ScienceCamera

class ctapointing.camera.ScienceCamera(**kwargs: Any)

Bases: Component

CTA Science camera class.

Stores information about the focal plane of the camera, its distance from the mirror dish, and the position of pointing LEDs. Provides a method to transform sky coordinates into positions on the planar focal plane.

Attributes Summary

`body_intensity`	intensity of camera body (for simulations)
`body_vertex_positions`
`body_vertex_positions_x`	x coordinate of vertices defining body outer dimensions (for simulations, in camera frame)
`body_vertex_positions_y`	y coordinate of vertices defining body outer dimensions (for simulations, in camera fram)
`centre`	Return the centre of the camera in the ScienceCameraFrame
`focal_length`	focal length of mirror dish
`led_intensity`	LED intensities (for simulations)
`led_positions`	Return the camera LED positions in the ScienceCameraFrame
`led_positions_x`	LED positions (x coordinate) in camera frame
`led_positions_y`	LED positions (y coordinate) in camera frame
`led_radius`	radius of the LED pinholes (for simulations)
`lid_intensity`	intensity of camera lid (for simulations)
`lid_radius`	radius of circular camera lid
`manufacturer`	camera manufacturer
`mirror_area`	effective area of mirror dish
`model`	camera model
`name`	camera name
`offset`	offset of camera centre w.r.t.
`rotation`	rotation of camera w.r.t.
`sciencecameraframe`	Return a ScienceCameraFrame object, initialised from current camera (focal length, rotations, tilts etc.) properties.
`tilt`	camera tilt w.r.t.
`uuid`	UUID of Camera

Methods Summary

`from_config`(**kwargs)	Read a camera configuration from either configuration file or database.
`project_from`(coords, obstime, telescope_pointing)	Project given SkyCameraFrame coordinates back to AltAz.
`project_into`(coords[, telescope_pointing])	Project a given array of altaz coordinates into the science camera frame.

Attributes Documentation

body_intensity: intensity of camera body (for simulations)

body_vertex_positions

body_vertex_positions_x: x coordinate of vertices defining body outer dimensions (for simulations, in camera frame)

body_vertex_positions_y: y coordinate of vertices defining body outer dimensions (for simulations, in camera fram)

centre: Return the centre of the camera in the ScienceCameraFrame

focal_length: focal length of mirror dish

led_intensity: LED intensities (for simulations)

led_positions: Return the camera LED positions in the ScienceCameraFrame

led_positions_x: LED positions (x coordinate) in camera frame

led_positions_y: LED positions (y coordinate) in camera frame

led_radius: radius of the LED pinholes (for simulations)

lid_intensity: intensity of camera lid (for simulations)

lid_radius: radius of circular camera lid

manufacturer: camera manufacturer

mirror_area: effective area of mirror dish

model: camera model

name: camera name

offset: offset of camera centre w.r.t. telescope orientation (x/y)

rotation: rotation of camera w.r.t. horizon, in degrees

sciencecameraframe

Return a ScienceCameraFrame object, initialised from current camera (focal length, rotations, tilts etc.) properties.

Can be used to transform from/to SciemceCameraFrame using up-to-date transformation parameters.

tilt: camera tilt w.r.t. telescope orientation (x/y)

uuid: UUID of Camera

Methods Documentation

classmethod from_config(**kwargs)

Read a camera configuration from either configuration file or database. Either the path of a configuration file (‘input_url’) or a database collection (‘collection’) must be provided.

Parameters:

input_url (str or Path) – path of the configuration file.
name (str) – name of the camera (as in ScienceCamera.name). When loading the configuration from file, can be set to check that the configuration with the correct name is loaded. When loading from database, is used to identify the correct database record.
uuid (str) – UUID of the camera (as in ScienceCamera.uuid). When loading the configuration from file, can be set to check that the configuration with the correct UUID is loaded. When loading from database, is used to identify the correct database record.
collection (str) – name of the database collection from which configuration is read
database (str) – name of the database in which the collection is stored

Returns:

camera

Return type:

ScienceCamera object

project_from(coords, obstime, telescope_pointing)

Project given SkyCameraFrame coordinates back to AltAz.

Parameters:

coords (SkyCoord in SkyCameraFrame) – coordinates on CCD chip in SkyCameraFrame
obstime (Astropy.Time) – time of the observation
telescope_pointing (SkyCoord) – telescope pointing direction

Returns:

coords_altaz – transformed coordinates in the AltAz system

Return type:

SkyCoord

project_into(coords, telescope_pointing=None)

Project a given array of altaz coordinates into the science camera frame. Takes current camera orientation and tilts into account.

