3. DopplerIdeal#

class DopplerIdeal(name: str, instrument: Instrument, sigma: ArrayWUnits = None, state_definition: list = None, sequence_definition=None, antenna_name: str = None, doppler_transmit_frequency: ArrayWUnits = None, ground_station_2: GroundStation = None)#

Bases: Measurement

Generates doppler observables between an observer and a target.

This ideal doppler model assumes:

no light-time for signal traveling around
no media effects (tropo/iono)
antenna is positioned as in the center of mass of the spacraft
the spacraft is not spinning

Parameters:

name (str) – The name of the measurement model.
instrument (Instrument) – An “antenna” instrument is used for radiometric measurement models.
sigma (ArrayWUnits, optional) – Measurement standard deviation. Defaults to None.
state_definition (list, optional) – StateVector definition list. Optional, defaults to None.
sequence_definition (list, optional) – sequence definition list. Optional, defaults to None.
antenna_name (str, optional) – Name of the antenna on which the measurement model works. Used to read antenna characteristics. Optional, defaults to None.
doppler_transmit_frequency (ArrrayWUnits, optional) – Transmit frequency for doppler. Optional, defaults to None.
ground_station_2 (GroundStation, optional) – Second ground station for three-way doppler. Optional, defaults to None.

:raises RuntimeError(`'The model name should consistently begin with 'GS``’ followed by a number and a space (e.g., ‘GS1 ``', '``GS2 ``') to designate the order of ground stations. The provided name does not adhere to this criterion.'): | Raised when the name for the measurement model is not consistent with standardized notation used across the rest of the code. :raises RuntimeError(``’multiple units are extracted from the measurements.’:py:class:`): | Raised when the units extracted from the measurements are not consistent with each other. :raises RuntimeError(`’Please provide an EpochArray or provide start and end Epochs.’``:py:class:`): | Raised when the time on which to generate measurements is not an EpochArray object or is not passed as a begin and end pair.

See also

scarabaeus.Measurement: parent class of each specific measurement model.

Attributes

`antenna_name`	The name of the antenna.
`doppler_transmit_frequency`	The Doppler transmission frequency
`ground_station_2`	The second ground station.
`gs_number`	The ground station number.
`instrument`	The instrument.
`name`	The name of the model.
`sequence_definition`	The sequence definition.
`sigma`	The standard deviation of the measurement model.
`state_definition`	The state vector definition.

Methods

`compute_h_tilde_dv_man`(relative_state)	Generates the portion in the h_tilde matrix relative to the partial of the ideal doppler measurement model with respect to the maneuver DV components.
`compute_h_tilde_eta_srp`()	Generates the portion in the h_tilde matrix relative to the partial of the ideal doppler measurement model with respect to the srp scaling factor (eta_srp).
`compute_h_tilde_gs_location`(relative_state)	Generates the portion in the h_tilde matrix relative to the partial of the ideal doppler measurement model with respect to the ground station position components.
`compute_h_tilde_pos`(relative_state)	Generates the portion in the h_tilde matrix relative to the partial of the ideal doppler measurement model with respect to the position components.
`compute_h_tilde_range_bias`()	Generates the portion in the h_tilde matrix relative to the partial of the ideal doppler measurement model with respect to the range bias.
`compute_h_tilde_vel`(relative_state)	Generates the portion in the h_tilde matrix relative to the partial of the ideal doppler measurement model with respect to the velocity components.
`compute_partials`(target, epoch_array[, frame])	Stacks together measurement partials for an epoch array at different epochs.
`computed_measurements`(target[, epoch_array, ...])	Computs the doppler measurement between target.name and self.instrument.name (2-way doppler).
`generate_measurement_dataset`(dataset_name, ...)	Generates a MeasurementDataSet object that can be used by filters downstream.
`observed_measurements`(file_name[, ...])	Reads measurements from a .json file.
`partials`(target, epoch, frame)	Groups toghether the different components of measurement partials in the global H-tilde.
`residuals`(observed_meas, computed_meas)	Generates the measurement model's residuals given observed and computed ArrayWFrames.
`write_observed_measurements`(target[, ...])	Generates synthetic measurements and write them as a .json file.

compute_h_tilde_dv_man(relative_state: ArrayWUnits) → ndarray#

Generates the portion in the h_tilde matrix relative to the partial of the ideal doppler measurement model with respect to the maneuver DV components.

Parameters:: relative_state (ArrayWUnits) – The relative state between self and the target.
Returns:: np.array
Return type:: The (3,) vector the partial derivatives of the measurement model by the maneuver DV components

References