This is a webform which allows a user to compute the sky footprint of a Telescope/Detector combination for a specified pointing and

The footprint computation requires the ra,dec pointing for the center of the telescope focal plane (V1 axis), as well as the roll angle of the telescope. All of these parameters are specified in decimal degrees.

We have a partial implementation of telescopes/detector combinations. Currently we support some of the most used HST instrument apertures and the Roman Wide Field Imager (as currently defined January 2020). Additional instrument/apertures can be added if requested.

When returning data to the user it is possible to select a number of different formats

We have a small subset of our catalogs available with the necessary metadata added to support this function.

It is also possible to programatically call this webservice to retrieve footprint or catalog data for analysis using the endpoint
http://gsss.stsci.edu/webservices/footprints/FootprintService.aspx?tele=value&inst=value&aper=value&ra=value&dec=value&pa=value&format=value[&catalog=value]
e.g. http://gsss.stsci.edu/webservices/footprints/FootprintService.aspx?TELE=ROMAN&INST=WFI&APER=WFI&RA=120.0&DEC=45.0&PA=60.0&FORMAT=HTML&CAT=2MASS
The values are as listed in the webform interface. If the CAT parameter is not present, the service will return the footprint boundary in VO standard Space-Time-Coordinate (STC) format. If the CAT parameter is present it will return the catalog data. Optional parameters when returning the catalog are a magnitude range (e.g. MAGRANGE=12.5,13.7) and the maximum number of objects to return (e.g. MAXOBJ=5000 will return the brightest 5000 objects selected)

Main limitations at the moment are the portal API

All of these features will be improved in coming months - please email the archive helpdesk for additional help or requests