Introduction

This page tries to inspect many of the different types of N-dimensional (spatiotemporal) gridded coverage topologies that could be stored in rasdaman, accompanying every case with GML Web Coverage Service (WCS) responses upon both trimming and slicing.

Despite some cases might rarely have a practical real-world example, here we want to give examples for as many allowed geometries as possible.

All responses will highlight the domainSet of each ​coverage, which will all translate to some ​gml:Grid rectified or referenceable subtype. In case of mixed rectilinear/curvilinear geometries, a non-standard so-called ReferenceableGridByArrayAndVectors type [1] will be used, for a more compact and convenient GML description.

Finally, we will assume that all the time series will be referenced by the daily-resolution (UoM=days [d]) ​ANSI-Date CRS along the temporal dimension, which (by default) has a t positive-onwards axis.

Abbreviations:

• GML : Geographic Markup Language
• CRS : Coordinate Reference System
• RTS : Regular Time Series
• ITS : Irregular Time Series
• MRTS : Moving Regular Time Series
• MITS : Moving Irregular Time Series

[1] P. Campalani, A. Beccati, and P. Baumann. Addressing verbosity in GML 3.3 ReferenceableGrid geometries for practical use cases, 2013. Article submitted for conference proceedings.

Topologies Index

Due to the high number of possible cases, hereinafter we propose a first main table for global view.
Each cell then links to a dedicated subsection with the GML descriptions (assume default namespace is "gml").

In the 1D case, it is also clear how the gridded coverages can cover datasets which are not usually associated with the concept of grids (e.g. trajectories)

ID	DIM	Description	Single object	RTS	ITS	MRTS	MITS
1	1D	Temporal series of data with no spatial reference	link 	link 	link 	—-	—-
2	1D	Point measurements (with spatial reference) on a straight line
2a		… parallel to a CRS axis (2D space)	link 	link 	link 	link 	link 
2b		… diagonal wrt CRS axes (in 2D space)	link 	link 	link 	link 	link 
2c		… diagonal wrt CRS axes (in 3D space)	link 	link 	link 	link 	link 

Examples

1 : 1D temporal series of aspatial data

This section covers time series of point observations with no spatial reference (or where the spatial reference was not considered relevant): in this case the only distinction is whether there is a regular time step between observations, or not. In its degenerate degenerate case, the series turns to a single point.

(Attach a scan of the sketches here with all types in this subcategory?)

1

GML coverage type	GML domainSet	native CRS
RectifiedCoverage	RectifiedGrid	​http://kahlua.eecs.jacobs-university.de:8080/def/crs/OGC/0.1/ANSI-Date

• WCS trimming: …subset=t("2013-01-01","2013-04-16")…

  <domainSet>
    <RectifiedGrid dimension="2" uomLabels= srsDimension= srsName=>
      <limits>
        <GridEnvelope>
          <low>1 1</low>
          <high>4 4</high>
        </GridEnvelope>
      </limits>
      <axisLabels>u v</axisLabels>
      <origin>
        <Point id="ID" srsName="urn:x-ogc:def:crs:EPSG:6.6:4329">
          <pos>1.2 3.3 2.1</pos>
        </Point>
      </origin>
      <offsetVector srsName="urn:x-ogc:def:crs:EPSG:6.6:4329">1.1 2.2 3.3</offsetVector>
      <offsetVector srsName="urn:x-ogc:def:crs:EPSG:6.6:4329">2.0 1.0 0.0</offsetVector>
    </RectifiedGrid>
  </domainSet>
  

• Slice-S

1-RTS

GML coverage type	GML domainSet	native CRS
ReferenceableCoverage	ReferenceableGridByVectors	​http://kahlua.eecs.jacobs-university.de:8080/def/crs/OGC/0.1/ANSI-Date

• WCS trimming: …
• Slice-S

  <domainSet>
  ...
  <\domainSet>
  

• Slice-T

  <domainSet>
  ...
  <\domainSet>
  

Up 

1-ITS

Up 

2: 1D spatial observations on a straight line

2a : … along a straight line, parallel to a CRS axis

2a

Up 

2a-RTS

Up 

2a-ITS

Up 

2a-MRTS

Up 

2a-MITS

Up 

2b : … along a straight diagonal line, not parallel to a CRS axis

2c : … along a straight diagonal line in the 3D space