Tools & Code
In addition to ingested observatory scheduling data, a set of ACROSS observing tools is available to aid in TDAMM observing endeavors — accessible both as interactive web-based portals and as open-source Python packages.
Web Tools
Visibility Calculator
The Joint Visibility Calculator allows users to determine when a celestial target is simultaneously observable by one or more selected telescope–instrument combinations.
Given a target position (RA/Dec in J2000) and a date range, the tool computes:
- Joint Visibility Windows — time intervals during which all selected instruments can observe the target concurrently
- Per-Instrument Visibility Windows — individual observability windows broken down by instrument
Query parameters include:
- Target Coordinates — RA and Dec (J2000 decimal degrees); an object name resolver is provided for convenience
- Instrument Selection — one or more observatory / telescope / instrument combinations
- Date Range — the time window over which to calculate visibility
Visibility Constraints
Each instrument carries its own set of observing constraints that are applied during the calculation. Typical constraints include:
- Earth Limb Exclusion — minimum elevation angle above the Earth's limb for space-based observatories
- Sun Avoidance — minimum angular separation between the target and the Sun
- Moon Avoidance — minimum angular separation between the target and the Moon
- SAA Avoidance — exclusion of passes through the South Atlantic Anomaly for affected missions
- Altitude / Azimuth Limits — minimum elevation above the horizon and azimuth range restrictions for ground-based observatories
Query Portals
ACROSS provides interactive web-based portals for querying and exploring data directly in the browser.
Schedules
Query observing schedules across all supported missions. Results can be filtered by the following parameters:
- Observatory / Telescope / Instrument — filter results to one or more specific instruments
- Date Range — narrow results to schedules that overlap a given time window
- Schedule Type — filter by planned, executed, or other schedule states
Each schedule in the results links through to its constituent observations, allowing you to drill down from a high-level schedule view into the individual pointings and exposure details that make it up.
Observations
Query individual observations ingested from supported mission schedules. Available filter parameters include:
- Observatory / Telescope / Instrument — scope results to a specific instrument
- Date Range — filter by the start or end time of the observation exposure
- Observation Type — filter by mode such as imaging or spectroscopy
- Coordinates & Search Radius — find observations targeting a specific sky position
Python Libraries
across-tools
A lightweight astronomy observing Python package that provides functionality for:
- Ephemeris Based Visibility Calculation
- Spherical Polygon Analysis — for instrument footprints
- Bandpass Converter
across-client
An API client package that wraps all astronomy observing related API endpoints, while providing resource methods for the aforementioned across-tools package on the API results.