Classes

A reference for the documentation of all user class objects.

Module

class scanning.camera.Module(data=None, units=None, **kwargs)[source]

Class for a single camera module (e.g. EoRSpec, CMBPol, SFH). Each module consists of three wafers/detector arrays. Each wafter contains three rhombuses.

__init__(data=None, units=None, **kwargs) → None[source]

Create a camera module either through:: option1 : Module(data, units)

option2 : Module(freq=, F_lambda=)

option3 : Module(wavelength=, F_lambda=)

Parameters

data (str, DataFrame or [dict of str -> sequence]) – If str, a file path to a csv file. If dict or DataFrame, column names map to their values. Must have columns: x, y. Recommended to have columns: pol, rhombus, and wafer.
units ([dict of str -> str or Unit] or None; default None) – Mapping columns in data with their units. All columns do not need to be mapped. If not provided, all applicable units are assumed to be in degrees.

Keyword Arguments

freq (float, Quantity or str; default unit GHz) – Center of frequency band. Must be positive. If each wafer is different (such as EoRSpec), pass a three-length list like [freq1, freq2, freq3].
wavelength (float, Quantity or str; default unit micron) – Intended wavelength of light. Must be positive. If each wafer is different (such as EoRSpec), pass a three-length list like [wavelength1, wavelength2, wavelength3].
F_lambda (float; default 1.2) – Factor for spacing between individual detectors.

Raises

ValueError – data could not be properly interpreted.
TypeError – Missing parameters or unneccesary keywords.

Examples

>>> Module('file.csv', units={'x': 'arcsec'}) # specify x is in arcsec
>>> Module(freq=280, F_lambda=1.2)
>>> Module(wavelength='350 micron')

save_data(path_or_buf=None, columns='all')[source]

Write Module object to csv file.

Parameters

path_or_buf (str, file handle or None; default None) – File path or object, if None is provided the result is returned as a dictionary.
columns (sequence, str or [dict of str -> str/Unit/None]; default 'all') – Columns to write. If dict, map column names to their desired unit and use None if column is unit-less. ‘all’ is [‘x’, ‘y’, ‘pol’, ‘pixel_num’, ‘rhombus’, ‘wafer’]

Returns

If path_or_buf is None, returns the data as a dictionary mapping column name to values. Otherwise returns None.

Return type

None or [dict of str -> array]

Examples

>>> # saves x, y, and rhombus
>>> module.save_data(path_or_buf='file.csv', columns={'x': 'arcsec', 'y': 'rad', 'rhombus': None})

property F_lambda

F lambda.

Type: Quantity

property ang_res

Angular resolution. If multiple frequencies or wavelengths were provided, this will be a three-length sequence.

Type: Quantity or Quantity array

property freq

Center of frequency band. If multiple frequencies or wavelengths were provided, this will be a three-length sequence.

Type: Quantity or Quantity array

property pixel_num

Pixel mumber.

Type: int array

property pol

Polarization geometry.

Type: Quantity array

property rhombus

Rhombus number.

Type: int array

property wafer

Wafer number.

Type: int array

property x

x offset of detector pixels.

Type: Quantity array

property y

y offset of detector pixels

Type: Quantity array

Instrument

class scanning.camera.Instrument(data=None, instr_offset=(0, 0), instr_rot=0)[source]

A configurable instrument that holds modules.

__init__(data=None, instr_offset=(0, 0), instr_rot=0) → None[source]

Initialize a filled Instrument:: option 1: Instrument(data)
or an empty Intrument:: option 2: Instrument(instr_offset, instr_rot)

Parameters

data (str or dict) – File path to json file or dict object. Overwrites instr_offset and instr_rot. Applicable values are in degrees unit.
instr_offset ((float/Quantity/str, float/Quantity/str); default (0, 0), default unit deg) – Offset of the instrument from the boresight.
instr_rot (float, Quantity or str; default 0, default unit deg) – CCW rotation of the instrument.

Raises

ValueError – could not parse “data”

Examples

>>> import astropy.units as u
>>> Instrument(inst_offset=(0, '100 arcsec'), instr_rot=3.14*u.rad)
>>> Instrument('file.json')

add_module(module, location, mod_rot=0, identifier=None) → None[source]

Add a module to the instrument.

