## Subsystem Airdata1

Airdata1 computes the speed of sound a, the Mach number M, and the dynamic pressure qdyn. The block Airdata1 is contained in the subsystem Airdata Group of the Beaver model. Other airdata (-related) variables are computed in the blocks Atmosph, Airdata2, and Airdata3, which also contained in the subsystem Airdata Group.

### Inputvectors: x and yatm

      x    = [V alpha beta p q r psi theta phi xe ye H]'     (states)
      yatm = [rho ps T mu g]'   (atmospheric properties, computed in
                                                   the block Atmosph)

      V    : airspeed [m/s]
     {alpha: angle of attack [rad]                                  }
     {beta : sideslip angle [rad]                                   }
     {p    : roll rate [rad/s]                                      }
     {q    : pitch rate [rad/s]                                     }
     {r    : yaw rate [rad/s]                                       }
     {psi  : yaw angle [rad]                                        }
     {theta: pitch angle [rad]                                      }
     {phi  : roll angle [rad]                                       }
     {xe   : x-coordinate in Earth-fixed reference frame [m]        }
     {ye   : y-coordinate ''     ''          ''      ''  [m]        }
     {H    : altitude above sea-level [m]                           }

      rho  : airdensity [kg/m^3]
     {ps   : static pressure [N/m^2]                                }
      T    : temperature [K]
     {mu   : dynamic viscosity [kg/(m*s)]                           }
     {g    : acceleration of gravity [m/s^2]                        }

The inputvariables which are not actually used by Airdata1 have been displayed between curly braces.

### Outputvector: yad1

      yad1 = [a M qdyn]'

      a    : speed of sound [m/s]
      M    : Mach number [-]
      qdyn : dynamic pressure [N/m^2]