Os produtos de refletância da superfície do MODIS fornecem uma estimativa da refletância espectral da superfície, que seria medida no nível do solo na ausência de dispersão ou absorção atmosférica.
Os dados de baixo nível são corrigidos para gases atmosféricos e aerossóis.
A versão 6.1 do MYD09GQ fornece bandas 1 e 2 com resolução de 250 m em um produto L2G diário em grade na projeção sinusoidal, incluindo uma camada de controle de qualidade e cinco camadas de observação. Ele deve ser usado em conjunto com o MYD09GA, que armazena informações importantes de qualidade e geometria de visualização.
Controle de qualidade da refletância da superfície
Máscara de bits para QC_250m
Bits 0-1: bits de controle de qualidade do MODLAND
0: produto corrigido produzido com qualidade ideal – todas as bandas
1: Produto corrigido produzido com qualidade abaixo do ideal: algumas ou todas as bandas
2: Produto corrigido não produzido devido a efeitos de nuvem: todas as bandas
3: O produto corrigido não foi produzido por outros motivos
- algumas ou todas as bandas podem ser um valor de preenchimento (11). Um valor de (11) substitui um valor de (01).
Bits 2 a 3: Spare (não usado)
0: N/A
Bits 4 a 7: qualidade dos dados da banda 1
0: Melhor qualidade
7: Detector ruidoso
8: Detector inativo, dados interpolados em L1B
9: zênite solar >= 86 graus
10: zênite solar >= 85 e < 86 graus
11: Entrada ausente
12: constante interna usada no lugar de dados climatológicos para pelo menos uma constante atmosférica
13: correção fora dos limites, pixel restrito ao valor extremo permitido
14: Dados L1B com falha
15: Não processado devido a oceano profundo ou nuvens
Bits 8 a 11: qualidade dos dados da banda 2
0: Melhor qualidade
7: Detector ruidoso
8: Detector inativo, dados interpolados em L1B
9: zênite solar >= 86 graus
10: zênite solar >= 85 e < 86 graus
11: Entrada ausente
12: constante interna usada no lugar de dados climatológicos para pelo menos uma constante atmosférica
13: correção fora dos limites, pixel restrito ao valor extremo permitido
14: Dados L1B com falha
15: Não processado devido a oceano profundo ou nuvens
Bit 12: correção atmosférica realizada
0: Não
1: Sim
Bit 13: correção de adjacência realizada
0: Não
1: Sim
Bits 14-15: Spare (unused)
0: N/A
obscov
0
100
0,01
metros
Nenhum
Porcentagem de cobertura de observação
iobs_res
0
254
metros
Nenhum
Número da observação
orbit_pnt
0
15
metros
Nenhum
Ponteiro de órbita
granule_pnt
0
254
metros
Nenhum
Ponteiro de grânulo
Termos de Uso
Termos de Uso
Os dados e produtos do MODIS adquiridos pelo LP DAAC não têm restrições de uso, venda ou redistribuição subsequentes.
