Source code for pyswice_spk_utilities

#
#  ISC License
#
#  Copyright (c) 2016, Autonomous Vehicle Systems Lab, University of Colorado at Boulder
#
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import numpy
# -------------------------------------------------------------
#
# ... SPKReader.py
#
# ... Purpose - Read a SPICE SPK file to provide Ephemeris
# ...           object state
#
# ... Input:
# ...            target - name of the target body, can be ID or object name
# ...            time - UTC Gregorian time string at the desired instance
# ...            ref - Reference frame string
# ...            observer - name of the observing body
#
# ... Output:
# ...            state - position and velocity vector
# ...                    first 3 values are position cartesian coordinates
# ...                    last 3 values are velocity components
# ...            lt - light time in seconds
#
# ... G. D. Chapel     LASP             27 Jun 2016
# ...                  ADCS Team
# ...
# --------------------------------------------------------------
from Basilisk.topLevelModules import pyswice


[docs]def spkRead(target, time, ref, observer): """Spice spk read method""" et = pyswice.new_doubleArray(1) pyswice.str2et_c(time, et) state = pyswice.new_doubleArray(6) lt = pyswice.new_doubleArray(1) pyswice.spkezr_c(target, pyswice.doubleArray_getitem(et, 0), ref, "NONE", observer, state, lt) stateArray = numpy.zeros(6) lightTime = pyswice.doubleArray_getitem(lt, 0) for i in range(6): stateArray[i] = pyswice.doubleArray_getitem(state, i) pyswice.delete_doubleArray(state) pyswice.delete_doubleArray(lt) pyswice.delete_doubleArray(et) return stateArray