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MODIS (GeoTIFF)

MODIS optical data with daily revisit rate fetched using Global Imagery Browse Services (GIBS).


Introduction

For more information, please read the block description.

Block type: DATA

This block provides RGB images of the satellite sensor MODIS Terra. Terra's orbit around the Earth is timed so that it passes from north to south across the equator in the morning.

The satellite data is based on the Global Imagery Browse Services (GIBS). This block can also provide other MODIS-derived data such as the Normalized Difference Vegetation Index (NDVI) (rolling 8-day average) product or additional MODIS bands such as Corrected Reflectance for Bands 7-2-1. The block is different than most other data blocks. MODIS data is provided as a global daily coverage, separate scenes are not considered. This means that all geometric filters have essentially the same functionality: the dataset of the corresponding date for the supplied AOI will be provided.

The MODIS (GeoTIFF) block is one of the UP42 open source blocks. This block is intended to help you build your own custom data block from scratch. Checkout the source code in the public repository.

Supported parameters

For more information, please read the section Data source query filters.

  • bbox: The bounding box to use as an AOI. Use only bbox or intersects or contains.

  • intersects: A GeoJSON geometry to use as an AOI. Use only bbox or intersects or contains.

  • contains: A GeoJSON geometry to use as an AOI. Use only bbox or intersects or contains.

  • time: A date range to filter scenes on. Newest daily coverages up to the limit will be provided.

  • limit: An integer number of maximum results to return. Omit this to set limit to 1.

  • zoom_level: An integer defining the webmercator zoom level of this request, defaults to 9.

  • imagery_layers: An array of layer identifiers available from GIBS. See the Additional imagery layers section to find out more. Default is MODIS_Terra_CorrectedReflectance_TrueColor (RGB).

Example queries

{
  "nasa-modis:1": {
    "bbox": [
      10.285749882459642,
      36.81990749171028,
      10.40604628622532,
      36.9023036894614
    ],
    "time": null,
    "limit": 1,
    "zoom_level": 9,
    "imagery_layers": ["MODIS_Terra_CorrectedReflectance_TrueColor"]
  }
}

Output format

 {
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "bbox": [
        9.84375,
        36.59788913307021,
        10.546875,
        37.160316546736766
      ],
      "id": "7b4f92e9-58eb-4af2-9dd1-1d8be0adfa4b",
      "geometry": {
        "type": "Polygon",
        "coordinates": [
          [
            [
              10.546875,
              36.59788913307021
            ],
            [
              10.546875,
              37.160316546736766
            ],
            [
              9.84375,
              37.160316546736766
            ],
            [
              9.84375,
              36.59788913307021
            ],
            [
              10.546875,
              36.59788913307021
            ]
          ]
        ]
      },
      "properties": {
        "up42.data_path": "7b4f92e9-58eb-4af2-9dd1-1d8be0adfa4b.tif"
      }
    }
  ]
}

Download example output

You can create example output to use when testing processing blocks built to work with this data by running the block in a workflow via the console, and downloading the results in the job overview.

Advanced

Additional imagery layers

The full list of available imagery layers to be used with this block can be found here. These are layers available in GIBS that have the same extent and resolution and the MODIS RGB layer (MODIS_Terra_CorrectedReflectance_TrueColor).

IdentifierDescription
MODIS_Aqua_CorrectedReflectance_TrueColorAqua is the second MODIS satellite with an afternoon crossing time.
MODIS_Terra_NDVI_8DayA rolling 8-day NDVI average computed with MODIS Terra imagery.
MODIS_Terra_EVI_8DayA rolling 8-day EVI average computed with MODIS Terra imagery.
MODIS_Terra_CorrectedReflectance_Bands367Bands 3,6 and 7 are useful for determining Land/Cloud/Aerosols properties.
MODIS_Terra_CorrectedReflectance_Bands721Bands 7,2 and 1 are useful for determining Land/Cloud/Aerosols boundaries.

Example of imagery layers

The output file (GeoTIFF) will include all the layers in the imagery_layers job parameter appended in the order passed in the parameters. In other words, each added layer in the job parameters produces output for each layer in all the available bands. Tags are also written into the output file with the provenance of each of the bands.

For example, with these input parameters:

{
  "nasa-modis:1": {
    "bbox": [
      10.285749882459642,
      36.81990749171028,
      10.40604628622532,
      36.9023036894614
    ],
    "time": null,
    "limit": 1,
    "zoom_level": 9,
    "imagery_layers": ["MODIS_Terra_CorrectedReflectance_TrueColor",
               "MODIS_Terra_EVI_8Day"]
  }
}

The output file will include this GeoTIFF tags:

# Band 1.
band = 1
layer = MODIS_Terra_CorrectedReflectance_TrueColor

# Band 2.
band = 2
layer = MODIS_Terra_CorrectedReflectance_TrueColor

# Band 3.
band = 3
layer = MODIS_Terra_CorrectedReflectance_TrueColor

# Band 4.
band = 1
layer = MODIS_Terra_EVI_8Day

You can very easily use rasterio to read these tags as described in the documentation.

When loading a 4 band image with uint8 as data type into a software like QGIS, by default, band 4 is assumed to be the alpha band (or transparency band). Go to the layer properties in QGIS to remove band 4 as the alpha band.