Welcome to the National Virtual Observatory's web portal at the Johns Hopkins University dedicated to the footprints of astronomy observations. Everything you would ever want to know about the deepest fields or the largest surveys starts here with their coverage on the sky. Here is just a few things you could do on these pages right now:

Search for the coverage and exact area of a specific survey by its name or a given position. Find quickly all observations that cover all your favorite objects...
Create the formal description of your own obser­vations and calculate the exact area of the over­lapping fields in seconds. It really is simple here.
Visualize the sky coverage of multiple surveys from different angles and in various projections. Check out our marvellous stereographic projection on the right.
Intersect various footprints and derive the common area. Estimate the number of galaxies or stars with measurements in all surveys or look for the dropouts.
Download any footprints in various formats including ASCII and the IVOA standard Space Time Coordinate region specification for querying other VO resources.
Publish the coverage of your observations in the Virtual Observatory framework simply by saving it from the editor into My Footprints.
Program our web services if you need to do more.

Acknowledging Us

Users are asked to acknowledge their use of NVO tools, applications, and software in any re­sult­ing pub­lications. The following language is sug­gested:

This research has made use of data obtained from or software provided by the US National Virtual Observatory, which is sponsored by the National Sci­ence Foundation.

We further kindly request that you include, at the first mention of Footprint Services,
a footnote placed in the main body of the paper referring to the web site located at http://www.voservices.net/footprint and a reference to the following paper

Budavári, T., Dobos, L., Szalay, A.S., Greene, G., Gray, J., Rots, A. H., 2007, "Footprint Services for Everyone" in Astronomical Data Analysis Software and Systems XVI, ASP Conference Series, Vol. 376, eds. R. A. Shaw, F. Hill & D. J. Bell (San Francisco: ASP), p.559