Data visualization in Naiad

The Naiad system embeds an image generation engine able to provide quicklooks of the data adapted to the type of pattern or parameter.

Image patterns

Depending on what kind of data is visualized, Naiad offers several types of images adapted to each sampling pattern or parameter representation :

  • map
  • spectrum
  • x/y curve

Map pattern

Map pattern allow geolocated visualization of scalar (raster image) or vector (arrows) variables in the specified projection. The web user interface of Naiad allows only interactively the Google like projection when requesting a data quicklook but any projection can be requested when requesting a data extraction (specifying map image as output format).

Many parameters can be adjusted as shown in this tutorial such as the colorbar range and palette, the background, etc...

Along-Track-map-patternExample of map image with along-track data (such as altimeter data, here Jason-1 significant wave height)
Swath-map-patternExample of map image with large swath data (here wind speed measured by QuikSCAT scatterometer)

Spectrum pattern


Wave-spectrumExample of 2D directional spectrum image (such as here a swell wave spectrum measured by ASAR onboard ENVISAT)

The 2D directional spectrum pattern is especially intend for spectral parameters such as the wave systems measured by SAR. In addition to the spectrum energy distribution, the image indicates the propagation direction of the satellite-embedded instrument (black arrow).

When using the Naiad web interface, the spectra images are displayed together with their location on a map. Click directly on a spectrum location on the map to open the spectrum image or use the forward/backward arrows to browse the spectra along-track.

X/Y curve pattern


X-Y-curve-patternExample of 2D (X/Y) curve image (used here to plot along-track significant wave height measured by Jason-1 altimeter)

The X/Y curve is especially intended to display along-track data (X being the time dimension along the track) such as altimeter or SAR wave mode data, and therefore get a section of a given parameter over the ocean.

Image generation workflow

Images are a particular type of output (or serialization) format and are not considered differently within Naiad system than any other formats such as NetCDF or HDF. As explained in the workflow section, the serialization is always the last step of the processing workflow which means that the same processing operators (remapping, merging, virtual variables, filtering) can be applied like for any data extraction. It is therefore possible to generate images of remapped data in a different projection, merging of several orbit file data, etc... as shown in the gallery below.