Parameters

module (Module or str) – A Module object or one of the default options [‘CMBPol’, ‘SFH’, ‘EoRSpec’, ‘Mod280’]
location ((float/Quantity/str, float/Quantity/str) or str; default unit deg) – A tuple containing the (distance, theta) from the center of the instrument in polar coordinates. Or a str of one of the default slot options.
identifier (str or None) – Name of the module. If user chose a default module option and this is None, then identifier will be its corresponding name.
mod_rot (float/Quantity/str; default 0, default unit deg) – CCW rotation of the module.

change_module(identifier, new_location=None, new_mod_rot=None, new_identifier=None) → None[source]

Change a module in the instrument.

Parameters

identifier (str) – Name of the module to change.
new_location ((float/Quantity/str, float/Quantity/str) or str; default unit deg, optional) – A tuple containing the (distance, theta) from the center of the instrument in polar coordinates. Or a str of one of the default slot options.
new_mod_rot (float/Quantity/str; default 0, default unit deg, optional) – CCW rotation of the module.
new_identifier (str, optional, optional) – New name of the module.

Raises

ValueError – “identifier” is not valid

delete_module(identifier) → None[source]

Delete a module in the instrument.

Parameters: identifier (str) – Name of the module.
Raises: ValueError – “identifier” is not valid

get_module(identifier, with_mod_rot=False, with_instr_rot=False, with_instr_offset=False, with_mod_offset=False) → scanning.camera.Module[source]

Parameters

identifier (str) – Name of the module.
with_mod_rot (bool; default False) – Whether to apply instrument and module rotation and offset to the returned Module.
with_instr_rot (bool; default False) – Whether to apply instrument and module rotation and offset to the returned Module.
with_instr_offset (bool; default False) – Whether to apply instrument and module rotation and offset to the returned Module.
with_mod_offset (bool; default False) – Whether to apply instrument and module rotation and offset to the returned Module.

Returns

Module object.

Return type

Module

Raises

ValueError – “identifier” is not valid

get_module_dist(identifier, from_boresight=False)[source]

Parameters

identifier (str) – Name of the module.
from_boresight (bool; default False) – From the boresight (True) or from the center of the instrument (False).

Returns

Distance away of the module in polar coordinates.

Return type

Quantity

Raises

ValueError – “identifier” is not valid

get_module_location(identifier, from_boresight=False, polar=True)[source]

Parameters

identifier (str) – Name of the module.
from_boresight (bool; default False) – From the boresight (True) or from the center of the instrument (False).
polar (bool; default True) – In polar coordinates (True) or in cartesian coordinates (False)

Returns

(distance, theta) location of module.

Return type

Quantity two-tuple

Raises

ValueError – “identifier” is not valid

get_module_rot(identifier, with_instr_rot=False)[source]

Get rotation of module from the center of the instrument.

Parameters

identifier (str) – Name of the module.
with_instr_rot (bool; default False) – Whether to include instrument rotation.

Returns

Rotation of the module

Return type

Quantity

Raises

ValueError – “identifier” is not valid

get_module_theta(identifier, from_boresight=False)[source]

Parameters

identifier (str) – Name of the module.
from_boresight (bool; default False) – From the boresight (True) or from the center of the instrument (False).

Returns

Angle of the module in polar coordinates.

Return type

Quantity

Raises

ValueError – “identifier” is not valid

get_slot_location(slot_name, from_boresight=False, polar=True)[source]

Parameters

slot_name (str) – Name of slot.
from_boresight (bool; default False) – From the boresight (True) or from the center of the instrument (False).
polar (bool; default True) – In polar coordinates (True) or in cartesian coordinates (False)

Returns

(distance, theta) location of slot.

Return type

Quantity two-tuple

Raises

ValueError – “slot_name” is not valid

location_from_boresight(dist, theta, polar=True)[source]

Given a location relative to the center of the instrument, find the location relative to the boresight.

Parameters

dist (float, Quantity, or str; default unit deg) – Distance away from the center of the instrument.
theta (float, Quantity, or str; default unit deg) – Angle away from the center of the instrument in polar coordinates.
polar (bool; default True) – In polar coordinates (True) or in cartesian coordinates (False)

Returns

(distance, theta) location of slot.

Return type

Quantity two-tuple

save_data(path_or_buf=None)[source]

Saves as a dictionary like in a json format.

Parameters: path_or_buf (str or file handle, default None) – File path or object, if None is provided the result is returned as a dict.
Returns: If path_or_buf is None, returns the resulting json format as a dictionary. Otherwise returns None.
Return type: None or dict

property instr_offset

The x and y offsets of the center of the instrument from the boresight.

Type: Quantity two-tuple

property instr_rot

The CCW rotation of the instrument.

Type: Quantity

property modules

list of module identifiers inside the instrument.

Type: list of str

property slots

Map of slot name to their (distance, theta) from the center of the instrument.