Os produtos de refletância da superfície do MODIS fornecem uma estimativa da refletância espectral da superfície medida no nível do solo na ausência de dispersão ou absorção atmosférica. Os dados de baixo nível são corrigidos para gases atmosféricos e aerossóis. A versão 6.1 do MYD09GQ oferece bandas 1 e 2 com resolução de 250 m…
[null,null,[],[[["\u003cp\u003eMYD09GQ provides daily surface reflectance data at 250m resolution for bands 1 (red) and 2 (near-infrared) from the MODIS sensor on the Aqua satellite.\u003c/p\u003e\n"],["\u003cp\u003eThe data is corrected for atmospheric effects, offering an estimate of surface reflectance as if measured at ground level.\u003c/p\u003e\n"],["\u003cp\u003eThis product includes quality assurance information and observation details, and is best used in conjunction with MYD09GA for complete viewing geometry and quality assessments.\u003c/p\u003e\n"],["\u003cp\u003eData is available from July 4, 2002 to December 9, 2024 and is freely available for use, sale, or redistribution.\u003c/p\u003e\n"],["\u003cp\u003eUsers can access and analyze this dataset through Google Earth Engine using the provided code snippet.\u003c/p\u003e\n"]]],["The NASA MODIS MYD09GQ dataset, provided by the USGS EROS Center, offers daily surface reflectance data from 2002-07-04 to 2025-02-20. It provides bands 1 and 2 at a 250m resolution, corrected for atmospheric gases and aerosols. Key actions include accessing the data via Earth Engine with the snippet `ee.ImageCollection(\"MODIS/061/MYD09GQ\")`, utilizing bands like `sur_refl_b01`, `sur_refl_b02`, and `QC_250m`, and employing quality assurance data. The dataset is globally available without use restrictions.\n"],null,["Dataset Availability\n: 2002-07-04T00:00:00Z--2025-08-30T00:00:00Z\n\nDataset Provider\n:\n\n\n [NASA LP DAAC at the USGS EROS Center](https://doi.org/10.5067/MODIS/MYD09GQ.061)\n\nCadence\n: 1 Day\n\nTags\n:\n [aqua](/earth-engine/datasets/tags/aqua) [daily](/earth-engine/datasets/tags/daily) [global](/earth-engine/datasets/tags/global) [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) [usgs](/earth-engine/datasets/tags/usgs) \nmyd09gq \n\nDescription \nThe MODIS Surface Reflectance products provide an estimate\nof the surface spectral reflectance as it would be measured at\nground level in the absence of atmospheric scattering or absorption.\nLow-level data are corrected for atmospheric gases and aerosols.\nMYD09GQ version 6.1 provides bands 1 and 2 at a 250m resolution in\na daily gridded L2G product in the Sinusoidal projection, including\na QC and five observation layers. This product is meant to be used\nin conjunction with the MYD09GA where important quality and viewing\ngeometry information is stored.\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/MYD09GQ)\n\nBands\n\n\n**Pixel Size**\n\n250 meters\n\n**Bands**\n\n| Name | Min | Max | Scale | Pixel Size | Wavelength | Description |\n|--------------------|------|-------|--------|------------|------------|---------------------------------------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|\n| `num_observations` | 0 | 127 | | meters | None | Number of observations per 250m pixel |\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| `QC_250m` | | | | meters | None | Surface reflectance quality assurance |\n| Bitmask for QC_250m - 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 - Bits 14-15: Spare (unused) - 0: N/A ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||\n| `obscov` | 0 | 100 | 0.01 | meters | None | Observation coverage percent |\n| `iobs_res` | 0 | 254 | | meters | None | Observation number |\n| `orbit_pnt` | 0 | 15 | | meters | None | Orbit pointer |\n| `granule_pnt` | 0 | 254 | | meters | None | Granule pointer |\n\nTerms 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\nCitations \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\nDOIs\n\n- \u003chttps://doi.org/10.5067/MODIS/MYD09GQ.061\u003e\n\nExplore with Earth Engine **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\nCode Editor (JavaScript) \n\n```javascript\nvar dataset = ee.ImageCollection('MODIS/061/MYD09GQ')\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_MYD09GQ) \n[MYD09GQ.061 Aqua Surface Reflectance Daily Global 250m](/earth-engine/datasets/catalog/MODIS_061_MYD09GQ) \nThe 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. MYD09GQ version 6.1 provides bands 1 and 2 at a 250m resolution ... \nMODIS/061/MYD09GQ, aqua,daily,global,modis,nasa,satellite-imagery,sr,surface-reflectance,usgs \n2002-07-04T00:00:00Z/2025-08-30T00:00:00Z \n-90 -180 90 180 \nGoogle Earth Engine \nhttps://developers.google.com/earth-engine/datasets\n\n- [https://doi.org/10.5067/MODIS/MYD09GQ.061](https://doi.org/https://doi.org/10.5067/MODIS/MYD09GQ.061)\n- [https://doi.org/10.5067/MODIS/MYD09GQ.061](https://doi.org/https://developers.google.com/earth-engine/datasets/catalog/MODIS_061_MYD09GQ)"]]
