Data Models Concepts

Table of Contents

• Data Models Concepts
  • Coverage
  • Product
    • Browse
  • Collection
    • Mosaic
  • Type objects

Coverage

Coverages are groups of raster fields (e.g bands) combined with metadata (metadata provides additional information about the actual data). EOxServer provides the ability to retrieve the whole coverage or can provide a subset of the coverage using the Web Coverage Service WCS.

WCS standard provides the ability to retrieve sub-parts of the coverage (e.g certain bands or a smaller within the caverage bbox). Another option would be to request the coverage -or a sub-area of it- as a map using WMS request

Product

Products can be defined as a small collection of coverages.

Coverages -when it comes to data versatility- are very strict (e.g all the data fields (bands) in a coverage must must have the same size, grid (resolution), projection). Storing a set of bands with a varaity of resolutions can be done in a product data model.

In addition to coverages products contains metadata which provides additional information of the product ( e.g masks, noData value mask, satellite information ).

Browse

Products can be visualized using browses. which basically are pre-rendered images of the product.

Collection

A collection is a much broader collection for raster data, they consist of a number of products or coverages or even both.

Mosaic

A Mosaic is a separate type of collections, it is basically a collection with more strict rules -when it comes to correlation of the data fields-, for example all bands in a mosaic must have the same resolution, datatype and projection.

Type objects

type objects are json objects that contain information that defines the data model, (e.g bands definition and the datatype used ). There are 3 types used in EOxServer:

:CoverageType:contains the definitive information of Coverages ( e.g type name, bands, data type ). Mosaics are collections that uses coveragetype to define the rendered data, and thats where it’s strictness come from.

:ProductType:contains associated information with Products.

:Collectiontype:contains associated information with Collections.