gemini_instruments.gemini package

class gemini_instruments.gemini.AstroDataGemini(provider)[source]

Bases: astrodata.fits.AstroDataFits

airmass()[source]

Returns the airmass of the observation.

Returns:Airmass value.
Return type:float
amp_read_area(pretty=False)[source]

Returns the readout area of each amplifier, as a 0-based tuple or 1-based string

Returns:the amp readout areas
Return type:list/(tuple or string)
ao_seeing()[source]

Returns an estimate of the natural seeing as calculated from the adaptive optics systems.

Returns:AO estimate of the natural seeing
Return type:float
array_name()[source]

Returns the name of each array

Returns:the array names
Return type:list of str/str
array_section(pretty=False)[source]

Returns the section covered by the array(s) relative to the detector frame. For example, this can be the position of multiple amps read within a CCD. If pretty is False, a tuple of 0-based coordinates is returned with format (x1, x2, y1, y2). If pretty is True, a keyword value is returned without parsing as a string. In this format, the coordinates are generally 1-based.

One tuple or string is return per extension/array, in a list. If the method is called on a single slice, the section is returned as a tuple or a string.

Parameters:pretty (bool) – If True, return the formatted string found in the header.
Returns:
  • tuple of integers or list of tuples – Position of extension(s) using Python slice values
  • str/list of str – Position of extension(s) using an IRAF section format (1-based)
azimuth()[source]

Returns the azimuth of the telescope, in degrees

Returns:azimuth
Return type:float
calibration_key()[source]

Returns an object to be used as a key in the Calibrations dict. Multiple ADs can share a key but there can be only one of each type of calibration for each key. data_label() is the default. “_stack” is removed to avoid making a new request for a stacked frame, which will need the same calibration as the original.

Returns:identifier
Return type:string
camera(stripID=False, pretty=False)[source]

Returns the name of the camera. The component ID can be removed with either ‘stripID’ or ‘pretty’ set to True.

Parameters:
  • stripID (bool) – If True, removes the component ID and returns only the name of the camera.
  • pretty (bool) – Same as for stripID. Pretty here does not do anything more.
Returns:

The name of the camera with or without the component ID.

Return type:

str

cass_rotator_pa()[source]

Returns the position angle of the Cassegrain rotator, in degrees.

Returns:Position angle of the Cassegrain rotator.
Return type:float
central_wavelength(asMicrometers=False, asNanometers=False, asAngstroms=False)[source]

Returns the central wavelength in meters or the specified units

Parameters:
  • asMicrometers (bool) – If True, return the wavelength in microns
  • asNanometers (bool) – If True, return the wavelength in nanometers
  • asAngstroms (bool) – If True, return the wavelength in Angstroms
Returns:

The central wavelength setting

Return type:

float

coadds()[source]

Returns the number of co-adds used for the observation.

Returns:Number of co-adds.
Return type:int
data_label()[source]

Returns the data label of an observation.

Returns:the observation’s data label
Return type:str
data_section(pretty=False)[source]

Returns the rectangular section that includes the pixels that would be exposed to light. If pretty is False, a tuple of 0-based coordinates is returned with format (x1, x2, y1, y2). If pretty is True, a keyword value is returned without parsing as a string. In this format, the coordinates are generally 1-based.

One tuple or string is return per extension/array, in a list. If the method is called on a single slice, the section is returned as a tuple or a string.

Parameters:pretty (bool) – If True, return the formatted string found in the header.
Returns:
  • tuple of integers or list of tuples – Location of the pixels exposed to light using Python slice values.
  • string or list of strings – Location of the pixels exposed to light using an IRAF section format (1-based).
dec()[source]

Returns the Declination of the center of the field, in degrees.

Returns:declination in degrees
Return type:float
decker(stripID=False, pretty=False)[source]

Returns the name of the decker. The component ID can be removed with either ‘stripID’ or ‘pretty’ set to True.

Parameters:
  • stripID (bool) – If True, removes the component ID and returns only the name of the decker.
  • pretty (bool) – Same as for stripID. Pretty here does not do anything more.
Returns:

The name of the decker with or without the component ID.

Return type:

str

detector_name(pretty=False)[source]

Returns the name of the detector

Returns:the detector name
Return type:str
detector_roi_setting()[source]

Returns the ROI setting. Most instruments don’t allow this to be changed, so at the Gemini level it just returns ‘Fixed’

Returns:Name of the ROI setting used, ie, “Fixed”
Return type:str
detector_rois_requested()[source]

Returns the ROIs requested. Since most instruments don’t have selectable ROIs, it returns None at the Gemini level

Returns:None
Return type:NoneType
detector_section(pretty=False)[source]

Returns the section covered by the detector relative to the whole mosaic of detectors. If pretty is False, a tuple of 0-based coordinates is returned with format (x1, x2, y1, y2). If pretty is True, a keyword value is returned without parsing as a string. In this format, the coordinates are generally 1-based.

