Overview

A Point Feature Collection is a collection of files which the CDM can recognize as containing Point Features.

Constraints on Point Feature Collections

  • The component files of the collection must all be recognized as Point or Station Feature type by the CDM software.
  • The component files must be partitioned by time. The starting time must be part of the filename, in a way that can be extracted with a DateExtractor.
  • The component files are assumed to be homogeneous, that is, they contain the same collection of variables and attributes, and they must be on the same horizontal and vertical grid. The component files can differ only in their time coordinates and the actual data values.

Example Point Feature Collections

station data

<featureCollection name="Metar Station Data" harvest="true" 
                   featureType="Station" path="nws/metar/ncdecoded">
  <collection spec="/data/ldm/pub/decoded/netcdf/surface/metar/Surface_METAR_#yyyyMMdd_HHmm#.nc$" />
  <update startup="true" rescan="0 0/15 * * * ? *" trigger="allow"/>
  <protoDataset choice="Penultimate" />
  <pointConfig datasetTypes="cdmrFeature Files"/>
</featureCollection>

point data

<featureCollection name="Surface Buoy Point Data" harvest="true" 
                   featureType="Point" path="nws/buoy/ncdecoded">
  <collection spec="/data/ldm/pub/decoded/netcdf/surface/buoy/Surface_Buoy_#yyyyMMdd_HHmm#.nc$" />
  <update startup="true" rescan="0 0/15 * * * ? *" trigger="allow"/>
  <protoDataset choice="Penultimate" />
  <pointConfig datasetTypes="cdmrFeature Files"/>
</featureCollection>

pointConfig element

Defines options on feature collections with featureType=POINT or STATION

<pointConfig datasetTypes="cdmrFeature Files" />

where:

  • datasetTypes: list the dataset types that are exposed in the TDS catalog. The possible values are:
    • cdmrFeature: creates a CdmrFeature dataset. All of the files in the collection are treated as part of the same dataset.
    • Files: each component file of the collection is available separately, as in a datasetScan. A latest file will be added.

Notes:

  • If there is a serviceType=HTTPServer for the Feature Collection, it is removed from the virtual datasets (all except the Files datasets).
  • If an pointConfig element is not present, the default is datasetTypes="cdmrFeature Files". Specifying your own pointConfig completely overrides the datasetTypes default.