Ortho generic

Orthophotos as GeoTIFF or ECW tiles directly in an Ortho folder, already in the dataset's CRS. There is no metadata file: each tile's extent comes from its own georeferencing.

Folder layout#

<dataset bucket>/
└── Ortho/                 capital O, case-sensitive
    ├── tile_001.tif
    ├── tile_002.tiff
    └── area.ecw

The ortho folder is looked for under these names, in this order — the first containing at least one matching file wins:

1. Ortho/

A nested layout such as Ortho/tif/*.tif is not indexed. Put the rasters in Ortho/ itself.

Files#

A delivery may mix GeoTIFFs and ECWs in the same folder; every matching file is indexed.

There is no filename convention.

Georeferencing#

Each tile's extent comes from its embedded geotransform: the indexed boundary is the raster's axis-aligned bounding box, not the outline of its valid data. A GeoTIFF with no geotransform fails the run — it is not indexed in pixel space. Only the header is read (a ranged read); the pixel data is not downloaded during indexing.

• Each GeoTIFF's TIFF header and first IFD must parse (only the header is read; the pixel data is not downloaded). A corrupt or truncated TIFF fails the run, naming the file. ECW files are checked separately.
• Each GeoTIFF's full-resolution strips or tiles must all end inside the file (their offsets and byte counts are read from the header; the pixels are not downloaded). This catches a partial upload whose header survived, as it does when the header sits at the start of the file (a Cloud Optimized GeoTIFF, for one). Tiles left out on purpose, as GDAL's sparse files do, are fine.
• Each GeoTIFF must carry a ModelPixelScale/Tiepoint (or ModelTransformation). A file with none is not indexed: a pixel-space rectangle stamped with the dataset CRS would place the tile at the CRS origin and poison the dataset footprint.
• Each ECW file's header must parse (magic, version, dimensions, georeference). ECW v2 (classic 'e' header) and v3 (ISO ecw /ECW3 boxes) both parse. A truncated or corrupt header fails the run, naming the file.
• Each raster's CRS (GeoTIFF GeoKeys, ECW v2 GDT datum/projection names, or ECW v3 embedded GeoTIFF tags) must equal the dataset's 2D CRS. Nothing is reprojected. A mismatch, or a file with no recognised CRS, fails the run.

ECW#

.ecw files are accepted next to the GeoTIFFs. Version 2 and version 3 both parse; the native reader decodes either.

Coordinate reference system#

Nothing is reprojected. Each raster's CRS is read from the file header (GeoTIFF GeoKeys, or the ECW GDT datum/projection names) and compared to the dataset's 2D CRS. A mismatch, or a file with no recognised CRS, fails the run. Every tile must already be in that CRS. See Coordinates.

Ingest parameters#

None.

What you get back#

One indexed record per raster, all in a single set named O.

Re-running is safe and is the normal way to fix a bad delivery — see Re-running is safe.

Common failures#