One tuple or string is return per extension/array, in a list. If the method is called on a single slice, the section is returned as a tuple or a string.

Parameters:pretty (bool) – If True, return the formatted string found in the header.
Returns:
  • tuple of integers or list of tuples – Position of the detector using Python slice values.
  • string or list of strings – Position of the detector using an IRAF section format (1-based).
detector_x_bin()[source]

Returns the detector binning in the x-direction

Returns:The detector binning
Return type:int
detector_x_offset()[source]

Returns the offset from the reference position in pixels along the positive x-direction of the detector

Returns:The offset in pixels
Return type:float
detector_y_bin()[source]

Returns the detector binning in the y-direction

Returns:The detector binning
Return type:int
detector_y_offset()[source]

Returns the offset from the reference position in pixels along the positive y-direction of the detector

Returns:The offset in pixels
Return type:float
disperser(stripID=False, pretty=False)[source]

Returns the name of the disperser. The “disperser” is a combination of all the dispersing elements along the light path.

The component ID can be removed with either ‘stripID’ or ‘pretty’ set to True.

Parameters:
  • stripID (bool) – If True, removes the component ID and returns only the name of the disperser.
  • pretty (bool) – Same as for stripID. Pretty here does not do anything more.
Returns:

The name of the disperser with or without the component ID.

Return type:

str

dispersion(asMicrometers=False, asNanometers=False, asAngstroms=False)[source]

Returns the dispersion in meters per pixel as a list (one value per extension) or a float if used on a single-extension slice. It is possible to control the units of wavelength using the input arguments.

Parameters:
  • asMicrometers (bool) – If True, return the wavelength in microns
  • asNanometers (bool) – If True, return the wavelength in nanometers
  • asAngstroms (bool) – If True, return the wavelength in Angstroms
Returns:

The dispersion(s)

Return type:

list/float

dispersion_axis()[source]

Returns the axis along which the light is dispersed.

Returns:Dispersion axis.
Return type:int
effective_wavelength(output_units=None)[source]

Returns the wavelength representing the bandpass or the spectrum. For imaging data this normally is the wavelength at the center of the bandpass as defined by the filter used. For spectra, this is the central wavelength. The returned value is in meters.

This descriptor makes uses of a lookup table to associate filters with their effective_wavelength.

Returns:Wavelength representing the bandpass or the spectrum coverage.
Return type:float
elevation()[source]

Returns the elevation of the telescope, in degrees

Returns:elevation
Return type:float
exposure_time()[source]

Returns the exposure time in seconds.

Returns:Exposure time.
Return type:float
filter_name(stripID=False, pretty=False)[source]

Returns the name of the filter(s) used. The component ID can be removed with either ‘stripID’ or ‘pretty’. If a combination of filters is used, the filter names will be join into a unique string with ‘&’ as separator. If ‘pretty’ is True, filter positions such as ‘Open’, ‘Dark’, ‘blank’, and others are removed leaving only the relevant filters in the string.

Parameters:
  • stripID (bool) – If True, removes the component ID and returns only the name of the filter.
  • pretty (bool) – Same as for stripID. Pretty here does not do anything more.
Returns:

The name of the filter combination with or without the component ID.

Return type:

str

focal_plane_mask(stripID=False, pretty=False)[source]

Returns the name of the focal plane mask. The component ID can be removed with either ‘stripID’ or ‘pretty’ set to True.

Parameters:
  • stripID (bool) – If True, removes the component ID and returns only the name of the focal plane mask.
  • pretty (bool) – Same as for stripID. Pretty here does not do anything more.
Returns:

The name of the focal plane mask with or without the component ID.

Return type:

str

gain()[source]

Returns the gain (electrons/ADU) for each extension

Returns:Gains used for the observation
Return type:list of floats/float
gain_setting()[source]

Returns the gain setting for this observation (e.g., ‘high’, ‘low’)

Returns:the gain setting
Return type:str
gcal_lamp()[source]

Returns the name of the GCAL lamp being used, or “Off” if no lamp is in used. This applies to flats and arc observations when a lamp is used. For other types observation, None is returned.

Returns:Name of the GCAL lamp being used, or “Off” if not in use.
Return type:str
group_id()[source]

Returns a string representing a group of data that are compatible with each other. This is used when stacking, for example. Each instrument and mode of observation will have its own rules.

