troposphere.c File Reference

---

Detailed Description

GNSS core 'c' function library: GPS tropospheric calculations.

Author:

Glenn D. MacGougan (GDM)

Date:

2007-11-29

Since:

2005-08-22

REFERENCES

• RTCA, 2001. MINIMUM OPERATIONAL PERFORMANCE STANDARDS FOR GLOBAL POSITIONING SYSTEM/WIDE AREA AUGMENTATION SYSTEM AIRBORNE EQUIPMENT. RTCA/DO-229C. Prepared by SC-159. November 28, 2001. Supersedes DO-229B. Available at http://www.rtca.org/doclist.asp . pp. 338-340 of 586 in PDF.
  
• Guo, J. and R. B. Langely 2003. A New Tropospheric Propagation Delay Mapping Function for Elevation Angles Down to 2 degrees. ION GPS 2003, 9-12 Sept. 2003, Portland OR.
  
• Parkinson, B. and J. J. Spilker (1996). Global Positioning System: Theory And Applications Volume 1. American Institute of Aeronautics and Astronautics, Inc., Washinton D.C.
  

"LICENSE INFORMATION"
Copyright (c) 2007, refer to 'author' doxygen tags
All rights reserved.

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.

Definition in file troposphere.c.

#include <math.h>
#include "troposphere.h"
#include "constants.h"

Go to the source code of this file.

Functions
void	TROPOSPHERE_DetermineZenithDelayValues_WAAS_Model (const double latitude, const double height, const unsigned short dayofyear, double *zenith_dry_delay, double *zenith_wet_delay)
void	TROPOSPHERE_GetDryAndWetDelay_UsingThe_UNBabc_MappingFunction (const double zenith_dry_delay, const double zenith_wet_delay, const double elevation, const double latitude, const double height, double *drydelay, double *wetdelay)

---

Function Documentation

void TROPOSPHERE_DetermineZenithDelayValues_WAAS_Model	(	const double	latitude,
		const double	height,
		const unsigned short	dayofyear,
		double *	zenith_dry_delay,
		double *	zenith_wet_delay
	)

Computes the dry and wet zenith delays based on the WAAS model in the reference below.

Author:

Glenn D. MacGougan (GDM)

Date:

2005-08-22

Since:

2005-08-22

REFERENCES
[1] RTCA, 2001. MINIMUM OPERATIONAL PERFORMANCE STANDARDS FOR GLOBAL POSITIONING SYSTEM/WIDE AREA AUGMENTATION SYSTEM AIRBORNE EQUIPMENT. RTCA/DO-229C. Prepared by SC-159. November 28, 2001. Supersedes DO-229B. Available at http://www.rtca.org/doclist.asp . pp. 338-340 of 586 in PDF

Parameters:

latitude	user latitude [rad]
height	user height [m]
dayofyear	day of year (1-366) [days]
zenith_dry_delay	dry zenith delay [m]
zenith_wet_delay	wet zenith delay [m]

Definition at line 150 of file troposphere.c.

void TROPOSPHERE_GetDryAndWetDelay_UsingThe_UNBabc_MappingFunction	(	const double	zenith_dry_delay,
		const double	zenith_wet_delay,
		const double	elevation,
		const double	latitude,
		const double	height,
		double *	drydelay,
		double *	wetdelay
	)

Computes the dry and wet delays given the delay zenith values using the UNBabc Mapping function, described in [1], which requires elevation angle, latitude and height.

Author:

Glenn D. MacGougan (GDM)

Date:

2005-08-22

Since:

2005-08-22

REFERENCES
[1] Guo, J. and R. B. Langely 2003. A New Tropospheric Propagation Delay Mapping Function for Elevation Angles Down to 2 degrees. ION GPS 2003, 9-12 Sept. 2003, Portland OR

Parameters:

zenith_dry_delay	dry zenith delay [m]
zenith_wet_delay	wet zenith delay [m]
elevation	satellite elevation angle (must be >= 2 deg) [rad]
latitude	user latitude [rad]
height	user height (orthometric, ie above sea level) [m]
drydelay	dry delay mapped to this elevation angle [m]
wetdelay	wet delay mapped to this elevation angle [m]

Definition at line 245 of file troposphere.c.