AUTHOR=Kalafatoglu Eyiguler E. Ceren , Holley Warren , Howarth Andrew D. , Danskin Donald W. , Pandey Kuldeep , Martin Carley J. , Gillies Robert G. , Yau Andrew W. , Hussey Glenn C. 

TITLE=cavsiopy: a Python package to calculate and visualize spacecraft instrument orientation

JOURNAL=Frontiers in Astronomy and Space Sciences

VOLUME=10

YEAR=2023

URL=https://www.frontiersin.org/journals/astronomy-and-space-sciences/articles/10.3389/fspas.2023.1278794

DOI=10.3389/fspas.2023.1278794

ISSN=2296-987X

ABSTRACT=<p>Spacecraft attitude plays an important role in the observations of various atmospheric, planetary, and terrestrial parameters and phenomena that are of interest to the scientific community. Precise measurements from imagers, particle sensors, and antennas require accurate knowledge of instrument orientation. <italic>cavsiopy</italic> is an easy-to-install and use, light-weight open-source Python package for researchers who need to consider instrument pointing direction and observation geometry. <italic>cavsiopy</italic> contains the coordinate transformation routines and the corresponding rotation matrices from the spacecraft orbital reference frame (ORF) to any of the geocentric equatorial inertial for epoch J2000 (GEI J2K)/International Celestial Reference Frame (ICRF), Earth-centered, Earth-fixed (ECEF), International Terrestrial Reference Frame (ITRF), geodetic north-east-down, and geocentric north-east-center coordinate systems. Additionally, <italic>cavsiopy</italic> includes routines for importing Swarm-E ephemeris and generic two-line-element (TLE) data files; for the calculation of spacecraft azimuth, elevation, and orbital parameters; as well as for the 2D/3D visualization of the geometry between the instrument and the target. Functionality and utilization of <italic>cavsiopy</italic> for research problems are demonstrated with examples and visualizations for the Radio Receiver Instrument (RRI) and the Fast Auroral Imager (FAI) of e-POP/Swarm-E.</p>