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A satellite orbit prediction library.


We recommend using out-of-source builds.

mkdir build
cd build
cmake ..


make install

The install location is defined by CMAKE_INSTALL_PREFIX, which defaults to /usr/local. To relocate the whole installation (to make usr/local etc. inside another directory, e.g., if you want to make a tarball or package it afterwards), use make DESTDIR=/foo/bar install.


The library comes with pkg-config information, so the include and library paths and flags can be found using the pkg-config command or by using the PKG_CHECK_MODULES autotools macro or CMake command.


We recommend to investigate the examples under examples/ and the API documentation in include/predict/predict.h.

A condensed version is that

predict_orbital_elements_t *orbital_elements = orbital_elements = predict_parse_tle(tle_line_1, tle_line_2);

parses a TLE in the form of two char arrays to orbital elements representing a satellite, and that

predict_observer_t *observer = predict_create_observer(name, latitude_radians, longitude_radians, altitude_meters);

defines a QTH for observation. For prediction,

struct predict_position orbit;
predict_orbit(orbital_elements, &orbit, prediction_time);

can be used to calculate properties that are independent of an observer (longitude, latitude, ...), while

struct predict_observation observation;
predict_observe_orbit(observer, &orbit, &observation);

will convert to properties that will be relative to our observer (azimuth, elevation, ...).


Copyright 1991-2006 John A. Magliacane (KD2BD)

Copyright 2013- Akademisk radioklubb (LA1K)

Copyright 2013-2015 Knut Magnus Kvamtrø (LA3DPA)

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.