libera_utils.time#

Module for dealing with time and time conventions

Some convention for this module

1. Only decorate direct spiceypy wrapper functions with the ensure_spice decorator. They should directly call a spiceypy function.

2. All spiceypy wrapper functions should read as <spiceypyfunc>_wrapper. We really only use these to allow array inputs for spiceypy functions that aren’t already vectorized in C and to wrap them in ensure_spice.

All functions should have robust type-hinting.

Functions

`convert_cds_integer_to_datetime`(satellite_time)	Helper function to convert a satellite time given as an CCSDS Day Segmented Time Code (CDS) form as 8 byte integer to a timezone aware datetime object
`et2utc_wrapper`(et, fmt, prec)	Convert ephemeris times to UTC ISO strings.
`et_2_datetime`(et)	Convert ephemeris time to a python datetime object by first converting it to a UTC timestamp.
`et_2_timestamp`(et[, fmt])	Convert ephemeris time to a custom formatted timestamp (default is lowercase version of ISO).
`sce2s_wrapper`(et)	Convert ephemeris times to SCLK string https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/sce2s_c.html Decorated wrapper for spiceypy.sce2s that will automatically furnish the latest metakernel and retry if the first call raises an exception.
`scs2e_wrapper`(sclk_str)	Convert SCLK strings to ephemeris time.
`utc2et_wrapper`(iso_str)	Convert UTC ISO strings to ephemeris times.

libera_utils.time.convert_cds_integer_to_datetime(satellite_time: int)#

Helper function to convert a satellite time given as an CCSDS Day Segmented Time Code (CDS) form as 8 byte integer to a timezone aware datetime object

Parameters:: satellite_time (int) – A 64-bit unsigned integer that represents CDS time
Returns:: cds_time
Return type:: datetime.datetime

libera_utils.time.et2utc_wrapper(et: float | Collection[float] | ndarray, fmt: str, prec: int) → str | Collection[str]#

Convert ephemeris times to UTC ISO strings. https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/et2utc_c.html Decorated wrapper for spiceypy.et2utc that will automatically furnish the latest metakernel and retry if the first call raises an exception.

Parameters:

et (Union[float, Collection[float], numpy.ndarray]) – The ephemeris time value to be converted to UTC.
fmt (str) – Format string defines the format of the output time string. See CSPICE docs.
prec (int) – Number of digits of precision for fractional seconds.

Returns:

UTC time string(s)

Return type:

Union[numpy.ndarray, str]

libera_utils.time.et_2_datetime(et: float | Collection[float] | ndarray) → datetime | ndarray#

Convert ephemeris time to a python datetime object by first converting it to a UTC timestamp.

Parameters:: et (float or Collection or numpy.ndarray) – Ephemeris times to be converted.
Returns:: Object representation of ephemeris times.
Return type:: datetime.datetime or numpy.ndarray

libera_utils.time.et_2_timestamp(et: float | Collection[float] | ndarray, fmt: str = '%Y%m%dT%H%M%S.%f') → str | Collection[str]#

Convert ephemeris time to a custom formatted timestamp (default is lowercase version of ISO).

Parameters:

et (Union[float, Collection[float], numpy.ndarray]) – Ephemeris Time to be converted.
fmt (str, Optional) – Format string as defined by the datetime.strftime() function.

Returns:

Formatted timestamps

Return type:

Union[str, Collection[str]]

libera_utils.time.sce2s_wrapper(et: float | Collection[float] | ndarray) → str | ndarray#

Convert ephemeris times to SCLK string https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/sce2s_c.html Decorated wrapper for spiceypy.sce2s that will automatically furnish the latest metakernel and retry if the first call raises an exception.

Parameters:: et (Union[float, Collection[float], numpy.ndarray]) – Ephemeris time
Returns:: SCLK string
Return type:: Union[str, Collection[str]]

libera_utils.time.scs2e_wrapper(sclk_str: str | Collection[str]) → float | ndarray#

Convert SCLK strings to ephemeris time. https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/scs2e_c.html Decorated wrapper for spiceypy.scs2e that will automatically furnish the latest metakernel and retry if the first call raises an exception.

Parameters:: sclk_str (Union[str, Collection[str]]) – Spacecraft clock string
Returns:: Ephemeris time
Return type:: Union[float, numpy.ndarray]

libera_utils.time.utc2et_wrapper(iso_str: str | Collection[str]) → float | ndarray#

Convert UTC ISO strings to ephemeris times. https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/utc2et_c.html Decorated wrapper for spiceypy.utc2et that will automatically furnish the latest metakernel and retry if the first call raises an exception.

Parameters:: iso_str (Union[str, Collection[str]]) – The UTC to convert to ephemeris time
Returns:: Ephemeris time
Return type:: float or numpy.ndarray