Supported observatories are represented through a series of one-to-many relationships: an observatory has many telescopes, and a telescope can have many instruments. This generalized approach allows us to support a wide variety of observatory configurations, and has the flexibility to accommodate future additions and/or changes to supported missions.

The instrument model supports the following metadata:

• Field of View (FOV) Footprint — instruments with imaging capabilities can have their FOV represented as a list of polygon vertices. Upon data-ingestion, we accept a projected footprint for the instrument's observation FOV.
• Visibility Constraints — a list of observing constraints (e.g. sun angle, moon angle, Earth limb exclusion) used by the visibility calculator to determine when a target is observable by that instrument.
• Bandpass Filters — a list of filters describing the wavelength, energy, or frequency regimes the instrument can probe, covering both photometric (broadband filters) and spectroscopic (grisms, gratings) modes. Filter ranges are stored in Angstroms.

Similarly, observing schedules are represented as an aggregation of many observations over a continuous date range. A schedule can contain observations belonging to multiple instruments associated with the particular schedule's telescope.

Each observation can be described by:

• Observation type (spectroscopy, imaging, etc.)
• Target coordinates
• A date range for the exposure time
• Bandpass and filter information
• See full observation model response on API docs

There are current plans on providing a translation between this observation model and the IVOA ObsLocTAP standard in the near future.

Below are the assumptions for how we store physical representations of our data.

• All dates are stored in ISO format (YYYY-MM-DDTHH:MM:SSZ) in UTC timezone.
• All coordinates are stored in decimal degrees
• RA values between 0° and 360°
• Dec values between -90° and 90°
• All FOV polygons are stored as lists of vertices, where each vertex is a (RA, Dec) tuple in decimal degrees.
• All associated instrument filter (bandpass, grism) ranges are stored in Angstroms.