Cloudy SolarSoftware

From RHESSI Wiki

Introduction

In our project "Extending the Virtual Solar Observatory (VSO)" we have combined features available in Solar Software (SSW) to produce an integrated environment, supporting data location, retrieval, preparation, and analysis. This workflow and examples are shown below. Our goal is an integrated analysis experience in IDL, easy-to-use but flexible enough to allow more sophisticated procedures such as multi-instrument analysis. To that end, we have made the transition from a locally oriented setting where all the analysis is done on the user’s computer, to an extended analysis environment where IDL has access to services available on the Internet. We have implemented a form of Cloud Computing that uses the VSO search and a new data retrieval and pre-processing server (PrepServer) that provides remote execution of instrument-specific data preparation. The raw and pre-processed data can be displayed with our plotting suite, PLOTMAN, which can handle different data types and perform basic data operations.

Our environment supports a growing number of solar instruments that currently includes RHESSI, SOHO/EIT, TRACE, SECCHI/EUVI, HINODE/XRT, and HINODE/EIS.

Requirements

• IDL 6.4 or higher
• Java 1.5 or higher
• SolarSoftware (SSW) with GEN package (standard)

Step 1: Finding

SHOW_SYNOP is a graphical user interface (GUI) to access and search the VSO and other locations for instrument data within a specified time interval. Search results can be directly downloaded into the active SSW IDL environment. To start searching with the widget, type "SHOW_SYNOP" in your SSW IDL environment (see Figure 1). The red box marks the VSO search form. "Start Time" and "End Time" specify the search interval and "remote sites ->" the instrument. A click on "Search" will query the VSO for data files, which will be displayed in the list indicated by the green box.

To search on the command line, open an SSW IDL session and use VSO_FILES, as indicated below.

Definition

  ; COMMAND
  urls = vso_files(tstart, tend, instrument=instrument)
 
  ; INPUT
  tstart: Start time ('Day-Month-Year Hour:Minute')
  tend: End time ('Day-Month-Year Hour:Minute')
  instrument: Instrument to search for (e.g. 'eit', 'euvi', etc.)
 
  ; RETURNS
  urls: An array of URLs pointing to remote data file repositories

Examples

  ; This will return one URL to the EIT image closest to January 25, 2007 06:55
  urls = vso_files('25-Jan-2007 06:55', instr='eit')
  print, urls
    http://sohodata.nascom.nasa.gov//archive/soho/private/data/processed/eit/lz/2007/01/efz20070125.070013
 
  ; This will return URLs to XRT images between January 25, 2007 06:00 and January 25, 2007 07:00
  urls = vso_files('25-Jan-2007 06:00', '25-Jan-2007 07:00', instrument='xrt')
  print, urls
    http://kurasuta.cfa.harvard.edu/DATA/2007/01/25/H0600/XRT20070125_060117.2.fits
    http://kurasuta.cfa.harvard.edu/DATA/2007/01/25/H0600/XRT20070125_060120.2.fits
    ...

Step 2: Pre-processing

Typically, instrument data found with the VSO are unprocessed level-0 data. The PrepServer offers remote pre-processing of those data from within SHOW_SYNOP or from the IDL command line before or after downloading. In SHOW_SYNOP search results are displayed in the list indicated by the green box. There are two different pre-processing behaviors:

• By default a click on "Download" retrieves the level-0 data file, stores it on the local hard drive and adds it the list in SHOW_SYNOP that is marked in blue. The level-0 data file is pre-processed by selecting it and clicking on "Display". This uploads that level-0 data file to the PrepServer where it is pre-processed, and downloads the pre-processed product to the local hard drive.
• In auto-preprocessing mode, which can be activated in the configuration menu (indicated in yellow), SHOW_SYNOP sends only the URL to the level-0 data file to the PrepServer and then downloads the pre-processed data, which saves bandwidth.

To pre-process level-0 data on the command line, use VSO_PREP:

Definition

  ; COMMAND
  vso_prep, infile, outfile=outfile, instrument=instrument, oprep=oprep, _extra=extra
 
  ; INPUT
  infile: A local or remote file to be pre-processed
  instrument: (optional) The instrument name. Default: Determined from infile
  _extra: (optional) This parameter will collect all additional input parameters
 
  ; OUTPUT
  outfile: (optional) A file name for the pre-processed file. Default: prep_infile
  oprep: (optional) An object that will be created after the pre-processing. It will allow for direct access to the data (i.e. for display)

Examples

  ; This searches the VSO for an EIT file and sends the returned link to the PrepServer for pre-processing
  urls = vso_files('25-Jan-2007 06:55', inst='eit')
  vso_prep, urls, out='eit.fits'
 
  ; This command will reconstruct a RHESSI clean 6-12keV image on the PrepServer
  vso_prep, instrument='rhessi', im_time_interval=['25-Jan-2007 06:53:44', '25-Jan-2007 06:57:40'], image_alg='clean', im_energy_binning=[6,12]

Step 3: Visualizing

The data are visualized with PLOTMAN, which handles different data types such as light curves, images, spectra, and spectrograms. It provides basic display operations such as zooming, image overlays, solar rotation, etc. To display data with PLOTMAN, simply select a data file in the list indicated in blue and click on "Display". If the data file has already been pre-processed, it will be displayed in a PLOTMAN window, otherwise it is first sent to the PrepServer for processing.

PLOTMAN can also be called from the command line:

Examples

  ; This command pre-processes an XRT image, writes it into an object and displays the XRT image in PLOTMAN
  vso_prep, 'http://kurasuta.cfa.harvard.edu/DATA/2007/01/25/H0600/XRT20070125_065656.3.fits', oprep=xrt
  xrt->plotman, /color

Documentation

• SolarSoftware
• Virtual Solar Observatory
• PrepServer
• PLOTMAN
• VSO_FILES
• VSO_PREP
• Complete Code Example

Contacts

• SHOW_SYNOP: Dominic Zarro (dominic dot zarro at nasa dot gov)
• PrepServer: Laszlo I. Etesi (laszlo dot etesi at nasa dot gov)
• PLOTMAN: Kim Tolbert (kim dot tolbert at nasa dto gov)