GBDX

IDAHO Metadata Files

IDAHO metadata files and contents

IDAHO Image Metadata Files Overview

These are the metadata files associated with IDAHO images. Not all metadata files are available for all IDAHO images. The metadata files available for an IDAHO image depends on the data source of the image. See "profile" information below.

This is the list of metadata files for an image. Click the name to see an example and metadata descriptions.

File Name Description
image.json Core image metadata files
rrds.json A listing of Reduced Resolution Datasets available for the IDAHO image
georeferencing.json Georeferencing information for the IDAHO Image
rpcs.json DigitalGlobe RPC sensor model parameters
native_warp_spec.json Wrap grid for orthorectifying the IDAHO image
histogram.json Histogram for the IDAHO image

Profiles

IDAHO images fit into one of the profiles listed here. The profile indicates which types of metadata are available for that image.

Profile Name Source Image Metadata Types
dg_1b DigitalGlobe level 1B image image.json, rpcs.json file, native_warp_spec.json file, histogram.json file, 5 rrd levels, DG product metadata (.IMD, .XML, etc)
georectified_image geoferenced image (as opposed to a raw or otherwise unrectified image) image.json, georeferencing.json

vendor Dataset Identifier

For DigitalGlobe images the vendorDatasetIdentifier is formatted; "{PRODUCT_LEVEL}:{PRODUCT_ORDER_ID}:{CAT_ID}:{PRODUCT_CAT_ID}". This identifier is useful as a means to reference back to other vendor-supplied catalogs.

Example vendorDatasetIdentifier: "LV1B:053864309030_01_p001:1030010037A14B00:2020010129405000"

image.json

This file contains the core image metadata, such as number of rows/cols, data types, and other common values used to select the image. The image.json file is required for all IDAHO images.

Example image.json file

{
  "imageId": "bde4b243-a647-4699-807b-6abe0d6fcd12",
  "version": "1.0",
  "profileName": "dg_1b",
  "tileBucketName": "idaho-demo-oregon",
  "tilePartition": "0000",
  "nativeTileFileFormat": "TIF",
  "tileXOffset": 0,
  "tileYOffset": 0,
  "numXTiles": 35,
  "numYTiles": 27,
  "tileXSize": 256,
  "tileYSize": 256,
  "numBands": 8,
  "dataType": "UNSIGNED_SHORT",
  "imageHeight": 6773,
  "imageWidth": 8820,
  "sensorPlatformName": "WV02",
  "sensorName": "8-band (Coastal, Blue, Green, Yellow, Red, Red-edge, NIR1, NIR2) Multispectral",
  "vendorName": "DigitalGlobe, Inc.",
  "vendorDatasetIdentifier": "LV1B:053864309030_01_P001:1030010037A14B00:2020010129405000",
  "acquisitionDate": "2014-09-09T06:50:26.467Z",
  "colorInterpretation": "WORLDVIEW_8_BAND",
  "imageBoundsWGS84": "POLYGON ((58.71332241 25.66113728, 58.91368505 25.63821421, 58.91276839 25.50867659, 58.71402146 25.52907957, 58.71332241 25.66113728))",
  "groundSampleDistanceMeters": 2.229
}

Contents of image.json file

Element Type Description
imageId string The IDAHO ID
version string the IDAHO specification version
profileName string the profile that this IDAHO image conforms to. This can be used to know what files will exist for the image
tileBucketName string the bucket where the IDAHO images' tiles exist
tilePartition string the partition where the IDAHO images' tiles exist. This value is used in deriving each tile's hash prefix
nativeTileFileFormat string the image file format for the IDAHO images' tiles. Can be "PNG" or "TIF"
tileXOffset number the X offset for the first upper left pixel of the IDAHO image
tileYOffset number the Y offset for the first upper left pixel of the IDAHO image
numXTiles number the number of tiles across the X direction of the IDAHO image
numYTiles number the number of tiles in the Y direction of the IDAHO image
tileXSize number the number of pixels across the X direction in the IDAHO image tiles
tileYSize number the number of pixels in the Y direction in the IDAHO image tiles
numBands number the number of image bands in the IDAHO image tiles
dataType string the data type of the pixeles in the IDAHO image tiles
imageHeight number The number of pixels in the Y dimension of the IDAHO image
imageWidth number The number of pixels in the X dimension of the IDAHO image
sensorPlatformName string the name of the sensor platform (satellite) that captured the image
sensorName string the name of the sensor that captured the image
vendorName string the name of the company that produced the image
vendorDatasetIdentifier string the vendor specific ID of the image
acquisitionDate string The date time when the image was captured
colorInterpretation string the name that indicates the band order of the image
imageBoundsWGS84 string the WKT geographical bounds of the image
groundSampleDistanceMeters number the approximate size in meters of one pixel