At the Gemini class level, the default is to group by the Gemini observation ID.

Returns:A group ID for compatible data.
Return type:str
instrument(generic=False)[source]

Returns the name of the instrument making the observation

Parameters:generic (boolean) – If set, don’t specify the specific instrument if there are clones (but that is handled by the instrument-level descriptors)
Returns:instrument name
Return type:str
is_ao()[source]

Tells whether or not the data was taken with adaptive optics.

Returns:True if the data is AO, False otherwise.
Return type:bool
is_coadds_summed()[source]

Tells whether or not the co-adds have been summed. If not, they have been averaged.

At the Gemini level, this descriptor is hardcoded to True as it is the default at the observatory.

Returns:True if the data has been summed. False if it has been averaged.
Return type:bool
is_in_adu()[source]

Tells whether the data are in ADU (likely to be superseded by use of NDData’s unit attribute)

Returns:True if the data are in ADU
Return type:bool
local_time()[source]

Returns the local time stored at the time of the observation.

Returns:Local time of the observation.
Return type:datetime.datetime.time()
lyot_stop(stripID=False, pretty=False)[source]

Returns the Lyot stop used for the observation

Parameters:
  • stripID (bool) – If True, removes the component ID.
  • pretty (bool) – Same as for stripID.
Returns:

Lyot stop used for the observation

Return type:

str

mdf_row_id()[source]

Returns row ID from the MDF (Mask Definition File) table associated with the spectrum. Applies to “cut” MOS or X-dispersed data.

Returns:Row of the MDF associated with the extension.
Return type:int
nominal_atmospheric_extinction()[source]

Returns the nominal atmospheric extinction at observation airmass and bandpass.

Returns:Nominal atmospheric extinction from model.
Return type:float
nominal_photometric_zeropoint()[source]

Returns the nominal photometric zeropoint (i.e., magnitude corresponding to 1 pixel count) for each extension

Returns:Photometric zeropoint
Return type:float/list of floats
non_linear_level()[source]

Returns the level at which the data become non-linear, in ADU. This is expected to be overridden by the individual instruments, so at the Gemini level it returns the values of the NONLINEA keywords (or None)

Returns:non-linearity level level in ADU
Return type:int/list
observation_class()[source]

Returns the class of an observation, e.g., ‘science’, ‘acq’, ‘dayCal’.

Returns:the observation class
Return type:str
observation_epoch()[source]

Returns the observation’s epoch.

Returns:the observation’s epoch
Return type:str
observation_id()[source]

Returns the ID of an observation.

Returns:the observation ID
Return type:str
observation_type()[source]

Returns the type of an observation, e.g., ‘OBJECT’, ‘FLAT’, ‘ARC’.

Returns:the observation type
Return type:str
overscan_section(pretty=False)[source]

Returns the section covered by the overscan regions relative to the detector frame. If pretty is False, a tuple of 0-based coordinates is returned with format (x1, x2, y1, y2). If pretty is True, a keyword value is returned without parsing as a string. In this format, the coordinates are generally 1-based.

One tuple or string is return per extension/array. If more than one array, the tuples/strings are return in a list. Otherwise, the section is returned as a tuple or a string.

Parameters:pretty (bool) – If True, return the formatted string found in the header.
Returns:
  • tuple of integers or list of tuples – Position of extension(s) using Python slice values
  • str/list of str – Position of extension(s) using an IRAF section format (1-based)
pixel_scale()[source]

Returns the image scale in arcseconds per pixel, as an average over the extensions

Returns:the pixel scale
Return type:float
program_id()[source]

Returns the ID of the program the observation was taken for

Returns:the program ID
Return type:str
pupil_mask(stripID=False, pretty=False)[source]

Returns the name of the focal plane mask. The component ID can be removed with either ‘stripID’ or ‘pretty’ set to True.

Parameters:
  • stripID (bool) – If True, removes the component ID and returns only the name of the focal plane mask.
  • pretty (bool) – Same as for stripID. Pretty here does not do anything more.
Returns:

The name of the focal plane mask with or without the component ID.

Return type:

str

qa_state()[source]

Returns the Gemini quality assessment flags.

Returns:Gemini quality assessment flags.
Return type:str
ra()[source]

Returns the Right Ascension of the center of the field, in degrees.

Returns:right ascension in degrees
Return type:float
raw_bg()[source]

Returns the BG percentile band of the observation. BG refers to the sky/background brightness.

Returns:BG percentile band of the observation.
Return type:str
raw_cc()[source]

Returns the CC percentile band of the observation. CC refers to the cloud coverage.

Returns:CC percentile band of the observation.
Return type:str
raw_iq()[source]

Returns the IQ percentile band of the observation. IQ refers to the image quality or seeing.