Type: dict of str -> Quantity two-tuple

PrimeCam

A subclass of the Instrument class. The only major difference are the slot locations, so inherited members are not listed.

class scanning.camera.PrimeCam(data=None, instr_offset=(0, 0), instr_rot=0)[source]

ModCam

A subclass of the Instrument class. The only major difference are the slot locations, so inherited members are not listed.

class scanning.camera.ModCam(data=None, instr_offset=(0, 0), instr_rot=0)[source]

SkyPattern

class scanning.coordinates.SkyPattern(data, units=None, repeatable=False, **kwargs)[source]

Representing the path of the center of a detector array in terms of offsets.

__init__(data, units=None, repeatable=False, **kwargs) → None[source]

Parameters

data (str, DataFrame, or [dict of str -> sequence]) – If str, a file path to a csv file. If dict or DataFrame, column names map to their values. Must have columns ‘time_offset’, ‘x_coord’, ‘y_coord’.
repeatable (bool; default False) – Whether this pattern can repeat itself (ends where it starts).
units ([dict of str -> str or Unit] or None; default None) – Mapping columns in data with their units. All columns do not need to be mapped. If not provided, all angle-like units are assumed to be in degrees and all time-like units are assumed to be in seconds.

Keyword Arguments

num_repeat (int; default 1) – Number of repeats of the pattern. Must be a positive integer. Cannot be used with max_scan_duration and repeatable must be True.
max_scan_duration (float/Quantity/str; default unit sec) – Maximum total scan time to determine number of repeats. Must be positive. Cannot be used with num_repeat and repeatable must be True.

Raises

ValueError – “data” could not be parsed
ValueError – sample interval must be constant

Examples

>>> # if x_coord is specifically in arcseconds
>>> SkyPattern('file.csv', units={'x_coord': 'arcsec'})

save_data(path_or_buf=None, columns='default', include_repeats=True)[source]

Parameters

path_or_buf (str, file handle or None; default None) – File path or object, if None is provided the result is returned as a dictionary.
columns (sequence, str or [dict of str -> str/Unit/None]; default 'default') – Columns to write. If dict, map column names to their desired unit and use None if you would like to use the standard (deg for angle-like units, sec for time-like units). ‘default’ for [‘time_offset’, ‘x_coord’, ‘y_coord’] ‘all’ for [‘time_offset’, ‘x_coord’, ‘y_coord’, ‘distance’, ‘x_vel’, ‘y_vel’, ‘vel’, ‘x_acc’, ‘y_acc’, ‘acc’, ‘x_jerk’, ‘y_jerk’, ‘jerk’]
include_repeats (bool, default 'True') – Whether to include repeats of the SkyPattern.

Returns

If path_or_buf is None, returns the data as a dictionary mapping column name to values. Otherwise returns None.

Return type

None or [dict of str -> array]

Examples

>>> skypattern.save_data('file.csv', columns={'time_offset': 's', 'x_coord': 'arcsec', 'y_coord': None})

save_param(path_or_buf=None)[source]

Parameters: path_or_buf (str, file handle, or None; default None) – File path or object, if None is provided the result is returned as a dictionary.
Returns: If path_or_buf is None, returns the resulting json format as a dictionary. Otherwise returns None.
Return type: None or [dict of str -> numeric]

property acc

Total acceleration.

Type: Quantity array

property distance

Distance of points from the center.

Type: Quantity array

property jerk

Total jerk.

Type: Quantity array

property param

Parameters inputted by user.

Type: dict of str -> (float or Quantity)

property repeatable

Whether this pattern is repeatable or not.

Type: bool

property sample_interval

Time interval between samples.

Type: Quantity

property scan_duration

Total scan duration.

Type: Quantity

property time_offset

Time offsets.

Type: Quantity array

property vel

Total velocity.

Type: Quantity array

property x_acc

x acceleration.

Type: Quantity array

property x_coord

x positions.

Type: Quantity array

property x_jerk

x jerk.

Type: Quantity array

property x_vel

x velocity.

Type: Quantity array

property y_acc

y acceleration.

Type: Quantity array

property y_coord

y positions.

Type: Quantity array

property y_jerk

y jerk.

Type: Quantity array

property y_vel

y velocity.

Type: Quantity array

Pong

A subclass of the SkyPattern object. Inherited members are listed.

class scanning.coordinates.Pong(param_json=None, **kwargs)[source]

The Curvy Pong pattern allows for an approximation of a Pong pattern while avoiding sharp turnarounds at the vertices. The Pong pattern is an analytic and close-pathed pattern that is optimized for regions a few square degrees. It makes a path that intends to cover each area uniformly and ends where it starts.