rrds.json

This file contains a list of Reduced Resolution Datasets (RRDs) of the IDAHO image. RRDs have lower spatial resolution and therefore are smaller and quicker to load then the full dataset. They are used for quickly browsing over the imagery.

Example rrds.json file

{
    "reducedResolutionDataset": [{
        "sourceImage": "bde4b243-a647-4699-807b-6abe0d6fcd12",
        "targetImage": "f53538cc-58c0-4b4d-bb09-150f4ae4567d",
        "inverseScaleFactor": 2.0
    }, {
        "sourceImage": "f53538cc-58c0-4b4d-bb09-150f4ae4567d",
        "targetImage": "a35a0e9f-a07e-4df8-a72d-3c0e9bc9a315",
        "inverseScaleFactor": 2.0
    }, {
        "sourceImage": "a35a0e9f-a07e-4df8-a72d-3c0e9bc9a315",
        "targetImage": "7a315eb5-e9b5-4f89-bb0b-5abcbf43aec1",
        "inverseScaleFactor": 2.0
    }, {
        "sourceImage": "7a315eb5-e9b5-4f89-bb0b-5abcbf43aec1",
        "targetImage": "5df79860-90d3-4810-ade3-79ad0b063769",
        "inverseScaleFactor": 2.0
    }, {
        "sourceImage": "5df79860-90d3-4810-ade3-79ad0b063769",
        "targetImage": "d4adebe2-ee6b-401b-9d33-d2b9dfdbeaa2",
        "inverseScaleFactor": 2.0
    }]
}

Contents of rrds.json file

The rrds.json file contains a reducedResolutionDataset. Each rrd listed in the dataset consists of the following values:

Value Type Description
sourceImage string the IDAHO ID of the RRD source image
targetImage string the IDAHO ID of the RRD image
inverseScaleFactor number the scale factor used to produce the RRD

Location

RRDs will be located in the same S3 bucket as the source image.

georeferencing.json

This file contains the geographical referencing for the IDAHO image. The georeferencing metadata contains the parameters to build the affine transformation needed to georeference the image. IDAHO images with a profile of "georectified_image" will include the georeferencing.json file.

Example georeferencing.json

{
    "spatialReferenceSystemCode": "EPSG:4326",
    "scaleX": 4.48787913602941E-6,
    "scaleY": -4.48787913602941E-6,
    "translateX": -108.63281025606044,
    "translateY": 46.66991963106043,
    "shearX": 0.0,
    "shearY": 0.0
}

Contents georeferencing.json

Value Type Description
spatialReferenceSystemCode string the system:value that specifies the spatial reference system
scaleX number specifies the scale factor along the x axis
scaleY number specifies the scale factor along the x axis
translateX number specifies the displacement along the x axis
translateY number specifies the displacement along the y axis
shearX number specifies the shear factor along the x axis
shearY number specifies the shear factor along the y axis

rpcs.json

This file contains the RPC information, which can be used to rectify the image. This is a mathematical mapping from object space coordinates to image space coordinates.

The values in the rpcs.json are the same as the DigitalGlobe RPC00B file. Please refer to the DigitalGlobe Imagery Support Data Documentation for details .