Returns:IQ percentile band of the observation.
Return type:str
raw_wv()[source]

Returns the WV percentile band of the observation. WV refers to the water vapor.

Returns:WV percentile band of the observation.
Return type:str
read_mode()[source]

Returns the readout mode used for the observation

Returns:the read mode used
Return type:str
read_noise()[source]

Returns the read noise in electrons for each extension. A list is returned unless called on a single-extension slice, when a float

Returns:the read noise
Return type:float/list of floats
read_speed_setting()[source]

Returns the read speed setting for the observation

Returns:the read speed setting
Return type:str
requested_bg()[source]

Returns the BG percentile band requested by the PI. BG refers to the sky/background brightness.

Returns:BG percentile band requested by the PI.
Return type:str
requested_cc()[source]

Returns the CC percentile band requested by the PI. CC refers to the cloud coverage.

Returns:CC percentile band requested by the PI.
Return type:str
requested_iq()[source]

Returns the IQ percentile band requested by the PI. IQ refers to the image quality or seeing.

Returns:IQ percentile band requested by the PI.
Return type:str
requested_wv()[source]

Returns the WV percentile band requested by the PI. WV refers to the water vapor.

Returns:WV percentile band requested by the PI.
Return type:str
saturation_level()[source]

Returns the saturation level of the data, in ADU. This is expected to be overridden by the individual instruments, so at the Gemini level it returns the values of the SATLEVEL keywords (or None)

Returns:saturation level in ADU
Return type:list/float
slit()[source]

Returns the name of the entrance slit used for the observation

Returns:the slit name
Return type:str
target_dec(offset=False, pm=True, icrs=False)[source]

Returns the Declination of the target in degrees. Optionally, the telescope offsets can be applied. The proper motion can also be applied if requested. Finally, the RA can be converted to ICRS coordinates.

Parameters:
  • offset (bool) – If True, applies the telescope offsets.
  • pm (bool) – If True, applies proper motion parameters.
  • icrs (bool) – If True, convert the Declination to the ICRS coordinate system.
Returns:

Declination of the target in degrees.

Return type:

float

target_ra(offset=False, pm=True, icrs=False)[source]

Returns the Right Ascension of the target in degrees. Optionally, the telescope offsets can be applied. The proper motion can also be applied if requested. Finally, the RA can be converted to ICRS coordinates.

Parameters:
  • offset (bool) – If True, applies the telescope offsets.
  • pm (bool) – If True, applies proper motion parameters.
  • icrs (bool) – If True, convert the RA to the ICRS coordinate system.
Returns:

Right Ascension of the target in degrees.

Return type:

float

telescope_x_offset()[source]

Returns the telescope offset along the telescope x-axis, in arcseconds.

Returns:the telescope offset along the telescope x-axis (arcseconds)
Return type:float
telescope_y_offset()[source]

Returns the telescope offset along the telescope y-axis, in arcseconds.

Returns:the telescope offset along the telescope y-axis (arcseconds)
Return type:float
ut_date()[source]

Returns the UT date of the observation as a datetime object.

Returns:UT date.
Return type:datetime.datetime
ut_datetime(strict=False, dateonly=False, timeonly=False)[source]

Returns the UT date and/or time of the observation as a datetime or date or time object.

Parameters:
  • strict (bool) – if True, only information in the header can be used
  • dateonly (bool) – if True, return a date object with just the date
  • timeonly (bool) – if True, return a time object with just the time
Returns:

UT date and/or time

Return type:

datetime.datetime / datetime.date / datetime.time

ut_time()[source]

Returns the UT time of the observation as a datetime object.

Returns:UT time.
Return type:datetime.datetime
wavefront_sensor()[source]

Returns the name of the wavefront sensor used for the observation. If more than one is being used, the names will be joined with ‘&’.

Returns:Name of the wavefront sensor.
Return type:str
wavelength_band()[source]

Returns the name of the bandpass of the observation. This is just to broadly know what type of data one is working with, eg. K band, H band, B band, etc.

Returns:Name of the bandpass.
Return type:str
wcs_dec()[source]

Returns the Declination of the center of the field based on the WCS rather than the DEC header keyword.

Returns:declination in degrees
Return type:float
wcs_ra()[source]

Returns the Right Ascension of the center of the field based on the WCS rather than the RA header keyword.

Returns:right ascension in degrees
Return type:float
well_depth_setting()[source]

Returns a string describing the well-depth setting of the instrument

Returns:the well-depth setting
Return type:str
gemini_instruments.gemini.addInstrumentFilterWavelengths(instrument, wl)[source]

Submodules

gemini_instruments.gemini.adclass module

class gemini_instruments.gemini.adclass.AstroDataGemini(provider)[source]

Bases: astrodata.fits.AstroDataFits

airmass()[source]

Returns the airmass of the observation.

