!! Constant values and factors for the conversion from 
!    non SI units to SI units
!|author:  <a href="mailto:giovanni.ravazzani@polimi.it">Giovanni Ravazzani</a>
! license: <a href="http://www.gnu.org/licenses/">GPL</a>
!    
!### History
!
! current version  1.1 - 20th July 2018
!
! | version  |  date       |  comment |
! |----------|-------------|----------|
! | 1.0      | 09/Jul/2008 | Original code |
! | 1.1      | 20/Jul/2018 | added NaN |
!
!
!### License  
! license: GNU GPL <http://www.gnu.org/licenses/>
!
! This file is part of 
!
!   MOSAICO -- MOdular library for raSter bAsed hydrologIcal appliCatiOn.
! 
!   Copyright (C) 2011 Giovanni Ravazzani
!
!### Code Description 
!   Language:           Fortran 90. 
!
!   Software Standards: "European Standards for Writing and  
!   Documenting Exchangeable Fortran 90 Code". 
! 
!### Module Description 
!   It provides constant values and factor for the conversion from 
!    non SI units to SI units
!
! References and Credits:
!   SI_units module by Grant W. Petty.
!
MODULE Units        

! Modules used: 
! 
USE DataTypeSizes, ONLY : & 
    ! Imported Parameters:
    float, double, short

IMPLICIT NONE 

! Global (i.e. public) Declarations: 

! Constants of nature
REAL(KIND = double), PUBLIC, PARAMETER :: pi = 3.141592653589793_double
REAL(KIND = double), PUBLIC, PARAMETER :: speedOfLight = 2.99792458E+8_double !! (m/s)
REAL(KIND = float ), PUBLIC, PARAMETER :: stefanBoltzman = 5.670367E-8_float !! ( watt/ (m2 * kelvin) )
REAL(KIND = float ), PUBLIC, PARAMETER :: gravityAccel = 9.80665_float !( m/s2 )
REAL(KIND = float ), PUBLIC, PARAMETER :: icePoint = 273.15_float !( k )
REAL(KIND = float ), PUBLIC, PARAMETER :: waterTriplePoint = 273.16_float !( k )

! Units of length [m]
REAL(KIND = double), PUBLIC, PARAMETER :: angstrom = 1E-10_double
REAL(KIND = double), PUBLIC, PARAMETER :: micron = 1E-6_double
REAL(KIND = float ), PUBLIC, PARAMETER :: millimeter = 1E-3_float
REAL(KIND = float ), PUBLIC, PARAMETER :: mm = 1E-3_float !abbreviation
REAL(KIND = float ), PUBLIC, PARAMETER :: centimeter = 1E-2_float
REAL(KIND = float ), PUBLIC, PARAMETER :: cm = 1E-2_float !abbreviation
REAL(KIND = float ), PUBLIC, PARAMETER :: kilometer = 1E+3_float
REAL(KIND = float ), PUBLIC, PARAMETER :: km = 1E+3_float !abbreviation
REAL(KIND = float ), PUBLIC, PARAMETER :: nauticalMile = 1.852E+3_float
REAL(KIND = float ), PUBLIC, PARAMETER :: inch = 2.54 * cm
REAL(KIND = float ), PUBLIC, PARAMETER :: foot = 12.0 * inch
REAL(KIND = float ), PUBLIC, PARAMETER :: yard = 3.0 * foot
REAL(KIND = float ), PUBLIC, PARAMETER :: mile = 5280.0 * foot

! Units of area [m2]
REAL(KIND = float ), PUBLIC, PARAMETER :: squareMillimeter = millimeter ** 2_float
REAL(KIND = float ), PUBLIC, PARAMETER :: mm2 = millimeter ** 2_float !abbreviation
REAL(KIND = float ), PUBLIC, PARAMETER :: squareCentimeter = centimeter ** 2_float
REAL(KIND = float ), PUBLIC, PARAMETER :: cm2 = centimeter ** 2_float !abbreviation
REAL(KIND = float ), PUBLIC, PARAMETER :: squareKilometer = kilometer ** 2_float
REAL(KIND = float ), PUBLIC, PARAMETER :: km2 = kilometer ** 2_float !abbreviation
REAL(KIND = float ), PUBLIC, PARAMETER :: hectare = 1E+4_float
REAL(KIND = float ), PUBLIC, PARAMETER :: ha = 1E+4_float !abbreviation
REAL(KIND = float ), PUBLIC, PARAMETER :: squareInch = inch ** 2_float
REAL(KIND = float ), PUBLIC, PARAMETER :: squareFoot = foot ** 2_float
REAL(KIND = float ), PUBLIC, PARAMETER :: squareYard = yard ** 2_float
REAL(KIND = float ), PUBLIC, PARAMETER :: squareMile = mile ** 2_float
REAL(KIND = float ), PUBLIC, PARAMETER :: acre = 4356_float * squareFoot

! Units of volume [m3]
REAL(KIND = float ), PUBLIC, PARAMETER :: liter = 1E-3_float
REAL(KIND = float ), PUBLIC, PARAMETER :: cubicCentimeter = centimeter ** 3_float
REAL(KIND = float ), PUBLIC, PARAMETER :: cc = centimeter ** 3_float !abbreviation
REAL(KIND = float ), PUBLIC, PARAMETER :: milliLiter = centimeter ** 3_float !synonym
REAL(KIND = float ), PUBLIC, PARAMETER :: cubicInch = inch ** 3_float
REAL(KIND = float ), PUBLIC, PARAMETER :: cubicFoot = foot ** 3_float
REAL(KIND = float ), PUBLIC, PARAMETER :: imperialGallon = 4.54609_float * liter
REAL(KIND = float ), PUBLIC, PARAMETER :: usaGallon = 3.785412_float * liter
REAL(KIND = float ), PUBLIC, PARAMETER :: quart = usaGallon / 4_float
REAL(KIND = float ), PUBLIC, PARAMETER :: pint = usaGallon / 8_float
REAL(KIND = float ), PUBLIC, PARAMETER :: cup = usaGallon / 16_float
REAL(KIND = float ), PUBLIC, PARAMETER :: ounce = usaGallon / 128_float
REAL(KIND = float ), PUBLIC, PARAMETER :: tableSpoon = usaGallon / 256_float
REAL(KIND = float ), PUBLIC, PARAMETER :: teaSpoon = usaGallon / 768_float

! Units of time [s]
REAL(KIND = float ), PUBLIC, PARAMETER :: minute = 60_float 
REAL(KIND = float ), PUBLIC, PARAMETER :: hour = 60_float * minute
REAL(KIND = float ), PUBLIC, PARAMETER :: day = 24_float * hour
REAL(KIND = float ), PUBLIC, PARAMETER :: week = 7_float * day
REAL(KIND = float ), PUBLIC, PARAMETER :: month = 30.416666667_float * day
REAL(KIND = float ), PUBLIC, PARAMETER :: year = 365_float * day


! Conversion factor
REAL(KIND = float), PUBLIC, PARAMETER :: degToRad = pi / 180_float !!Degree to radians
REAL(KIND = float), PUBLIC, PARAMETER :: radToDeg = 180_float / pi !!Degree to radians 

!NaN values
REAL (KIND = float), PUBLIC, PARAMETER ::NaNreal = -9999.9
INTEGER (KIND = short), PUBLIC, PARAMETER ::NaNint = -9999

END MODULE Units