Example rpcs.json file

{
    "spatialReferenceSystem": "EPSG:4326",
    "upperLeftCorner": {
        "x": 58.71332241,
        "y": 25.66113728
    },
    "upperRightCorner": {
        "x": 58.91368505,
        "y": 25.63821421
    },
    "lowerRightCorner": {
        "x": 58.91276839,
        "y": 25.50867659
    },
    "lowerLeftCorner": {
        "x": 58.71402146,
        "y": 25.52907957
    },
    "gsd": 2.002335609054977E-5,
    "lineOffset": 3386.0,
    "sampleOffset": 4409.0,
    "latOffset": 25.5849,
    "lonOffset": 58.8134,
    "heightOffset": 11.0,
    "lineScale": 3386.0,
    "sampleScale": 4410.0,
    "latScale": 0.0778,
    "lonScale": 0.1023,
    "heightScale": 501.0,
    "lineNumCoefs": [-0.01247868, -0.1699803, -1.193688, -0.01892405, -0.002366152, -1.213828E-4, -2.886388E-4, -7.654795E-4, 0.009362892, 5.499658E-6, 3.702268E-5, 1.141359E-4, 9.568873E-4, 1.545527E-4, 8.740161E-4, 0.003490795, 0.001083495, 1.617478E-5, 9.24004E-5, 1.716484E-5],
    "lineDenCoefs": [1.0, -0.005079786, -0.003750422, -6.034228E-4, 0.001396144, 1.490369E-7, 1.645065E-4, -5.660189E-4, 0.003022191, -9.087502E-4, -1.39079E-5, 3.636066E-6, -5.448129E-4, 7.65754E-6, -6.239931E-5, -0.001555249, -2.609868E-6, 8.087889E-8, -5.860598E-5, 9.089406E-7],
    "sampleNumCoefs": [-0.006631238, 1.025698, 4.836109E-5, -0.02188833, -0.002148, 1.639059E-4, 9.741724E-5, 0.005816214, -3.656549E-5, -3.09791E-6, -2.092807E-6, 1.607785E-5, -4.504992E-5, -5.230266E-6, -4.981685E-5, 1.146771E-4, 2.640311E-7, 1.915519E-6, 6.6408E-6, 1.156241E-7],
    "sampleDenCoefs": [1.0, 8.39283E-4, 0.00220421, -3.132964E-4, 3.887315E-5, -1.358456E-6, 1.434978E-6, 6.141316E-6, 4.193624E-5, -5.176659E-6, 1.161258E-7, 6.575535E-8, -1.242692E-6, 2.477381E-8, 7.813111E-7, -9.281618E-6, -1.879341E-8, 0.0, -1.391419E-7, 0.0],
    "postScaleFactorX": 1.0,
    "postScaleFactorY": 1.0
}

native_warp_spec.json

The native_warp_spec.json file contains the warp grid specification for the IDAHO image. The warp grid can be used to orthorectify the IDAHO image.

Example native_warp_spec.json file

{
    "numXCells": 201,
    "numYCells": 153,
    "targetGeoTransform": {
        "scaleX": 2.00234e-05,
        "scaleY": -2.00234e-05,
        "shearX": 0,
        "shearY": 0,
        "spatialReferenceSystemCode": "EPSG:4326",
        "translateX": 58.7133,
        "translateY": 25.6611
    },
    "warpPositions": [-4.91524, -3.30698, 38.9481, -8.94853, 82.0331, -15.1185, 125.709, -20.8939, 169.194 (this example list is truncated due to length)
    "xStart": 0,
    "xStep": 50,
    "yStart": 0,
    "yStep": 50
}

Contents of native_warp_spec.json file

Value Type Description
numXCells number number of cells (2D points) in the X direction
numYCells number number of cells (2D points) in the Y direction
targetGeoTransform (values below indicated by "*") targetGeoTransform (values below indicated by "*") Target output affine in the given spatialReferenceSystemCode
*spatialReferenceSystemCode string the system:value that specifies the spatial reference system
* scaleX number specifies the scale factor along the x axis
* scaleY number specifies the scale factor along the x axis
* translateX number specifies the displacement along the x axis
* translateY number specifies the displacement along the y axis
* shearX number specifies the shear factor along the x axis
* shearY number specifies the shear factor along the y axis
xStart number the X position of the upper left corner of the warp grid
yStart number the Y postion of the upper left corner of the warp grid
xStep number the X spacing in output pixels between the cells of the warp grid
yStep number the Y spacing in output pixels between the cells of the warp grid
warpPositions list list, a list of cells given in x1,y1,x2,y2,x3,y3,... order. The values represent input pixel row/col.

histogram.json

This file contains the histogram for the IDAHO image.

Note: Due to the length of each list in the histogram, an image of an example is being used here instead of real file contents.

Contents of histogram.json file

Value Type Description
histograms (list values starred below) list list of name/value pairs
*name string the name of the band
* histogram list a list of counts, one for each bin
numBins list list of number of bins, there will be one value for each band
numBands number number of bands in the histogram