Returns:Airmass value.
Return type:float
amp_read_area(pretty=False)[source]

Returns the readout area of each amplifier, as a 0-based tuple or 1-based string

Returns:the amp readout areas
Return type:list/(tuple or string)
ao_seeing()[source]

Returns an estimate of the natural seeing as calculated from the adaptive optics systems.

Returns:AO estimate of the natural seeing
Return type:float
array_name()[source]

Returns the name of each array

Returns:the array names
Return type:list of str/str
array_section(pretty=False)[source]

Returns the section covered by the array(s) relative to the detector frame. For example, this can be the position of multiple amps read within a CCD. If pretty is False, a tuple of 0-based coordinates is returned with format (x1, x2, y1, y2). If pretty is True, a keyword value is returned without parsing as a string. In this format, the coordinates are generally 1-based.

One tuple or string is return per extension/array, in a list. If the method is called on a single slice, the section is returned as a tuple or a string.

Parameters:pretty (bool) – If True, return the formatted string found in the header.
Returns:
  • tuple of integers or list of tuples – Position of extension(s) using Python slice values
  • str/list of str – Position of extension(s) using an IRAF section format (1-based)
azimuth()[source]

Returns the azimuth of the telescope, in degrees

Returns:azimuth
Return type:float
calibration_key()[source]

Returns an object to be used as a key in the Calibrations dict. Multiple ADs can share a key but there can be only one of each type of calibration for each key. data_label() is the default. “_stack” is removed to avoid making a new request for a stacked frame, which will need the same calibration as the original.

Returns:identifier
Return type:string
camera(stripID=False, pretty=False)[source]

Returns the name of the camera. The component ID can be removed with either ‘stripID’ or ‘pretty’ set to True.

Parameters:
  • stripID (bool) – If True, removes the component ID and returns only the name of the camera.
  • pretty (bool) – Same as for stripID. Pretty here does not do anything more.
Returns:

The name of the camera with or without the component ID.

Return type:

str

cass_rotator_pa()[source]

Returns the position angle of the Cassegrain rotator, in degrees.

Returns:Position angle of the Cassegrain rotator.
Return type:float
central_wavelength(asMicrometers=False, asNanometers=False, asAngstroms=False)[source]

Returns the central wavelength in meters or the specified units

Parameters:
  • asMicrometers (bool) – If True, return the wavelength in microns
  • asNanometers (bool) – If True, return the wavelength in nanometers
  • asAngstroms (bool) – If True, return the wavelength in Angstroms
Returns:

The central wavelength setting

Return type:

float

coadds()[source]

Returns the number of co-adds used for the observation.

Returns:Number of co-adds.
Return type:int
data_label()[source]

Returns the data label of an observation.

Returns:the observation’s data label
Return type:str
data_section(pretty=False)[source]

Returns the rectangular section that includes the pixels that would be exposed to light. If pretty is False, a tuple of 0-based coordinates is returned with format (x1, x2, y1, y2). If pretty is True, a keyword value is returned without parsing as a string. In this format, the coordinates are generally 1-based.

One tuple or string is return per extension/array, in a list. If the method is called on a single slice, the section is returned as a tuple or a string.

Parameters:pretty (bool) – If True, return the formatted string found in the header.
Returns:
  • tuple of integers or list of tuples – Location of the pixels exposed to light using Python slice values.
  • string or list of strings – Location of the pixels exposed to light using an IRAF section format (1-based).
dec()[source]

Returns the Declination of the center of the field, in degrees.

Returns:declination in degrees
Return type:float
decker(stripID=False, pretty=False)[source]

Returns the name of the decker. The component ID can be removed with either ‘stripID’ or ‘pretty’ set to True.

Parameters:
  • stripID (bool) – If True, removes the component ID and returns only the name of the decker.
  • pretty (bool) – Same as for stripID. Pretty here does not do anything more.
Returns:

The name of the decker with or without the component ID.

Return type:

str

detector_name(pretty=False)[source]

Returns the name of the detector

Returns:the detector name
Return type:str
detector_roi_setting()[source]

Returns the ROI setting. Most instruments don’t allow this to be changed, so at the Gemini level it just returns ‘Fixed’

Returns:Name of the ROI setting used, ie, “Fixed”
Return type:str
detector_rois_requested()[source]

Returns the ROIs requested. Since most instruments don’t have selectable ROIs, it returns None at the Gemini level

Returns:None
Return type:NoneType
detector_section(pretty=False)[source]

Returns the section covered by the detector relative to the whole mosaic of detectors. If pretty is False, a tuple of 0-based coordinates is returned with format (x1, x2, y1, y2). If pretty is True, a keyword value is returned without parsing as a string. In this format, the coordinates are generally 1-based.

