Accessing the DPAS from SolarSoft

This page is under construction – the software is still being debugged. Please report any problems.

The objective of the HELIO Data Provider Access Service (DPAS) is to find observations that match a user's search criteria. The DPAS can be accessed from SolarSoft through its REST interface; this is the technique used in the section on helio_setup but below we describe how this is done directly.

The simplest way is to define a time interval and list of instruments and call use_dpas_idlapi: 

  times = ['1-nov-2003 19:00', '2-nov-2003 09:00']
  oinst = 'SOHO__EIT,SOHO__CDS,SOHO__LASCO,CLUSTER_1__FGM,WIND__3DP,ACE__MAG,RHESSI__HESSI_HXR'

  file_list = use_dpas_idlapi(timerange=times, required_obsinst=oinst, report=report  [,/plot,/goes])

The List of Files found by the DPAS is returned as a structure; each record includes information about the start and end times of the observation, the instrument and observatory used and the observing domain (associated with the observation???), and the URL where the file can be found.

Tools to examine and use the returned List of Files structure can be found on the "Using the DPAS Results" page.

Date-Driven Query

It is possible to specify the query time range for a Date-Driven query in two ways.

You can simply specify the time interval using the timerange keyword: 

  times = ['1-nov-2003 19:00', '2-nov-2003 09:00']
  file_list = use_dpas_idlapi(timerange=times  [,req=oinst])
You you use the /preset switch – this allows you to select times intervals that have been pre-defined in a file. 
  file_list = use_dpas_idlapi(/preset  [,req=oinst])
The routine cascades down through several possible locations searching for the file: first it looks to see if file is define by the environment variable MY_VOBS_PRESETS; if not, it looks in the current directory for the file 'vobs_presets.txt'; if it is not found there, it looks for the file in the users home directory; if still not defined, it uses the file stored in the HELIO database the directory define by $HELIO_DTB.
(The file 'vobs_presets.txt' stored in $HELIO_DTB documents how the contents of the file are defined)

Event-Driven Query

To do an event-driven query, you should use the code described under helio_setup


R.D. Bentley
20 Aoril 2011