The
'BSD-style'
license allows non-restrictive use for commercial and open source development.

- Facilitate many users by programming well and simply.
- Facilitate growth of the code.
- Allow users to get started easily and quickly.
- This library intends to provide simple but robust and efficient functions for solving GNSS problems.
- Facilitate this library becoming part of commercial and other open source applications.
- Facilitate university research.

- Program from the ground up using 'c' for simple applications and 'c++' for more complicated applications. The following figure illustrates this principle.
- Minimize dependancies - allows lots of simple applications from a small part of the core code base.
- All code must be well commented. Comments for variables include units. Comments for algorithms include academic references.
- All core code algorithms require a corresponding unit test.
- Avoid complicated programming concepts. Keep it Simple S.....
- Include an example code snippet in the comment block whenever possible.

- Non-restrictive license that allows inclusion in proprietary commercial software (BSD-style license).
- Algorithms are properly referenced.
- Thorough documentation. Always refer to the .h files.
- Units provided for each parameter in the documenation.

- Easy to interpret and configure the option file. click here for an example.
- Stand alone and differential modes.
- Least squares.
- Extended Kalman filtering.
- Estimates position, velocity, ambiguities, receiver clock offset and drift.
- Utilize pseudorange, Doppler, and accumulated Doppler range (ADR, also called carrier phase) measurements.
- Data containers: Receiver objects have an array of channel objects.
- Data containers utilize a simple C++ style with minimal encapsulation.
- Uses the Zenautics Matrix/Vector class library.

- Utilizes CUnit.
- Unit tests for all the core algorithms.
- Simple to understand, get started, and add tests.

- Compute coordinate conversion between Geodetic Curvilinear and Earth Centered Earth Fixed (ECEF)coordinates, 16 ellipsoids supported.
- Compute the Northing, Easting, and Vertical coordinates in a Local Geodetic Frame from Geodetic Curvilinear coordinates.
- Compute the difference in position between two points.
- Compute the Meridian Radius of Curvature.
- Compute the Prime Vertical Radius Of Curvature.
- Compute azimuth and elevation between ECEF points.
- and more... refer geodesy.h.

- Convert between UTC and GPS time.
- Compute Julian date.
- refer time_conversion.h

- Compute GPS satellite clock correction and clock drift correction.
- Compute GPS satellite position and velocity.
- Compute GPS satellite azimuth and elevation.
- Decode raw ephemeris data (subrame binary data).
- refer gps.h.

- Compute a closed form solution for GPS position using four pseudorange measurements.
- Compute the partial derivatives of range with respect to X, Y, Z or latitude, longitude, height.
- refer navigation.h.

- Compute the GPS broadcast ionospheric correction.
- refer ionosphere.h.

- Compute the tropospheric delay using the Wide Area Agumentation System Minimum Operation Standard (WAAS MOPS) model, more info.
- refer troposphere.h.

- Decode YUMA format almanac files for GPS... refer yuma.h.
- Decode SEM format almanac files for GPS... refer sem.h.
- Decode NovAtel OEM4 GPS data files... refer novatel.h.
- Decode RINEX version 2.1, 2.11... refer rinex.h

- RINEX version 2.1, 2.11 support
- Decode header information.
- Decode Observation files, one observation at a time.
- Decode Navigation files.
- refere rinex.h.

- Test data for cycle slips

- Uses the Zenautics Matrix/Vector class library.
- refer cmatrix.h. (c)
- refer Matrix.h. (c++)

- Download and install a subversion client. TortoiseSVN for Windows is recommended. Otherwise click here .
- Make a folder, call it gnsstk.
- Right click on the folder and select "SVN Checkout".
- The URL of the repository is https://gnsstk.svn.sourceforge.net/svnroot/gnsstk/trunk. Leave the checkout window options as default. Check out the HEAD revision.
- Anonymous download is allowed.
- To get write access to the repository, you have to become a developer. You'll need a sourceforge account first, click here. Then email the project administrator, glenn_macgougan at users.sourceforge.net.

Copyright (c) 2007, refer to 'author' doxygen tags in the source code

Point of Contact: Glenn D. MacGougan <glenn_macgougan at users.sourceforge.net>

Redistribution and use in source and binary forms, with or without modification, are permitted provided the following conditions are met:

- Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

- Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

- The name(s) of the contributor(s) may not be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.