lsst.sims.ocs.downtime.unscheduled_downtime module

class lsst.sims.ocs.downtime.unscheduled_downtime.UnscheduledDowntime

Bases: future.types.newobject.newobject

Handle creating the unscheduled downtime information.

This class handles the unscheduled downtime information.

Initialize the class.

__call__()

Return the top downtime.

__len__()

Return number of scheduled downtimes.

Returns:int

initialize(use_random_seed=False, random_seed=-1, survey_length=7300)

Configure the set of unscheduled downtimes.

This function creates the unscheduled downtimes based on a set of probabilities of the downtime type occurance. A default seed is used to produce the same set of downtimes, but a randomized seed can be requested.

The random downtime is calculated using the following probabilities:

minor event

remainder of night and next day = 5/365 days e.g. power supply failure

intermediate

3 nights = 2/365 days e.g. repair filter mechanism, rotator, hexapod, or shutter

major event

7 nights = 1/2*365 days

catastrophic event

14 nights = 1/3650 days e.g. replace a raft

Parameters:

• use_random_seed (bool, optional) – Flag to set the seed based on the current time. Default is to used fixed seed.
• random_seed (int, optional) – Provide an alternate random seed. Only works when use_random_seed is True.
• survey_length (int, optional) – The length of the survey in days. Default is the length of a 20 year survey.

CATASTROPHIC_EVENT = (0.000274, 14, 'catastrophic event')

INTERMEDIATE_EVENT = (0.00548, 3, 'intermediate event')

MAJOR_EVENT = (0.00137, 7, 'major event')

MINOR_EVENT = (0.0137, 1, 'minor event')

total_downtime

Get the total downtime (units=days).

Returns:int