v1.6.0

[attipaci]

Feature release, introducing a proper C++ API for the first time, adding the self-contained semi-analytic ELP2000 / MPP02 model of the Moon, and bringing various other improvements.

Fixed

• Incorrect ICRS observer location in airborne observing frames #293: geo_posvel() applied TOD to ICRS conversions twice for airborne observers, resulting in imprecise observer coordinates relative to the geocenter.

• buffer overflow in novas_print_dms #296: Possible buffer overflow in novas_print_dms(). (thanks to @aleberti)

• novas_geom_posvel() returned velocities referenced to SSB, not observer #305: novas_geom_posvel() returned velocities referenced to SSB, not to the observer.

Added

• Developing a true C++ API... #256: New C++11 API to wrap the C99 functions into a higher-level, easier to use, and object-oriented interface. (thanks to @aleberti for helping with testing and debugging).

• Developing a true C++ API... #256: New novas_time_leap() to simplify back calculating the leap seconds from a novas_timespec structure.

• ELP2000/MPP02 semi-analytic model of Moon vs Earth. #281: Added a truncated version of semi-analytic ELP/MPP02 model of the Moon's position relative to the geocenter by Chapront & Francou (2003), using up to about 3400 terms, and reaching accuracies to the 1 arcsec / 1km level (or better for the present era).

• Add cspice_clear_kernels() #298: Added cspice_clear_kernels() to CSPICE plugin to close all kernels and free up the resources they use (thanks to @aleberti)

• NOVAS C geo_posvel() is imprecise for Earth-based observers #306: Added novas_site_gcrs_posvel() as a more precise alternative to geo_posvel() for Earth-bound observers, when polar wobble offsets are known.

• Added novas_enu_to_itrs() and novas_itrs_to_enu() functions to help convert between local East-North-Up (ENU) coordinates and ITRS. ENU is a natural local Cartesian coordinate system of an observer at or near the Earth's surface.

• Added novas_diff_time_scale() for obtaining time difference between two astrometric times in the specified timescale of choice.

• Added novas_timescale_offset() for returning the time offset in two different timescale representations of a time instance.

• Added novas_icrs_to_sys() and novas_sys_to_icrs() for more flexible conversion of equatorial vectors between ICRS/GCRS and other coordinate reference systems.

Changed

• Developing a true C++ API... #256: Changes to repo layout to accommodate C++ API in addition to the base C99 API.

• NOVAS C geo_posvel() is imprecise for Earth-based observers #306: novas_make_frame() now uses the new novas_site_gcrs_posvel() when calculating SSB-based observer location and velocity, in the GCRS, for Earth-based observers.

• NOVAS C geo_posvel() is imprecise for Earth-based observers #306: geo_posvel() changed to return an error (-1) if used for a geodetic observer and debug mode is set to NOVAS_DEBUG_EXTRA, to warn that polar offsets are not included in the calculation.

• CMake alternative math library detection #310: Change how CMake detects the need for linking against libm.

• Use more precise matrix from Liu et al. (2011) for equatorial / galactic conversions.

• Consolidated equatorial vector transformations, eliminating duplicated code.

• CMake config updated to link libraries against dependent libraries with PUBLIC scope, and other configuration tweaks.

• Improved and updated documentation.

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This discussion was created from the release v1.6.0.