One tuple or string is return per extension/array, in a list. If the method is called on a single slice, the section is returned as a tuple or a string.

Parameters:pretty (bool) – If True, return the formatted string found in the header.
Returns:
  • tuple of integers or list of tuples – Position of the detector using Python slice values.
  • string or list of strings – Position of the detector using an IRAF section format (1-based).
detector_x_bin()[source]

Returns the detector binning in the x-direction

Returns:The detector binning
Return type:int
detector_x_offset()[source]

Returns the offset from the reference position in pixels along the positive x-direction of the detector

Returns:The offset in pixels
Return type:float
detector_y_bin()[source]

Returns the detector binning in the y-direction

Returns:The detector binning
Return type:int
detector_y_offset()[source]

Returns the offset from the reference position in pixels along the positive y-direction of the detector

Returns:The offset in pixels
Return type:float
disperser(stripID=False, pretty=False)[source]

Returns the name of the disperser. The “disperser” is a combination of all the dispersing elements along the light path.

The component ID can be removed with either ‘stripID’ or ‘pretty’ set to True.

Parameters:
  • stripID (bool) – If True, removes the component ID and returns only the name of the disperser.
  • pretty (bool) – Same as for stripID. Pretty here does not do anything more.
Returns:

The name of the disperser with or without the component ID.

Return type:

str

dispersion(asMicrometers=False, asNanometers=False, asAngstroms=False)[source]

Returns the dispersion in meters per pixel as a list (one value per extension) or a float if used on a single-extension slice. It is possible to control the units of wavelength using the input arguments.

Parameters:
  • asMicrometers (bool) – If True, return the wavelength in microns
  • asNanometers (bool) – If True, return the wavelength in nanometers
  • asAngstroms (bool) – If True, return the wavelength in Angstroms
Returns:

The dispersion(s)

Return type:

list/float

dispersion_axis()[source]

Returns the axis along which the light is dispersed.

Returns:Dispersion axis.
Return type:int
effective_wavelength(output_units=None)[source]

Returns the wavelength representing the bandpass or the spectrum. For imaging data this normally is the wavelength at the center of the bandpass as defined by the filter used. For spectra, this is the central wavelength. The returned value is in meters.

This descriptor makes uses of a lookup table to associate filters with their effective_wavelength.

Returns:Wavelength representing the bandpass or the spectrum coverage.
Return type:float
elevation()[source]

Returns the elevation of the telescope, in degrees

Returns:elevation
Return type:float
exposure_time()[source]

Returns the exposure time in seconds.

Returns:Exposure time.
Return type:float
filter_name(stripID=False, pretty=False)[source]

Returns the name of the filter(s) used. The component ID can be removed with either ‘stripID’ or ‘pretty’. If a combination of filters is used, the filter names will be join into a unique string with ‘&’ as separator. If ‘pretty’ is True, filter positions such as ‘Open’, ‘Dark’, ‘blank’, and others are removed leaving only the relevant filters in the string.

Parameters:
  • stripID (bool) – If True, removes the component ID and returns only the name of the filter.
  • pretty (bool) – Same as for stripID. Pretty here does not do anything more.
Returns:

The name of the filter combination with or without the component ID.

Return type:

str

focal_plane_mask(stripID=False, pretty=False)[source]

Returns the name of the focal plane mask. The component ID can be removed with either ‘stripID’ or ‘pretty’ set to True.

Parameters:
  • stripID (bool) – If True, removes the component ID and returns only the name of the focal plane mask.
  • pretty (bool) – Same as for stripID. Pretty here does not do anything more.
Returns:

The name of the focal plane mask with or without the component ID.

Return type:

str

gain()[source]

Returns the gain (electrons/ADU) for each extension

Returns:Gains used for the observation
Return type:list of floats/float
gain_setting()[source]

Returns the gain setting for this observation (e.g., ‘high’, ‘low’)

Returns:the gain setting
Return type:str
gcal_lamp()[source]

Returns the name of the GCAL lamp being used, or “Off” if no lamp is in used. This applies to flats and arc observations when a lamp is used. For other types observation, None is returned.

Returns:Name of the GCAL lamp being used, or “Off” if not in use.
Return type:str
group_id()[source]

Returns a string representing a group of data that are compatible with each other. This is used when stacking, for example. Each instrument and mode of observation will have its own rules.

