The Area layer control ()
allows you to plot a two-dimensional shape from each row of a table.
This might typically be something like an instrument coverage footprint
corresponding to an observation.
The shape may be specified in various different ways:
as an STC-S region specification string
(as found for instance in the
s_region
column of
ObsCore or EPN-TAP query results),
as an array specification of polygons or circles,
or as an ASCII-encoded MOC.
You can add one of these controls to the stack by using the
Add Area Control () button
in the control panel toolbar
or the corresponding item in the Layers menu
for suitable plot types
(Plane,
Sky or
Sphere).
Areas specified in this way are generally intended for displaying relatively small shapes such as instrument footprints. Larger areas may also be specified, but there may be issues with use, for instance auto-determination of the initial plot region may not work so well, and the rendering of shapes that are large relative to the sky may be inaccurate. These issues may be addressed in future releases.
Sky Plot Window with an Area control
This control is a Table Data control as described in Appendix A.4.2.2. That section explains the Subsets tab; the Position and Form tabs are described in more detail below.