDocumentation:\n\n- [User's Guide](https://lpdaac.usgs.gov/documents/306/MOD09_User_Guide_V6.pdf)\n\n- [Algorithm Theoretical Basis Document (ATBD)](https://lpdaac.usgs.gov/documents/305/MOD09_ATBD.pdf)\n\n- [General Documentation](https://ladsweb.modaps.eosdis.nasa.gov/filespec/MODIS/61/MOD09Q1)\n\n### Bands\n\n\n**Pixel Size**\n\n250 meters\n\n**Bands**\n\n| Name | Min | Max | Scale | Pixel Size | Wavelength | Description |\n|----------------|------|-------|--------|------------|------------|-----------------------------------------------------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|\n| `sur_refl_b01` | -100 | 16000 | 0.0001 | meters | 620-670nm | Surface reflectance band 1 |\n| `sur_refl_b02` | -100 | 16000 | 0.0001 | meters | 841-876nm | Surface reflectance for band 2 |\n| `State` | | | | meters | None | Surface reflectance 250m state flags |\n| Bitmask for State - Bits 0-1: Cloud state - 0: Clear - 1: Cloudy - 2: Mixed - 3: Not set, assumed clear - Bit 2: Cloud shadow - 0: No - 1: Yes - Bits 3-5: Land/water flag - 0: Shallow ocean - 1: Land - 2: Ocean coastlines and lake shorelines - 3: Shallow inland water - 4: Ephemeral water - 5: Deep inland water - 6: Continental/moderate ocean - 7: Deep ocean - Bits 6-7: Aerosol quantity - 0: Climatology - 1: Low - 2: Average - 3: High - Bits 8-9: Cirrus detected - 0: None - 1: Small - 2: Average - 3: High - Bit 10: Internal cloud algorithm flag - 0: No cloud - 1: Cloud - Bit 11: Internal fire algorithm flag - 0: No fire - 1: Fire - Bit 12: MOD35 snow/ice flag - 0: No - 1: Yes - Bit 13: Pixel is adjacent to cloud - 0: No - 1: Yes - Bit 14: BRDF correction performed data - 0: No - 1: Yes - Bit 15: Internal snow mask - 0: No snow - 1: Snow ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||\n| `QA` | | | | meters | None | Surface reflectance 250m band quality control flags |\n| Bitmask for QA - Bits 0-1: MODLAND QA bits - 0: Corrected product produced at ideal quality - all bands - 1: Corrected product produced at less than ideal quality - some or all bands - 2: Corrected product not produced due to cloud effects - all bands - 3: Corrected product not produced for other reasons - some or all bands, may be fill value (11) \\[Note that a value of (11) overrides a value of (01)\\] - Bits 2-3: Spare (unused) - 0: N/A - Bits 4-7: Band 1 data quality - 0: Highest quality - 7: Noisy detector - 8: Dead detector, data interpolated in L1B - 9: Solar zenith \\\u003e= 86 degrees - 10: Solar zenith \\\u003e= 85 and \\\u003c 86 degrees - 11: Missing input - 12: Internal constant used in place of climatological data for at least one atmospheric constant - 13: Correction out of bounds, pixel constrained to extreme allowable value - 14: L1B data faulty - 15: Not processed due to deep ocean or clouds - Bits 8-11: Band 2 data quality - 0: Highest quality - 7: Noisy detector - 8: Dead detector, data interpolated in L1B - 9: Solar zenith \\\u003e= 86 degrees - 10: Solar zenith \\\u003e= 85 and \\\u003c 86 degrees - 11: Missing input - 12: Internal constant used in place of climatological data for at least one atmospheric constant - 13: Correction out of bounds, pixel constrained to extreme allowable value - 14: L1B data faulty - 15: Not processed due to deep ocean or clouds - Bit 12: Atmospheric correction performed - 0: No - 1: Yes - Bit 13: Adjacency correction performed - 0: No - 1: Yes - Bit 14: Different orbit from 500m - 0: No - 1: Yes - Bit 15: Spare (unused) - 0: N/A ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||\n\n### Terms of Use\n\n**Terms of Use**\n\nMODIS data and products acquired through the LP DAAC\nhave no restrictions on subsequent use, sale, or redistribution.\n\n### Citations\n\nCitations:\n\n- Please visit [LP DAAC 'Citing Our Data' page](https://lpdaac.usgs.gov/citing_our_data)\n for information on citing LP DAAC datasets.\n\n### DOIs\n\n- \u003chttps://doi.org/10.5067/MODIS/MOD09Q1.061\u003e\n\n### Explore with Earth Engine\n\n| **Important:** Earth Engine is a platform for petabyte-scale scientific analysis and visualization of geospatial datasets, both for public benefit and for business and government users. Earth Engine is free to use for research, education, and nonprofit use. To get started, please [register for Earth Engine access.](https://console.cloud.google.com/earth-engine)\n\n### Code Editor (JavaScript)\n\n```javascript\nvar dataset = ee.ImageCollection('MODIS/061/MOD09Q1')\n .filter(ee.Filter.date('2018-01-01', '2018-05-01'));\nvar falseColorVis = {\n min: -100.0,\n max: 8000.0,\n bands: ['sur_refl_b02', 'sur_refl_b02', 'sur_refl_b01'],\n};\nMap.setCenter(6.746, 46.529, 2);\nMap.addLayer(dataset, falseColorVis, 'False Color');\n```\n[Open in Code Editor](https://code.earthengine.google.com/?scriptPath=Examples:Datasets/MODIS/MODIS_061_MOD09Q1) \n[MOD09Q1.061 Terra Surface Reflectance 8-Day Global 250m](/earth-engine/datasets/catalog/MODIS_061_MOD09Q1) \nThe MOD09Q1 product provides an estimate of the surface spectral reflectance of bands 1 and 2 at 250m resolution and corrected for atmospheric conditions such as gasses, aerosols, and Rayleigh scattering. Along with the two reflectance bands, a quality layer is also included. For each pixel, a value is selected ... \nMODIS/061/MOD09Q1, 8-day,global,mod09q1,modis,nasa,satellite-imagery,sr,surface-reflectance,terra,usgs \n2000-02-18T00:00:00Z/2025-08-13T00:00:00Z \n-90 -180 90 180 \nGoogle Earth Engine \nhttps://developers.google.com/earth-engine/datasets\n\n- [https://doi.org/10.5067/MODIS/MOD09Q1.061](https://doi.org/https://doi.org/10.5067/MODIS/MOD09Q1.061)\n- [https://doi.org/10.5067/MODIS/MOD09Q1.061](https://doi.org/https://developers.google.com/earth-engine/datasets/catalog/MODIS_061_MOD09Q1)"]]