See “The Impact of Scanning Pattern Strategies on Uniform Sky Coverage of Large Maps” (SCUBA Project SC2/ANA/S210/008) for details of implementation.

__init__(param_json=None, **kwargs) → None[source]

Initialize a Pong pattern by passing a parameter file and overwriting any parameters with **kwargs:: option1 : Pong(param_json, **kwargs)
or building from scratch:: option2 : Pong(**kwargs)

Parameters

param_json (str or None) – If str path to JSON file containing parameters.

Keyword Arguments

num_term (int) – Number of terms in the triangle wave expansion. Must be positive.
width (float or Quantity or str; default unit deg) – Width of the field. Must be positive.
height (float or Quantity or str; default unit deg) – Height of the field. Must be positive.
spacing (float or Quantity or str; default unit deg) – Space between adjacent (parallel) scan lines in the Pong pattern. Must be positive.
velocity (float or Quantity or str; default unit deg/s) – Target magnitude of the total scan velocity excluding turn-arounds. NOTE this is now the total velocity, not just the velocity of one direction.
angle (float or Quantity or str; default 0; default unit deg) – Position angle of the box in the native coordinate system.
sample_interval (float or Quantity or str; default 1/400, default unit s) – Time between read-outs. Must be positive.
num_repeat (int; default 1) – Number of repeats of the pattern. Must be a positive integer. Cannot be used with max_scan_duration.
max_scan_duration (float or Quantity or str; default unit sec) – Maximum total scan time to determine number of repeats. Must be positive. Cannot be used with num_repeat.

Examples

>>> import astropy.units as u
>>> Pong(num_term=4, width=2, height=7200*u.arcsec, spacing='500 arcsec', velocity=1/2)

save_data(path_or_buf=None, columns='default', include_repeats=True)

Parameters

path_or_buf (str, file handle or None; default None) – File path or object, if None is provided the result is returned as a dictionary.
columns (sequence, str or [dict of str -> str/Unit/None]; default 'default') – Columns to write. If dict, map column names to their desired unit and use None if you would like to use the standard (deg for angle-like units, sec for time-like units). ‘default’ for [‘time_offset’, ‘x_coord’, ‘y_coord’] ‘all’ for [‘time_offset’, ‘x_coord’, ‘y_coord’, ‘distance’, ‘x_vel’, ‘y_vel’, ‘vel’, ‘x_acc’, ‘y_acc’, ‘acc’, ‘x_jerk’, ‘y_jerk’, ‘jerk’]
include_repeats (bool, default 'True') – Whether to include repeats of the SkyPattern.

Returns

If path_or_buf is None, returns the data as a dictionary mapping column name to values. Otherwise returns None.

Return type

None or [dict of str -> array]

Examples

>>> skypattern.save_data('file.csv', columns={'time_offset': 's', 'x_coord': 'arcsec', 'y_coord': None})

save_param(path_or_buf=None)

Parameters: path_or_buf (str, file handle, or None; default None) – File path or object, if None is provided the result is returned as a dictionary.
Returns: If path_or_buf is None, returns the resulting json format as a dictionary. Otherwise returns None.
Return type: None or [dict of str -> numeric]

property acc

Total acceleration.

Type: Quantity array

property distance

Distance of points from the center.

Type: Quantity array

property jerk

Total jerk.

Type: Quantity array

property param

Parameters inputted by user.

Type: dict of str -> (float or Quantity)

property repeatable

Whether this pattern is repeatable or not.

Type: bool

property sample_interval

Time interval between samples.

Type: Quantity

property scan_duration

Total scan duration.

Type: Quantity

property time_offset

Time offsets.

Type: Quantity array

property vel

Total velocity.

Type: Quantity array

property x_acc

x acceleration.

Type: Quantity array

property x_coord

x positions.

Type: Quantity array

property x_jerk

x jerk.

Type: Quantity array

property x_vel

x velocity.

Type: Quantity array

property y_acc

y acceleration.

Type: Quantity array

property y_coord

y positions.

Type: Quantity array

property y_jerk

y jerk.

Type: Quantity array

property y_vel

y velocity.

Type: Quantity array

Daisy

A subclass of the SkyPattern object. Inherited members are listed.

class scanning.coordinates.Daisy(param_json=None, **kwargs)[source]

The Daisy pattern is optimized for point sources and works by having the path of the camera module move at constant velocity and cross the center of the map at various angles.

See “CV Daisy - JCMT small area scanning pattern” (JCMT TCS/UN/005) for details of implementation.

