Examples: SWOT, NISAR, model output and other data
A store holds any raster time series on one north-up grid in an EPSG coordinate system. This page lists the worked examples in the repository and the route for each kind of data. Each example has a README with its commands, run from a checkout of the repository.
Worked examples
| Example | Data | What you need | README |
|---|---|---|---|
| Sentinel-2 monthly composites | Planetary Computer, public | Nothing beyond the repository. See Sentinel-2 for your area | sentinel2_pc |
| SWOT water surface elevation | Two SWOT L2 HR Raster 100 m NetCDF files, Roanoke region, about 60 MB each | A free NASA Earthdata login to download them from PO.DAAC | swot_raster |
| NISAR backscatter | Two NISAR L2 GCOV windows, HH and HV, in linear power and dB | A free NASA Earthdata login, and two granules from ASF DAAC | nisar |
| SWOT intensity | Geocoded SWOT amplitude of Wax Lake | Inputs from a private project. The README names the public source granules | swot_intensity |
| Water masks | NDWI and water fraction derived from the Sentinel-2 composites | The output of the Sentinel-2 example | water_masks |
| PNG frames | 36 monthly true-color PNG frames with world files | The output of the Sentinel-2 example | png_frames |
| Your own GeoTIFFs, end to end | Any dated GeoTIFFs on one grid | Your files | Your own data, end to end |
| Notebook player | The public PNG demo store | chronozarr[notebook] and a local Jupyter or VS Code notebook | anywidget |
| leafmap map | The public demo store | chronozarr[leafmap] | leafmap |
Routes by kind of data
| Data | Route |
|---|---|
| Dated GeoTIFFs or COGs on disk or in S3 | chronozarr convert on the directory, a quoted glob or the s3:// prefix. See Convert your data |
| COGs at URLs, with dates in a table | chronozarr convert on a CSV or JSON manifest of URLs and dates. See Convert your data |
| A NetCDF file or a Zarr store with a time axis | chronozarr convert FILE OUT --variable NAME. See Convert your data |
An xarray DataArray in a script or notebook | chronozarr.encode(da, "my_store", crs="EPSG:32618"). See Python API |
| Rendered PNG frames from another tool | chronozarr convert on a manifest of frames with world files. See PNG frames |
| Sentinel-2 imagery that you have not downloaded | The Sentinel-2 pipeline. See Sentinel-2 for your area |
Model output
Model output on a regular grid converts like any other NetCDF or Zarr variable. A grid in latitude and longitude uses EPSG:4326:
chronozarr convert model.nc model_store --variable tas --crs EPSG:4326--crs is needed only when the file does not declare its coordinate system. --dims time=NAME,y=NAME,x=NAME names the axes when they are not time, y and x or the usual aliases such as lat and lon. convert reverses rows that run from south to north, so the store is north-up. A store cannot hold a curvilinear or rotated grid. Regrid such output to a regular grid first.