Viewing Tool Help

Web Interface

The Web-based tool, Viewing, consists of three components, in addition to the user interface. These components are

the name resolver,
the command-line program, viewing, and
the XMM-Newton Visibility Tool.

Viewing is a Web interface for the viewing command-line utility written by Dr. Koji Mukai. It calculates the seasonal viewing windows, as determined by the Sun angle constraints of various observatories. Viewing can also provide visibility window restrictions due to the angle with respect to the Moon, which is currently implemented for Swift. Orbital pole restrictions have also been implemented for Swift.

Given the nature of the tool, this should be used only to check for the approximate visibility windows. Internally, the Sun angle is calculated in 1-day steps, which limits the accuracy of the results. For time-critical observations near the edge of a viewing window as calculated with viewing, consult the respective mission for authoritative limits.

In the case of XMM-Newton, for which other constraints play an essential role, we have incorporated the visibility tool written by the XMM-Newton SOC.

The range of dates checked by the Web interface goes from the current date to two years in the future. That applies to all missions supported by Viewing except for XMM-Newton, whose range can vary from one to two years.

This integrated Web version of the Viewing Tool was developed and is maintained by Edward J. Sabol.

Command-Line Interface

Version 3.2 of the command-line tool, viewing, is available from

ftp://legacy.gsfc.nasa.gov/software/tools/

(Download the files viewing3_2.tar.gz and viewing_install.guide.)

Usage:: viewing [mission=<name>/range=n1-n2] [equinox=year] [from=dd-mmm-yy] [for=y.y / to=dd-mmm-yy] [input=<file>] [output=<file>]
or: viewing none

This file was last modified on Tuesday, 13-May-2008 17:56:40 EDT

For feedback or questions concerning Viewing, please contact Edward J. Sabol and Dr. Koji Mukai.