__init__(param_json=None, **kwargs) → None[source]

Initialize a Daisy pattern by passing a parameter file and overwriting any parameters with **kwargs:: option1 : Daisy(param_json, **kwargs)
or building from scratch:: option2 : Daisy(**kwargs)

Parameters

param_json (str or None) – If str path to JSON file containing parameters.

Keyword Arguments

velocity (float or Quanity or str; default unit deg/s) – Constant velocity (CV) for scan to go at.
start_acc (float or Quanity or str; default unit deg/s^2) – Acceleration at start of pattern. Cannot be 0.
R0 (float or Quanity or str; default unit deg) – Radius R0. Must be positive.
Rt (float or Quanity or str; default unit deg) – Turn radius. Must be positive.
Ra (float or Quanity or str; default unit deg) – Avoidance radius. Must be non-negative.
T (float or Quanity or str; default unit sec) – Total time of the simulation. Must be postivie.
sample_interval (float or Quanity or str; default 1/400, default unit sec) – Time step.
y_offset (float or Quanity or str; default 0, default unit deg) – Start offset in y.

Examples

>>> import astropy.units as u
>>> Daisy(velocity=1/3*u.deg/u.s, start_acc='0.2 deg/s/s', R0=0.47, Rt=800*u.arcsec, Ra='600 arcsec', T=300)

save_data(path_or_buf=None, columns='default', include_repeats=True)

Parameters

path_or_buf (str, file handle or None; default None) – File path or object, if None is provided the result is returned as a dictionary.
columns (sequence, str or [dict of str -> str/Unit/None]; default 'default') – Columns to write. If dict, map column names to their desired unit and use None if you would like to use the standard (deg for angle-like units, sec for time-like units). ‘default’ for [‘time_offset’, ‘x_coord’, ‘y_coord’] ‘all’ for [‘time_offset’, ‘x_coord’, ‘y_coord’, ‘distance’, ‘x_vel’, ‘y_vel’, ‘vel’, ‘x_acc’, ‘y_acc’, ‘acc’, ‘x_jerk’, ‘y_jerk’, ‘jerk’]
include_repeats (bool, default 'True') – Whether to include repeats of the SkyPattern.

Returns

If path_or_buf is None, returns the data as a dictionary mapping column name to values. Otherwise returns None.

Return type

None or [dict of str -> array]

Examples

>>> skypattern.save_data('file.csv', columns={'time_offset': 's', 'x_coord': 'arcsec', 'y_coord': None})

save_param(path_or_buf=None)

Parameters: path_or_buf (str, file handle, or None; default None) – File path or object, if None is provided the result is returned as a dictionary.
Returns: If path_or_buf is None, returns the resulting json format as a dictionary. Otherwise returns None.
Return type: None or [dict of str -> numeric]

property acc

Total acceleration.

Type: Quantity array

property distance

Distance of points from the center.

Type: Quantity array

property jerk

Total jerk.

Type: Quantity array

property param

Parameters inputted by user.

Type: dict of str -> (float or Quantity)

property repeatable

Whether this pattern is repeatable or not.

Type: bool

property sample_interval

Time interval between samples.

Type: Quantity

property scan_duration

Total scan duration.

Type: Quantity

property time_offset

Time offsets.

Type: Quantity array

property vel

Total velocity.

Type: Quantity array

property x_acc

x acceleration.

Type: Quantity array

property x_coord

x positions.

Type: Quantity array

property x_jerk

x jerk.

Type: Quantity array

property x_vel

x velocity.

Type: Quantity array

property y_acc

y acceleration.

Type: Quantity array

property y_coord

y positions.

Type: Quantity array

property y_jerk

y jerk.

Type: Quantity array

property y_vel

y velocity.

Type: Quantity array

TelescopePattern

class scanning.coordinates.TelescopePattern(data, instrument=None, data_loc='boresight', obs_param=None, units=None, **kwargs)[source]

Representing the path in AZ/EL coordinates of the telescope’s boresight.

