HighVelocityNightsMetric¶
- class rubin_sim.maf.metrics.HighVelocityNightsMetric(psf_factor=2.0, n_obs_per_night=2, snr_limit=None, velocity_col='velocity', **kwargs)¶
Bases:
BaseMoMetric
Count the number of discovery opportunities (via trailing) for an SSobject.
Determine the first time an asteroid is observed is observed with a velocity high enough to make it appear trailed by a factor of psf_factor*PSF with n_obs_per_night observations within a given night.
- Parameters:
- psf_factor: float, optional
Object velocity (deg/day) must be >= 24 * psf_factor * seeingGeom (”) / visitExpTime (s). Default is 2 (i.e. object trailed over 2 psf’s).
- n_obs_per_night: int, optional
Number of observations per night required. Default 2.
- snr_limit: float or None
If snr_limit is set as a float, then requires object to be above snr_limit SNR in the image. If snr_limit is None, this uses the probabilistic ‘visibility’ calculated by the vis stacker, which means SNR ~ 5. Default is None.
- velocity_col: str, optional
Name of the velocity column in the obs file. Default ‘velocity’. (note this is deg/day).
- Returns:
- float
The time of the first detection where the conditions are satisifed.
Methods Summary
run
(sso_obs, orb, hval)Calculate the metric value.
Methods Documentation
- run(sso_obs, orb, hval)¶
Calculate the metric value.
- Parameters:
- sso_obs: np.ndarray
The input data to the metric (same as the parent metric).
- orb: np.ndarray
The information about the orbit for which the metric is being calculated.
- hvalfloat
The H value for which the metric is being calculated.
- Returns:
- float or np.ndarray or dict