Quick reference for terms you'll encounter in POCS documentation and code.
pocs command
: The main command line tool for POCS. Run pocs --help to see all available commands.
pocs config setup : Interactive wizard to configure your PANOPTES unit. This should be the first command you run after installation.
pocs run auto : Starts POCS in fully automated mode for all-night observing. This is the main command for regular operations.
pocs mount : Group of commands for controlling the telescope mount (slew, park, home, etc.).
pocs camera : Group of commands for camera operations (take pictures, setup, etc.).
Simulator mode
: Running POCS with simulated hardware instead of real equipment. Enabled via configuration or CLI flags like --simulator mount.
PANOPTES : The project name. Stands for "Panoptic Astronomical Networked OPtical observatory for Transiting Exoplanets Survey". Basically: a network of robotic telescopes searching for planets.
POCS : PANOPTES Observatory Control System. The software that controls a PANOPTES telescope unit.
Observatory : In POCS, this means the software object that represents your complete telescope system (mount, cameras, dome, etc.), not the physical building.
Unit : A complete PANOPTES telescope system. Usually identified like "PAN001", "PAN012", etc.
Mount : The motorized base that points the telescope. It has two axes:
- RA (Right Ascension): East-West rotation
- Dec (Declination): North-South tilt
DSLR : Digital Single-Lens Reflex camera. PANOPTES often uses consumer cameras like Canon or Nikon.
Focuser : A motor that adjusts the camera focus by moving the lens or sensor.
Dome : A protective enclosure that opens for observing and closes for weather protection.
Filter Wheel : A rotating wheel with different color filters for specialized observations.
State Machine : A design pattern where software is always in one specific "state" and transitions between states following rules. Example states: sleeping, ready, observing.
Simulator : Fake hardware that lets you test POCS without physical equipment. Great for learning!
Config Server : A background service that provides configuration settings to POCS.
PANDIR
: Environment variable pointing to where POCS stores data. Usually /var/panoptes or ~/panoptes.
RA/Dec (Right Ascension / Declination) : Celestial coordinates. Like latitude/longitude but for the sky.
- RA: Measured in hours (0h to 24h)
- Dec: Measured in degrees (-90° to +90°)
Alt/Az (Altitude / Azimuth) : Local coordinates relative to your horizon.
- Altitude: Height above horizon (0° to 90°)
- Azimuth: Compass direction (0° to 360°)
Exoplanet : A planet orbiting a star other than our Sun.
Transit : When a planet passes in front of its star, causing a tiny dip in brightness. This is what PANOPTES looks for!
Exposure : A single photograph taken by the camera. Usually 30-60 seconds for PANOPTES.
Field of View (FOV) : How much sky the camera can see. Like the difference between a wide-angle and zoom lens.
Target : A star or region of sky that POCS is observing or planning to observe.
Observation : The complete process of observing one target: slewing, tracking, taking exposures, analyzing images.
Tags : String labels that can be attached to observations for categorization and searching (e.g., "exoplanet", "variable_star"). Tags are specified in field configuration files and stored in FITS headers.
Sequence : A series of exposures of the same target.
Pointing Model : Corrections to account for imperfections in mount alignment and mechanics.
Flat Field : Calibration images used to correct for dust and vignetting in the optical system.
Dark Frame : Calibration images with the shutter closed, used to remove sensor noise.
sleeping : Daytime state. POCS is waiting for darkness.
ready : Night has fallen and POCS is ready to start observing.
scheduling : Choosing which target to observe next.
slewing : Moving the telescope to point at a new target.
tracking : Verifying the mount is still tracking the target. The mount tracks continuously during observation, but this state checks it hasn't stopped (e.g., due to meridian or horizon limits).
observing : Taking photographs while the mount tracks the target.
analyzing : Checking image quality.
parking : Moving the telescope to a safe position at the end of the night.
parked : Telescope is in the safe position.
housekeeping : Performing maintenance tasks like data cleanup.
YAML : The file format used for configuration. It's like JSON but more human-readable.
pan_id : Your unit's identifier (e.g., "PAN001").
Constraint : A rule limiting what can be observed. Examples: minimum altitude, maximum airmass, moon avoidance.
Scheduler : The component that decides what to observe and when, considering constraints.
$PANDIR/images : Where POCS stores captured images.
$PANDIR/logs : Where POCS writes log files for debugging.
conf_files/ : Directory containing configuration YAML files.
state files : YAML files defining what happens in each state of the state machine.
from_config() : A class method that creates an object using settings from the config server.
Property
: In Python, a method that looks like a variable. Example: pocs.state (looks like a variable but is actually calling a method).
Callback : A function that gets called when something happens. Example: "Call this function when an image is ready."
Thread : A separate flow of execution. Allows POCS to do multiple things simultaneously (e.g., track and download images).
Process : Like a thread but more isolated. Used for camera control.
is_safe() : A method that checks if conditions are safe for observing (weather, sun position, etc.).
Safety Check
: One of several conditions evaluated by is_safe(). Examples: not daytime, weather OK, mount connected.
Ignore List : Safety checks that can be skipped (use carefully!).
can_observe : Overall flag indicating if the observatory is capable of observing.
Logger : The system that writes messages about what POCS is doing.
Log Level : How important a message is:
- DEBUG: Detailed info for developers
- INFO: General informational messages
- WARNING: Something unusual but not broken
- ERROR: Something failed
- CRITICAL: Severe problem
GHA: Greenwich Hour Angle LST: Local Sidereal Time UT/UTC: Universal Time / Coordinated Universal Time JD: Julian Date MJD: Modified Julian Date FITS: Flexible Image Transport System (astronomy image format) WCS: World Coordinate System (maps pixels to sky coordinates) SDK: Software Development Kit (vendor-provided software for hardware)
When reading code or documentation:
- If you see
self.logger.info(...), that's just writing a log message - If you see
@property, it's a method that looks like a variable - If you see
simulators=['all'], it means "use fake hardware" - If you see
assert, it's a safety check that stops if something is wrong
That's OK! You don't need to know all these terms to start using POCS. Learn them gradually as you encounter them.
Quick help:
- Ask on the forum: https://forum.projectpanoptes.org
- Check the docs: https://pocs.readthedocs.io
- Search the code:
grep -r "term_you_dont_know" src/
Remember: Every expert was once a beginner who kept asking questions! 🌟