__init__(data, instrument=None, data_loc='boresight', obs_param=None, units=None, **kwargs) → None[source]

Determine the motion of the telescope. Note that **kwargs can be passed as a file through obs_param.: option1: data (sky), instrument (optional), data_loc (optional); lat, start_ra, start_dec, (start_datetime or start_hrang or start_lst or [start_elev and moving_up])

option2: data (telescope, excludes lst), instrument (optional), data_loc (optional); lat, (start_ra or start_datetime or start_lst)

option3: data (telescope, includes lst), instrument (optional), data_loc (optional); lat

Parameters

data (str, DataFrame, [dict of str -> sequence], or SkyPattern) – If str, a file path to a csv file. If dict or DataFrame, column names map to their values. Columns must contain ‘time_offset, ‘az_coord’, and ‘alt_coord’. If ‘lst’ is included as a column, certain observation parameters are not required (see options). Otherwise, data is a SkyPattern object.
units ([dict of str -> str or Unit] or None; default None) – If data is not SkyPattern, this mapping column in data with their units. All columns do not need to be mapped. If not provided, all angle-like units are assumed to be in degrees (except for hour angle and lst which are in hourangle) and all time-like units are assumed to be in seconds.
instrument (Instrument or None, default None) – An Instrument object.
data_loc (str or two-tuple; default 'boresight') –

Location relative to the center of the instrument where observation parameters are applied:

1. ‘boresight’ for boresight of the telescope

2. string indicating a module name in the instrument e.g. ‘SFH’ or one of the default slots in the instrument e.g. ‘c’, ‘i1’

3. tuple of (distance, theta) indicating module’s offset from the center of the instrument; default unit deg
obs_param (str) – File path to json containing all required obervation parameters (see **kwargs).

Keyword Arguments

start_ra (float/Quantity/str; default unit deg) – Starting right acension of telescope / right acension offset for sky.
start_dec (float/Quantity/str; default unit deg) – Declination offset for sky_pattern.
lat (float/Quantity/str; default unit deg, default FYST_LOC.lat) – Latitude of observation.
start_datetime (str or datetime; default timezone UTC) – Starting date and time of observation.
start_hrang (float/Quantity/str; default unit hourangle) – Starting hour angle of source.
start_lst (float/Quantity/str; default unit hourangle) – Starting local sidereal time.
start_elev (float/Quantity/str; default unit deg) – Starting elevation of source, must be used with moving_up.
moving_up (bool, default True) – Whether observation is moving towards the meridian or away, must be used with start_elev.

Example

>>> sky_pattern = SkyPattern(sky_pattern.csv)
>>> telescope_pattern1 = TelescopePattern(sky_pattern, data_loc='i1', start_ra='5 hourangle', start_dec='-60 deg', start_elev=30)

get_sky_pattern() → scanning.coordinates.SkyPattern[source]

Returns: A SkyPattern object for the boresight.
Return type: SkyPattern

save_data(path_or_buf=None, columns='default')[source]

Save kinematics data of the boresight.

Parameters

path_or_buf (str, file handle or None; default None) – File path or object, if None is provided the result is returned as a dictionary.
columns (sequence, str or [dict of str -> str/Unit/None]; default 'default') – Columns to write. If dict, map column names to their desired unit and use None if you would like to use the standard. ‘default’ for [‘time_offset’, ‘lst’, ‘az_coord’, ‘alt_coord’, ‘az_vel’, ‘alt_vel’]. ‘all’ for [‘time_offset’, ‘az_coord’, ‘alt_coord’, ‘az_vel’, ‘alt_vel’, ‘vel’, ‘az_acc’, ‘alt_acc’, ‘acc’, ‘az_jerk’, ‘alt_jerk’, ‘jerk’, ‘lst’, ‘hour_angle’, ‘para_angle’, ‘rot_angle’, ‘ra_coord’, ‘dec_coord’].

Returns

If path_or_buf is None, returns the data as a dictionary mapping column name to values. Otherwise returns None.

Return type

None or [dict of str -> array]

Examples

>>> telescope_pattern.save_data('file.csv', columns={'time_offset': 'sec', 'alt_coord': 'arcsec', 'az_coord': None})

save_param(param_json=None)[source]

Save observation parameters.

Parameters: path_or_buf (str, file handle, or None; default None) – File path or object, if None is provided the result is returned as a dictionary.
Returns: If path_or_buf is None, returns the resulting json format as a dictionary. Otherwise returns None.
Return type: None or dict

view_module(module, includes_instr_offset=False)[source]

Get a TelescopePattern object representing the AZ/EL coordinates of the provided module.

Parameters

module (str or two-tuple) –

1. string indicating a module name in the instrument e.g. ‘SFH’

2. string indicating one of the default slots in the instrument e.g. ‘c’, ‘i1’

3. tuple of (distance, theta) indicating module’s offset from the center of the instrument, default unit deg
includes_instr_offset (bool, default False) – if “module” parameter is a tuple of (distance, theta), this includes the instrument offset

Returns

A TelescopePattern object where the “boresight” is the path of the provided module.

Return type

TelescopePattern

property acc

Total acceleration.

