src/Atmosphere/AirDensity.hpp

   1 /*
   2 Copyright_License {
   3
   4   XCSoar Glide Computer - http://www.xcsoar.org/
   5   Copyright (C) 2000-2013 The XCSoar Project
   6   A detailed list of copyright holders can be found in the file "AUTHORS".
   7
   8   This program is free software; you can redistribute it and/or
   9   modify it under the terms of the GNU General Public License
  10   as published by the Free Software Foundation; either version 2
  11   of the License, or (at your option) any later version.
  12
  13   This program is distributed in the hope that it will be useful,
  14   but WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16   GNU General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with this program; if not, write to the Free Software
  20   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  21 }
  22 */
  23
  24 #ifndef XCSOAR_ATMOSPHERE_AIRDENSITY_H
  25 #define XCSOAR_ATMOSPHERE_AIRDENSITY_H
  26
  27 #include "Math/fixed.hpp"
  28
  29 /**
  30  * Calculates the air density from a given QNH-based altitude
  31  * @param altitude QNH-based altitude (m)
  32  * @return Air density (kg/m^3)
  33  */
  34 fixed AirDensity(const fixed altitude);
  35
  36 /**
  37  * Divide TAS by this number to get IAS
  38  * @param altitude QNH-based altitude (m)
  39  * @return Ratio of TAS to IAS
  40  */
  41 fixed AirDensityRatio(const fixed altitude);
  42
  43 #endif