Data Access
The DESI data are accessible through several means:
SPARCL
SPectra Analysis & Retrievable Catalog Lab (SPARCL) at NOIRLab provides flexible access to spectra from large optical and near-infrared surveys. SPARCL currently contains spectra from DESI and SDSS. The SPARCL client package is pre-installed in the Astro Data Lab and can also be installed in a user's local computing environment. See the How to Use SPARCL Jupyter Notebook.
Data Lab Table Access Protocol (TAP) service
TAP provides a convenient access layer for the DESI catalog database tables. TAP-aware clients (such as TOPCAT) can point to https://datalab.noirlab.edu/tap, select the desi_dr1 database, and see the database tables and descriptions (the desi_edr database is still available but is now superseded). Descriptions of the associated tables can also be found in the Data Lab table browser. The primary spectroscopic measurements are contained in the desi_dr1.zpix table (grouped and coadded by HEALPixel).
Data Lab Query Client
The Query Client is available as part of the Data Lab software distribution. The Query Client provides a Python API to Data Lab database services. These services include anonymous and authenticated access through synchronous or asynchronous queries of the catalog made directly to the database. Additional Data Lab services for registered users include personal database storage and storage through the Data Lab VOSpace.
The Query Client can be called from a Jupyter Notebook on the Data Lab Notebook server. Example notebooks are provided to users upon creation of their user account (register here), and are also available to browse on GitHub at https://github.com/astro-datalab/notebooks-latest.
Jupyter Notebook Server
The Data Lab Jupyter Notebook server (authenticated service) contains multiple examples of how to access and visualize the DESI catalogs and spectra:
- How to Use SPARCL
- Introduction to DESI First Data Release (DR1) at the Astro Data Lab
- Comparing SDSS and DESI spectra using SPARCL
- Stacking SDSS Spectra of Galaxies Selected from the BPT Diagram
- Multi-wavelength Image Cutouts and SDSS Spectra of Active Galaxies with Extreme Emission-Line Ratios
- Obtain spectra with SPARCL and plot them with Jdaviz
- Obtain spectra with SPARCL and plot them with Prospect
Bulk File Access
To download catalog files and/or spectra files from the public data releases NERSC or for bulk transfer using Globus see the Data Access page from the DESI Data Documentation website.