Type: Quantity array

property alt_acc

Elevation acceleration.

Type: Quantity array

property alt_coord

Elevation coordinates.

Type: Quantity array

property alt_jerk

Elevation jerk.

Type: Quantity array

property alt_vel

Elevation velocity.

Type: Quantity array

property az_acc

Azimuth acceleration.

Type: Quantity array

property az_coord

Azimuth coordinates (in terms of East of North).

Type: Quantity array

property az_jerk

Azimuth jerk.

Type: Quantity array

property az_vel

Azimuth velocity.

Type: Quantity array

property dec_coord

Declination.

Type: Quantity array

property hour_angle

Hour angle.

Type: Quantity array

property instrument

Insturment object.

Type: Insturment

property jerk

Total jerk.

Type: Quantity array

property lst

Local sidereal time.

Type: Quantity array

property para_angle

Parallactic angle.

Type: Quantity array

property param

Parameters inputted by user.

Type: dict

property ra_coord

Right ascension.

Type: Quantity array

property rot_angle

Field rotation (elevation + parallactic angle).

Type: Quantity array

property sample_interval

Time between samples.

Type: Quantity

property scan_duration

Total scan duration.

Type: Quantity

property time_offset

Time offsets.

Type: Quantity array

property vel

Total velocity.

Type: Quantity array

Simulation

class scanning.optimization.Simulation(telescope_pattern, instrument, module_identifier, sim_param=None, **kwargs)[source]

__init__(telescope_pattern, instrument, module_identifier, sim_param=None, **kwargs) → None[source]

Creating a Simulation object works by passing a TelescopePattern object, which stores the AZ/EL coordinates of the telescope boresight. By passing an Instrument object and the name of one of its modules, we use the detector element positions of that camera module and use the coordinates of the scan pattern that that camera module would make.

Use **kwargs to specify conditions. Note that if multiple detector filters are used (pols_on, det_lim, etc.), only detector elements that satisfy all will be used.

Parameters

telescope_pattern (TelescopePattern) – A TelescopePattern object representing the boresight.
instrument (Instrument) – Instrument object to get module from.
module_identifier (str) – Gets the Module and AZ/ALT coordinates from a string indicating a module name in the instrument e.g. ‘SFH’.
sim_param (str) – File path to a json file containing parameters for simulation (see **kwargs).

Keyword Arguments

mem_limit (int; default 640 MB) – Approximate memory limit in megabytes when simulating the scan.
pixel_size (float/Quantity/str; default 10 arcsec, default unit arcsec) – Length of a square pixel in x-y offsets.
max_acc (float/Quantity/str; default None, default unit deg/s^2) – Maximum absolute accleration in x-y offsets. If None, all points are considered valid.
min_acc (float/Quantity/str; default None, default unit deg/s) – Minimum speed in x-y offsets. If None, all points are considered valid.
pols_on (int, int sequence or None; default None FIXME allow other units) – Which polarization geometries (in degrees) of the detector elements to keep on. If None, include all.
rhombi_on (int, int sequence or None; default None) – Which rhombi to keep on. If None, include all rhombi.
wafers_on (int, int sequence or None; default None) – Which wafers to keep on. If None, include all wafers.
det_radius (two-length tuple or None; default None; default unit arcsec) – Take the (min_radius, max_radius) of detector elements to keep. Use None in the tuple for an unspecified limit. If None, include all.
det_lim (two-length sequence of two-length tuples or None; default None; default unit arcsec) – Take the [(x_min, x_max), (y_min, y_max)] range of detector elements to keep. Use None in the tuple for an unspecified limit. If None, include all. FIXME is this with mod_rot? instr_rot? field rotation?
det_list (sequence of int, sequence of two-length tuples, or None; default None) – If a sequence of int, a list of detector numbers to keep on exact detector elements. If a sequence of two-length tuples, a list of (x, y) positions to keep on the detector element closest to each position; default unit arcsec If `None, include all. FIXME is this with mod_rot? instr_rot? field rotation?
pxan_lim (two-length sequence of two-length tuples or None; default None; default unit arcsec) – A recutangular range of x-y pixels within [(xmin, xmax), (ymin, ymax)] to perform analysis. Cannot be used with pxan_list. If both are None, no pixel analysis is performed.
pxan_list (sequence of two-length tuples, or None; default None; default unit arcsec) – A list of pixels such as [(x1, y1), (x2, y2)] to analyze. Each point (x, y) corresponds to a singular pixel that contains this point. Cannot be used with pxan_lim. If both are None, no pixel analysis is performed.

det_histogram(hits='kept', norm_pxan=True, norm_time=False, path=None)[source]

Get a histogram of the number of hits per detector element on a pixel on the sky (specified in pxan_list or pxan_lim).

