helikite.processing.post.altitude
=================================

.. py:module:: helikite.processing.post.altitude


Functions
---------

.. autoapisummary::

   helikite.processing.post.altitude.Air_density
   helikite.processing.post.altitude.waterpressure
   helikite.processing.post.altitude.Watersatpress
   helikite.processing.post.altitude.EstimateAltitude
   helikite.processing.post.altitude.calculate_altitude_hypsometric_simple
   helikite.processing.post.altitude.calculate_altitude_for_row


Module Contents
---------------

.. py:function:: Air_density(T, P, RH=0)

   Calculate dry and wet air density using the ideal gas law.

   This function computes the dry air density from the ideal gas law based on
   a reference state and adjusts for moisture content using the water vapor
   pressure to yield the wet air density.

   :param T: Temperature in Kelvin.
   :type T: float
   :param P: Pressure in hPa.
   :type P: float
   :param RH: Relative humidity in percent (default is 0).
   :type RH: float, optional

   :returns:

             A tuple containing:
                 - dry air density in kg/m³
                 - wet air density in kg/m³
   :rtype: tuple of float

   .. rubric:: Notes

   The calculation uses standard reference conditions (rho0 = 1.29 kg/m³,
   P0 = 1013.25 hPa, T0 = 273.15 K) and applies an adjustment based on water
   vapor pressure.


.. py:function:: waterpressure(RH, T, P)

   Calculate the partial pressure of water vapor.

   This function determines the water vapor pressure given the relative
   humidity, temperature, and pressure. It computes the saturation vapor
   pressure and then scales it by the relative humidity.

   :param RH: Relative humidity in percent.
   :type RH: float
   :param T: Temperature in Kelvin.
   :type T: float
   :param P: Pressure in hPa.
   :type P: float

   :returns: Partial pressure of water vapor in hPa.
   :rtype: float


.. py:function:: Watersatpress(press, temp)

   Calculate water saturation vapor pressure for moist air.

   This function computes the saturation vapor pressure for water based on the
   WMO CIMO guide, valid for temperatures between -45°C and 60°C. The
   temperature is first converted from Kelvin to Celsius before applying the
   empirical formula.

   :param press: Pressure in hPa.
   :type press: float
   :param temp: Temperature in Kelvin.
   :type temp: float

   :returns: Saturation vapor pressure of water (H₂O) in hPa.
   :rtype: float

   .. rubric:: References

   https://www.wmo.int/pages/prog/www/IMOP/CIMO-Guide.html


.. py:function:: EstimateAltitude(P0, Pb, T0)

   Estimate the altitude difference using a barometric formula.

   This function calculates the altitude based on the reference pressure, the
   observed barometric pressure, and the reference temperature. A standard
   relative humidity of 50% is assumed to compute the wet air density used in
   the calculation.

   :param P0: Reference pressure in hPa.
   :type P0: float
   :param Pb: Observed barometric pressure in hPa.
   :type Pb: float
   :param T0: Reference temperature in Kelvin.
   :type T0: float

   :returns: Estimated altitude in meters.
   :rtype: float


.. py:function:: calculate_altitude_hypsometric_simple(p0, p, t)

   Calculate altitude using a simplified hypsometric equation.

   This function estimates altitude based on the hypsometric formula. It uses
   the reference pressure (p0), observed pressure (p), and temperature in
   Celsius (t) to compute the altitude.

   :param p0: Reference pressure in hPa.
   :type p0: float
   :param p: Observed pressure in hPa.
   :type p: float
   :param t: Temperature in Celsius.
   :type t: float

   :returns: Estimated altitude in meters.
   :rtype: float


.. py:function:: calculate_altitude_for_row(row)

   Calculate altitude from a data row of meteorological measurements.

   This function extracts pressure and temperature data from a dictionary-like
   object and computes the altitude using a simplified hypsometric formula.

   :param row:
               Data structure containing the following keys:
                   - "Pref": reference pressure in hPa.
                   - "P_baro": observed barometric pressure in hPa.
                   - "TEMP1": temperature in Celsius.
   :type row: dict-like

   :returns: Estimated altitude in meters.
   :rtype: float