Astronomy Visualization Metadata (AVM) is a standard for tagging digital astronomical images stored in formats such as
JPEG
JPEG ( ) is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and im ...
,
GIF
The Graphics Interchange Format (GIF; or , see pronunciation) is a bitmap image format that was developed by a team at the online services provider CompuServe led by American computer scientist Steve Wilhite and released on 15 June 1987. ...
,
PNG and
TIFF
Tag Image File Format, abbreviated TIFF or TIF, is an image file format for storing raster graphics images, popular among graphic artists, the publishing industry, and photographers. TIFF is widely supported by scanning, faxing, word processin ...
.
[ Astronomy Visualization Metadata Standard](_blank)
/ref> The AVM standard extends the concept of Extensible Metadata Platform
The Extensible Metadata Platform (XMP) is an ISO standard, originally created by Adobe Systems Inc., for the creation, processing and interchange of standardized and custom metadata for digital documents and data sets.
XMP standardizes a dat ...
(XMP) headers to include useful astronomical information about the subject of the image as well as the telescope used to take the image. This ensures that relevant information is transferred with the image when it is shared with others. AVM could be considered analogous to the FITS
Flexible Image Transport System (FITS) is an open standard defining a digital file format useful for storage, transmission and processing of data: formatted as multi-dimensional arrays (for example a 2D image), or tables. FITS is the most comm ...
headers associated with raw astronomical data files.
The standard was proposed by the Virtual Astronomy Multimedia Project, part of the IAU
The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach ...
Commission 55 and the International Virtual Observatory Alliance The International Virtual Observatory Alliance or IVOA is a worldwide scientific organisation formed in June 2002. Its mission is to facilitate international coordination and collaboration necessary for enabling global and integrated access to data ...
. It reached version 1.1 on May 14, 2008.[ AVM 1.1 Final Candidate](_blank)
/ref> The standard is currently used to tag images from the Chandra X-ray Observatory
The Chandra X-ray Observatory (CXO), previously known as the Advanced X-ray Astrophysics Facility (AXAF), is a Flagship-class space telescope launched aboard the during STS-93 by NASA on July 23, 1999. Chandra is sensitive to X-ray sources ...
, Herschel Space Observatory
The Herschel Space Observatory was a space observatory built and operated by the European Space Agency (ESA). It was active from 2009 to 2013, and was the largest infrared telescope ever launched until the launch of the James Webb Space Telesco ...
, Spitzer Space Telescope
The Spitzer Space Telescope, formerly the Space Infrared Telescope Facility (SIRTF), was an infrared space telescope launched in 2003. Operations ended on 30 January 2020. Spitzer was the third space telescope dedicated to infrared astronomy, f ...
ESA/Hubble
and the European Southern Observatory
The European Organisation for Astronomical Research in the Southern Hemisphere, commonly referred to as the European Southern Observatory (ESO), is an intergovernmental organization, intergovernmental research organisation made up of 16 mem ...
.[ESO Images in a Universal Context - Astronomical metadata to provide better access to space images](_blank)
/ref> Software packages such as PinpointWCS, FITS Liberator
The ESA/ ESO/NASA FITS (Flexible Image Transport System) Liberator is a free software program for processing and editing astronomical science data in the FITS format to reproduce images of the universe. Version 3 and later are standalone programs ...
FITS Liberator
/ref> and Microsoft WorldWide Telescope
WorldWide Telescope (WWT) is an open-source set of applications, data and cloud services, originally created by Microsoft Research but now an open source project hosted on GitHub. The .NET Foundation holds the copyright and the project is managed ...
have implemented the standard.
The metadata include information about the creator of the image, the content (including description and subject category), the method of observation (including facility, instrument and spectral information), the World Coordinate System (WCS) position in the sky, and the publisher of the image.
AVM was conceived by Robert Hurt, Lars Lindberg Christensen
Lars Lindberg Christensen is science communicator and author of a dozen books on astronomy and science communication translated to ten languages. He had a long career at ESO and is employed by NSF's NOIRLab and the International Astronomical ...
, and Adrienne Gauthier.
Metadata Categories
The Astronomy Visualization Metadata standard defines a taxonomy for astronomical objects.[ AVM 1.1 Final Candidate Appendix A](_blank)
/ref> The main categories are:
# Planet
# Interplanetary Body
# Star
# Nebula
# Galaxy
# Cosmology
# Sky Phenomenon
# Technology
# People
References
{{reflist
Digital photography
Metadata
Computational astronomy