Parameters

hits (str; default 'kept') – One of ‘kept’, ‘removed’, or ‘total’ hits.
norm_pxan (bool; default True) – Whether to average the hits by dividing the total hits by the number of pixels.
norm_time (bool; default False) – True for hits/px per total scan duration. False for hits/px.
path_or_buf (str, file handle or None; default None) – File path or object, if None is provided the result is returned. The file is saved as a csv.

Returns

If path_or_buf is None, returns the counts for each detector element as well as the corresponding detector number. NaN values mean that detector element has been filtered off. Otherwise returns None.

Return type

None or (float array, int array)

pol_histogram(hits='kept', path=None)[source]: TODO add documentation

sky_histogram(hits='kept', convolve=True, norm_time=False, path_or_buf=None)[source]

Get a 2D histogram of the resultant hitmap.

Parameters

hits (str; default 'kept') – One of ‘kept’, ‘removed’, or ‘total’ hits.
convolve (bool; default True) – Whether to convolve the hitmap.
norm_time (bool; default False) – True for hits/px per total scan duration. False for hits/px.
path_or_buf (str, file handle or None; default None) – File path or object, if None is provided the result is returned. The file is saved as a csv with the header and columns representing the bin edges (in deg).

Returns

If path_or_buf is None, returns a 2D histogram of the hits as well as the bin edges. Otherwise returns None.

Return type

None or (2d float array, Quantity array)

time_histogram(hits='kept', norm_pxan=True, norm_time=False, path=None)[source]

Get a histogram of the number of hits at each time step on a pixel on the sky (specified in pxan_list or pxan_lim).

Parameters

hits (str; default 'kept') – One of ‘kept’, ‘removed’, or ‘total’ hits.
norm_pxan (bool; default True) – Whether to average the hits by dividing the total hits by the number of pixels.
norm_time (bool; default False) – True for hits/px per total scan duration. False for hits/px.
path_or_buf (str, file handle or None; default None) – File path or object, if None is provided the result is returned. The file is saved as a csv.

Returns

If path_or_buf is None, returns the counts for each time step as well as the corresponding time offset. NaN values mean that time step is out/in the speed/accleration limits. Otherwise returns None.

Return type

None or (float array, int array)

property det_mask

Mask for detector elements that are turned on.

Type: bool array

property field_rotation

Field rotation.

Type: Quantity array

property module

Module object.

Type: Module

property sky_pattern

Associated SkyPattern object.

Type: SkyPattern

property validity_mask

Mask for samples that are within the acceleration/speed limits.

Type: bool array

Observation

class scanning.observation.Observation(dec, hrang_range=None, datetime_range=None, ra=None, freq=None, lat=<Latitude -22.98563889 deg>)[source]

__init__(dec, hrang_range=None, datetime_range=None, ra=None, freq=None, lat=<Latitude -22.98563889 deg>) → None[source]

Initialize an observation of a particular source(s) for a particular time range.

Parameters

dec (angle-like or iterable, default unit deg) – Declination(s) of your source.
hrang_range ((angle-like, angle-like) or None, default unit hourangle) – (start, end) range of hour angles to consider. If both hrang_range and datetime_range is None, this is by default the full -12 to 12 range. Note that start must be less than end. Cannot be larger than -12 to 12 range. Cannot be used with datetime_range.
datetime_range ((str or datetime-like, str or datetime-like) or None, default None.) – (start, end) range of datetimes to consider. Cannot be used with hrang_range. Must include ra.
ra (angle-like or iterable, default unit deg) – Right ascensions(s) of your source. Required if datetime_range is passed.
freq (time-like, default unit seconds) – The timestep between points. By default, the will be enough so that there are 1500 points.
lat (angle-like, default unit deg, default FYST_LOC.lat) – Latitude of observation.

filter(min_elev=30, max_elev=75, min_rot_rate=0)[source]

Filter the time ranges when

Parameters

min_elev (angle-like, default unit deg, default 30 deg) – Minimum elevation to consider.
max_elev (angle-like, default unit deg, default 75 deg) – Maximum elevation to consider.
min_rot_rate (angular velocity-like, default unit deg, default 0 deg/s) – Minimum absolute field rotation rate to consider.

Returns

In the format of {index of source : list of tuples}. Each tuple is a range of valid times, in datetime.datetime if datetime_range was provided, otherwise in hour angles.

Return type

dict