Parameters:

coords (array(astropy.SkyCoord)) – array of sky coordinates in the AltAz system
telescope_pointing (astropy.SkyCoord) – telescope pointing position (RADec or AltAz system)

Returns:

coords_proj (SkyCoord) – 2D projections in chip coordinates (in ScienceCameraFrame)
todo (star projection is wrong when translation t is switched on. This happens because)
the altaz position of the (infinitely) distant star is converted to a vector on the
unit circle. Should explicitly distinguish between star projection and projection of
world objects.

__init__(config=None, parent=None, **kwargs)

Parameters:

config (traitlets.loader.Config) – Configuration specified by config file or cmdline arguments. Used to set traitlet values.
parent (Tool or Component) – If a Component is created by another Component or Tool, you need to pass the creating Component as parent, e.g. parent=self. This makes sure the config is correctly handed down to the child components. Do not pass config in this case.
kwargs – Traitlets to be overridden. TraitError is raised if kwargs contains a key that does not correspond to a traitlet.

body_intensity: intensity of camera body (for simulations)

body_vertex_positions_x: x coordinate of vertices defining body outer dimensions (for simulations, in camera frame)

body_vertex_positions_y: y coordinate of vertices defining body outer dimensions (for simulations, in camera fram)

property centre: Return the centre of the camera in the ScienceCameraFrame

focal_length: focal length of mirror dish

classmethod from_config(**kwargs)

Read a camera configuration from either configuration file or database. Either the path of a configuration file (‘input_url’) or a database collection (‘collection’) must be provided.

Parameters:

input_url (str or Path) – path of the configuration file.
name (str) – name of the camera (as in ScienceCamera.name). When loading the configuration from file, can be set to check that the configuration with the correct name is loaded. When loading from database, is used to identify the correct database record.
uuid (str) – UUID of the camera (as in ScienceCamera.uuid). When loading the configuration from file, can be set to check that the configuration with the correct UUID is loaded. When loading from database, is used to identify the correct database record.
collection (str) – name of the database collection from which configuration is read
database (str) – name of the database in which the collection is stored

Returns:

camera

Return type:

ScienceCamera object

led_intensity: LED intensities (for simulations)

property led_positions: Return the camera LED positions in the ScienceCameraFrame

led_positions_x: LED positions (x coordinate) in camera frame

led_positions_y: LED positions (y coordinate) in camera frame

led_radius: radius of the LED pinholes (for simulations)

lid_intensity: intensity of camera lid (for simulations)

lid_radius: radius of circular camera lid

manufacturer: camera manufacturer

mirror_area: effective area of mirror dish

model: camera model

name: camera name

offset: offset of camera centre w.r.t. telescope orientation (x/y)

project_from(coords, obstime, telescope_pointing)

Project given SkyCameraFrame coordinates back to AltAz.

Parameters:

coords (SkyCoord in SkyCameraFrame) – coordinates on CCD chip in SkyCameraFrame
obstime (Astropy.Time) – time of the observation
telescope_pointing (SkyCoord) – telescope pointing direction

Returns:

coords_altaz – transformed coordinates in the AltAz system

Return type:

SkyCoord

project_into(coords, telescope_pointing=None)

Project a given array of altaz coordinates into the science camera frame. Takes current camera orientation and tilts into account.

Parameters:

coords (array(astropy.SkyCoord)) – array of sky coordinates in the AltAz system
telescope_pointing (astropy.SkyCoord) – telescope pointing position (RADec or AltAz system)

Returns:

coords_proj (SkyCoord) – 2D projections in chip coordinates (in ScienceCameraFrame)
todo (star projection is wrong when translation t is switched on. This happens because)
the altaz position of the (infinitely) distant star is converted to a vector on the
unit circle. Should explicitly distinguish between star projection and projection of
world objects.

rotation: rotation of camera w.r.t. horizon, in degrees

property sciencecameraframe

Return a ScienceCameraFrame object, initialised from current camera (focal length, rotations, tilts etc.) properties.

Can be used to transform from/to SciemceCameraFrame using up-to-date transformation parameters.

tilt: camera tilt w.r.t. telescope orientation (x/y)

uuid: UUID of Camera