VXO_PREP IDL Users Guide

L. I. Etesi (CUA,FHNW/GSFC), Updated: 2009-05-05

Synopsis

vxo = obj_new('vxo_prep')
vxo->preprocess, instrument, [infile], [outfile=outfile], [list-of-args]

Requirements

vxo_prep requires the SSW gen tree to be installed. It also needs IDL version 6.4 or higher. And there must be Java version 1.5 or higher available.

Description

The vxo_prep object is part of the SolarSoftWare's gen tree and intended to offer users the capability to preprocess solar data remotely without having to install the instrument's software package or calibration data. There is a convenience wrapper routine called vso_prep. The file name this object is vxo_prep__define.pro.
vxo_prep is using the IDL/Java bridge and internally loading a Java object that does all the client - server communication for this object. Basically, vxo_prep is a wrapper object for the underlying Java object gov.nasa.gsfc.hessi.jidl.prep.client.bridge.VxoPrepClient.

instrument   This parameter specifies the image's instrument type. Currently, following values are allowed: eit, rhessi For information about the instrument preprocessing parameters, please refer to the appropriate IDL object description in SSW gen tree.
infile   Optional. The file parameter can be omitted if the instrument's preprocessing package implements an interval search, such as rhessi. Otherwise, it is a hyperlink to a web repository, a file path to a local file or a byte array of data.
outfile   Specifies the output file path and name. Currently, that parameter cannot be left out.
parameters   Optional. This parameter takes all additional instrument specific parameters as a comma separated list.

Return value

When creating an object instance the return value is TRUE if the underlying Java object could be created and FALSE if an error ocurred.

vxo_prep->preprocess has no return value.

Errors

The preprocessing routine might fail for various reasons. The routine vso_debug might give further information. Improved debugging functionality will be introduced in a future release.

Examples

All the following examples can be seen and executed sequentially by calling vso_prep_test.

The following example shows how to search for the eit image which is closest to April, 21 01:15 and then how to send the preprocessing request to the remote server with vso_prep. The returned image will be saved as eit.fits. For the use of vso_files see HYPERLINK

Finally, we create an eit object, which allows us to plot the image.

IDL> file = vso_files('21-apr-2002 01:15', inst='eit')
IDL> vxo = obj_new('vxo_prep')
IDL> vxo->preprocess, 'eit', file, out='eit.fits'
IDL> eit = obj_new('eit')
IDL> eit->read, 'eit.fits'
IDL> eit->plot, /color

The next command will return a clean rhessi image covering the interval April, 21 01:15 - April, 21 01:16 and save it as rhessi.fits Then we will create a rhessi object and plot the image.

IDL> vxo = obj_new('vxo_prep')
IDL> vxo->preprocessfile = vso_files('21-apr-2002 01:15', inst='eit'), 'rhessi', out='rhessi.fits', im_time_interval=['21-apr-2002 01:15', '21-apr-2002 01:16'], image_alg='clean'
IDL> rhessi = obj_new('rhessi')
IDL> rhessi->read, 'rhessi.fits'
IDL> rhessi->plot, /color