CDAWeb Quick Start Guide

The NASA/GSFC Space Physics Data Facility (SPDF) developed CDAWeb, the Coordinated Data Analysis (Workshop) Web data browsing and listing tool in 1993, to support interactive plotting of variables from multiple instruments on multiple investigations simultaneously on arbitrary, user-defined time-scales. This system depends on data in [Common Data Format/CDF] (http://cdf.gsfc.nasa.gov/) or netCDF https://www.unidata.ucar.edu/software/netcdf/ containing metadata following the ISTP Metadata Guidelines. Data can be displayed as plots, listings, and output in CDF, netCDF, CSV, JSON, and audio files. Note, the early ISTP data use the term key parameters (KP, K0) to describe 1 minute quick-look data that is not as fully calibrated as higher-resolution (H0, H1, etc.) data.

This powerful capability was developed to support the coordinated science objectives of the International Solar Terrestrial Physics (ISTP) program and the InterAgency Consultative Group (IACG), and now supports the international heliophysics community as a whole. CDAWeb statistics are shown SPDF - Coordinated Data Analysis Web (CDAWeb).

CDAWeb System Layout

The interface to CDAWeb progresses through a series of pages (Home Page, Data Selector, Data Explorer), as depicted in the figure below.

Figure 1. CDAWeb System Diagram

HOME PAGE (known as the CDAWeb Source Selector Form)

· From this form, choose a mission group (e.g., Wind, Geosynchronous spacecraft, ground-based investigations) and/or instrument type (e.g., Magnetic Field (space), Particles (space), Ground-Based HF-Radars) to get a list of datasets. One of more items needs to be selected in one column or both columns.

· Mission groups and instruments are logically combined in a query such that selecting “Geotail” mission and “Magnetic Fields” instrument will only match Geotail Magnetic Field datasets as in a logical “AND” operation. Selection of multiple missions and multiple instruments becomes a logical “OR” operation; e.g., selecting Geotail and Wind missions and Electric Fields and Magnetic field instruments will match against all Geotail and Wind datasets that have either electric field or magnetic field data.

· Press the “submit” button to find matching datasets.

DATA SELECTOR

· Datasets matching your query are pre-selected in a list and may be unselected by clicking on the checkboxes.

· The list includes the dataset name, source name, PI and affiliation.

· Make your selections and press “submit” button to view the variables/parameters in those datasets.

DATA EXPLORER

· Variables/Parameters for each dataset are displayed on the data explorer form.

· Select start and stop time, which is pre-populated with the latest available time.

· Select activity (Download, List, or Plot) to perform the appropriate operation.

· Select variables only to List or Plot (download option lists all CDF data files for selected times including all variables).

· Press “submit” button to perform the action.

The data are then processed and displayed (as plots or listings), or you can download the CDF data files themselves.

·Plotting
The plots are in fact a set of PNG image(s) that can be easily downloaded and saved locally if desired. (Note that the powerful underlying IDL® plotting software is available for download to further analyze the datasets.)

· Listing
The listings are displayed as hyperlinks that can be displayed on the browser and/or saved directly as an ASCII file.

· Download CDFs
Selecting this option will generate a list of CDF datasets for the particular time period. Each file can be downloaded by clicking on the appropriate hyperlink.

Error Messages and Problems

A number of error messages are displayed when user input is invalid or missing required fields, system resources are unavailable, and other situations occur. Most of these error messages are explained in the error document.

There is a list of restrictions and problems with individual datasets available through CDAWeb.

CDAWeb displays data as line plots, stacked plots, scatter plots, spectrograms, images, plasmagrams, ionospheric convection patterns, and more, as shown below.

[IMP-8 time series plot]

Figure 2. A time series plot of data from the IMP-8 Three-axis magnetometer instrument.

[spectrogram image]
Figure 3. A spectrogram of electron Differential Flux at 322 East @ 12 Energies 30 to 2000 keV from the Energetic Particles/LANL Geosynchronous Investigation.

[Viking auroral oval mapped image plot]
Figure 4. Mapped image of the North Polar Cap from the Viking (Sweden) UV Auroral Imager.

[Wind Key Parameter 3DP stacked plot]
Figure 5. Stacked time series plot of Wind Electron Energy.

[polar projected thumbnail plots of TIMED GUVI data]
Figure 6. Large Thumbnail Polar plots of TIMED GUVI L1C Disk imager data.

[Animated gif of TIMED GUVI data]
Figure 7. Animated gif of TIMED GUVI L1C Disk imager data.

[Animated gif of TIMED TIDI data]
Figure 8. Animated gif of TIMED TIDI Wind Vector data.

[Bastille day movie to TEC data from GPS]
Figure 9. Bastille day movie of total electron content from the Global Positioning System (GPS).

[RPI Echo amplitude plasmagram]
Figure 10. IMAGE Radio Plasma Imager (RPI) Echo amplitude plasmagram.

[TWINS1 Neutral-atom Spectrometer Level-1 Magnetospheric Movie]
Figure 11. TWINS1 Neutral-atom Spectrometer Level-1 Magnetospheric Movie.

[THEMIS All Sky Imager Keograms (ASK)]
Figure 12. THEMIS All Sky Imager Keograms (ASK) for several stations (same time range as TWINS data above).

Additional plotting capabilities of CDAWeb are demonstrated with the following images for orbit plots and radar plots, respectively:

[orbit plot]

Figure 13. Orbit plot for GEOTAIL, POLAR, and WIND spacecraft.

[radar plot]

Figure 14, A radar plot of data from the DARN Goose Bay Ground-based measurements.

The original CDAWeb team SPDF - Coordinated Data Analysis Web (CDAWeb) and the current staff are shown at SPDF - staff.