At the Gemini class level, the default is to group by the Gemini observation ID.

Returns:A group ID for compatible data.
Return type:str
instrument(generic=False)[source]

Returns the name of the instrument making the observation

Parameters:generic (boolean) – If set, don’t specify the specific instrument if there are clones (but that is handled by the instrument-level descriptors)
Returns:instrument name
Return type:str
is_ao()[source]

Tells whether or not the data was taken with adaptive optics.

Returns:True if the data is AO, False otherwise.
Return type:bool
is_coadds_summed()[source]

Tells whether or not the co-adds have been summed. If not, they have been averaged.

At the Gemini level, this descriptor is hardcoded to True as it is the default at the observatory.

Returns:True if the data has been summed. False if it has been averaged.
Return type:bool
is_in_adu()[source]

Tells whether the data are in ADU (likely to be superseded by use of NDData’s unit attribute)

Returns:True if the data are in ADU
Return type:bool
local_time()[source]

Returns the local time stored at the time of the observation.

Returns:Local time of the observation.
Return type:datetime.datetime.time()
lyot_stop(stripID=False, pretty=False)[source]

Returns the Lyot stop used for the observation

Parameters:
  • stripID (bool) – If True, removes the component ID.
  • pretty (bool) – Same as for stripID.
Returns:

Lyot stop used for the observation

Return type:

str

mdf_row_id()[source]

Returns row ID from the MDF (Mask Definition File) table associated with the spectrum. Applies to “cut” MOS or X-dispersed data.

Returns:Row of the MDF associated with the extension.
Return type:int
nominal_atmospheric_extinction()[source]

Returns the nominal atmospheric extinction at observation airmass and bandpass.

Returns:Nominal atmospheric extinction from model.
Return type:float
nominal_photometric_zeropoint()[source]

Returns the nominal photometric zeropoint (i.e., magnitude corresponding to 1 pixel count) for each extension

Returns:Photometric zeropoint
Return type:float/list of floats
non_linear_level()[source]

Returns the level at which the data become non-linear, in ADU. This is expected to be overridden by the individual instruments, so at the Gemini level it returns the values of the NONLINEA keywords (or None)

Returns:non-linearity level level in ADU
Return type:int/list
observation_class()[source]

Returns the class of an observation, e.g., ‘science’, ‘acq’, ‘dayCal’.

Returns:the observation class
Return type:str
observation_epoch()[source]

Returns the observation’s epoch.

Returns:the observation’s epoch
Return type:str
observation_id()[source]

Returns the ID of an observation.

Returns:the observation ID
Return type:str
observation_type()[source]

Returns the type of an observation, e.g., ‘OBJECT’, ‘FLAT’, ‘ARC’.

Returns:the observation type
Return type:str
overscan_section(pretty=False)[source]

Returns the section covered by the overscan regions relative to the detector frame. If pretty is False, a tuple of 0-based coordinates is returned with format (x1, x2, y1, y2). If pretty is True, a keyword value is returned without parsing as a string. In this format, the coordinates are generally 1-based.

One tuple or string is return per extension/array. If more than one array, the tuples/strings are return in a list. Otherwise, the section is returned as a tuple or a string.

Parameters:pretty (bool) – If True, return the formatted string found in the header.
Returns:
  • tuple of integers or list of tuples – Position of extension(s) using Python slice values
  • str/list of str – Position of extension(s) using an IRAF section format (1-based)
pixel_scale()[source]

Returns the image scale in arcseconds per pixel, as an average over the extensions

Returns:the pixel scale
Return type:float
program_id()[source]

Returns the ID of the program the observation was taken for

Returns:the program ID
Return type:str
pupil_mask(stripID=False, pretty=False)[source]

Returns the name of the focal plane mask. The component ID can be removed with either ‘stripID’ or ‘pretty’ set to True.

Parameters:
  • stripID (bool) – If True, removes the component ID and returns only the name of the focal plane mask.
  • pretty (bool) – Same as for stripID. Pretty here does not do anything more.
Returns:

The name of the focal plane mask with or without the component ID.

Return type:

str

qa_state()[source]

Returns the Gemini quality assessment flags.

Returns:Gemini quality assessment flags.
Return type:str
ra()[source]

Returns the Right Ascension of the center of the field, in degrees.

Returns:right ascension in degrees
Return type:float
raw_bg()[source]

Returns the BG percentile band of the observation. BG refers to the sky/background brightness.

Returns:BG percentile band of the observation.
Return type:str
raw_cc()[source]

Returns the CC percentile band of the observation. CC refers to the cloud coverage.

Returns:CC percentile band of the observation.
Return type:str
raw_iq()[source]

Returns the IQ percentile band of the observation. IQ refers to the image quality or seeing.

Returns:IQ percentile band of the observation.
Return type:str
raw_wv()[source]

Returns the WV percentile band of the observation. WV refers to the water vapor.

Returns:WV percentile band of the observation.
Return type:str
read_mode()[source]

Returns the readout mode used for the observation

Returns:the read mode used
Return type:str
read_noise()[source]

Returns the read noise in electrons for each extension. A list is returned unless called on a single-extension slice, when a float

Returns:the read noise
Return type:float/list of floats
read_speed_setting()[source]

Returns the read speed setting for the observation

Returns:the read speed setting
Return type:str
requested_bg()[source]

Returns the BG percentile band requested by the PI. BG refers to the sky/background brightness.

Returns:BG percentile band requested by the PI.
Return type:str
requested_cc()[source]

Returns the CC percentile band requested by the PI. CC refers to the cloud coverage.

Returns:CC percentile band requested by the PI.
Return type:str
requested_iq()[source]

Returns the IQ percentile band requested by the PI. IQ refers to the image quality or seeing.

Returns:IQ percentile band requested by the PI.
Return type:str
requested_wv()[source]

Returns the WV percentile band requested by the PI. WV refers to the water vapor.

Returns:WV percentile band requested by the PI.
Return type:str
saturation_level()[source]

Returns the saturation level of the data, in ADU. This is expected to be overridden by the individual instruments, so at the Gemini level it returns the values of the SATLEVEL keywords (or None)

Returns:saturation level in ADU
Return type:list/float
slit()[source]

Returns the name of the entrance slit used for the observation

Returns:the slit name
Return type:str
target_dec(offset=False, pm=True, icrs=False)[source]

Returns the Declination of the target in degrees. Optionally, the telescope offsets can be applied. The proper motion can also be applied if requested. Finally, the RA can be converted to ICRS coordinates.

Parameters:
  • offset (bool) – If True, applies the telescope offsets.
  • pm (bool) – If True, applies proper motion parameters.
  • icrs (bool) – If True, convert the Declination to the ICRS coordinate system.
Returns:

Declination of the target in degrees.

Return type:

float

target_ra(offset=False, pm=True, icrs=False)[source]

Returns the Right Ascension of the target in degrees. Optionally, the telescope offsets can be applied. The proper motion can also be applied if requested. Finally, the RA can be converted to ICRS coordinates.

Parameters:
  • offset (bool) – If True, applies the telescope offsets.
  • pm (bool) – If True, applies proper motion parameters.
  • icrs (bool) – If True, convert the RA to the ICRS coordinate system.
Returns:

Right Ascension of the target in degrees.

Return type:

float

telescope_x_offset()[source]

Returns the telescope offset along the telescope x-axis, in arcseconds.

Returns:the telescope offset along the telescope x-axis (arcseconds)
Return type:float
telescope_y_offset()[source]

Returns the telescope offset along the telescope y-axis, in arcseconds.

Returns:the telescope offset along the telescope y-axis (arcseconds)
Return type:float
ut_date()[source]

Returns the UT date of the observation as a datetime object.

Returns:UT date.
Return type:datetime.datetime
ut_datetime(strict=False, dateonly=False, timeonly=False)[source]

Returns the UT date and/or time of the observation as a datetime or date or time object.

Parameters:
  • strict (bool) – if True, only information in the header can be used
  • dateonly (bool) – if True, return a date object with just the date
  • timeonly (bool) – if True, return a time object with just the time
Returns:

UT date and/or time

Return type:

datetime.datetime / datetime.date / datetime.time

ut_time()[source]

Returns the UT time of the observation as a datetime object.

Returns:UT time.
Return type:datetime.datetime
wavefront_sensor()[source]

Returns the name of the wavefront sensor used for the observation. If more than one is being used, the names will be joined with ‘&’.

Returns:Name of the wavefront sensor.
Return type:str
wavelength_band()[source]

Returns the name of the bandpass of the observation. This is just to broadly know what type of data one is working with, eg. K band, H band, B band, etc.

Returns:Name of the bandpass.
Return type:str
wcs_dec()[source]

Returns the Declination of the center of the field based on the WCS rather than the DEC header keyword.

Returns:declination in degrees
Return type:float
wcs_ra()[source]

Returns the Right Ascension of the center of the field based on the WCS rather than the RA header keyword.

Returns:right ascension in degrees
Return type:float
well_depth_setting()[source]

Returns a string describing the well-depth setting of the instrument

Returns:the well-depth setting
Return type:str

gemini_instruments.gemini.lookup module