GDS wizard for mercator cylindrical. More...

Data Types
type	ip_mercator_grid

Functions/Subroutines
subroutine	gdswzd_mercator (self, IOPT, NPTS, FILL, XPTS, YPTS, RLON, RLAT, NRET, CROT, SROT, XLON, XLAT, YLON, YLAT, AREA)
	GDS wizard for mercator cylindrical. More...

subroutine	init_grib1 (self, g1_desc)
	Initializes a mercator grid given a grib1_descriptor object. More...

subroutine	init_grib2 (self, g2_desc)
	Init GRIB2. More...

subroutine	mercator_grid_area (RLAT, AREA)
	Grid box area for mercator cylindrical grids. More...

subroutine	mercator_map_jacob (RLAT, XLON, XLAT, YLON, YLAT)
	Map jacobians for mercator cylindrical grids. More...

subroutine	mercator_vect_rot (CROT, SROT)
	Vector rotation fields for mercator cylindrical grids. More...

Variables
real	dlon
	Longitudinal direction grid length. More...

real	dphi
	Latitudinal direction grid length. More...

real	rerth
	Radius of the Earth. More...

Detailed Description

GDS wizard for mercator cylindrical.

Octet numbers refer to GRIB2 - GRID DEFINITION TEMPLATE 3.10 - Mercator.

Author: Iredell

Date: 96-04-10

Function/Subroutine Documentation

◆ gdswzd_mercator()

subroutine ip_mercator_grid_mod::gdswzd_mercator	(	class(ip_mercator_grid), intent(in)	self,
		integer, intent(in)	IOPT,
		integer, intent(in)	NPTS,
		real, intent(in)	FILL,
		real, dimension(npts), intent(inout)	XPTS,
		real, dimension(npts), intent(inout)	YPTS,
		real, dimension(npts), intent(inout)	RLON,
		real, dimension(npts), intent(inout)	RLAT,
		integer, intent(out)	NRET,
		real, dimension(npts), intent(out), optional	CROT,
		real, dimension(npts), intent(out), optional	SROT,
		real, dimension(npts), intent(out), optional	XLON,
		real, dimension(npts), intent(out), optional	XLAT,
		real, dimension(npts), intent(out), optional	YLON,
		real, dimension(npts), intent(out), optional	YLAT,
		real, dimension(npts), intent(out), optional	AREA
	)

private

GDS wizard for mercator cylindrical.

This routine decodes the grib 2 grid definition template (passed in integer form as decoded by the ncep g2 library) and returns one of the following:

(iopt=+1) earth coordinates of selected grid coordinates
(iopt=-1) grid coordinates of selected earth coordinates

Works for mercator cylindrical projections.

If the selected coordinates are more than one gridpoint beyond the the edges of the grid domain, then the relevant output elements are set to fill values.

The actual number of valid points computed is returned too.

Optionally, the vector rotations, map jacobians and the grid box areas may be returned. To compute the vector rotations, the optional arguments 'srot' and 'crot' must be present. To compute the map jacobians, the optional arguments 'xlon', 'xlat', 'ylon', 'ylat' must be present. to compute the grid box areas, the optional argument 'area' must be present.

Program History Log

Date	Programmer	Comments
96-04-10	iredell	Initial
96-10-01	iredell	protected against unresolvable points
97-10-20	iredell	include map options
2015-01-21	gayno	merger of gdswiz01() and gdswzd01(). Make crot,sort,xlon,xlat,ylon,ylat and area optional arguments. Make part of a module. move vector rotation, map jacobian and grid box area computations to separate subroutines.
2015-07-13	gayno	convert to grib 2. replace grib 1 kgds array with grib 2 grid definition template array. Rename.
2018-07-20	wesley	add threads.

Parameters

[in]	self	grid descriptor.
[in]	iopt	option flag 1 to compute earth coords of selected grid coords -1 to compute grid coords of selected earth coords
[in]	npts	maximum number of coordinates
[in]	fill	fill value to set invalid output data (must be impossible value; suggested value: -9999.)
[in,out]	xpts	(npts) grid x point coordinates if iopt>0
[in,out]	ypts	(npts) grid y point coordinates if iopt>0
[in,out]	rlon	(npts) earth longitudes in degrees e if iopt<0 (acceptable range: -360. to 360.)
[in,out]	rlat	(npts) earth latitudes in degrees n if iopt<0 (acceptable range: -90. to 90.)
[out]	nret	number of valid points computed
[out]	crot	optional (npts) clockwise vector rotation cosines
[out]	srot	optional (npts) clockwise vector rotation sines (ugrid=crotuearth-srotvearth; vgrid=srotuearth+crotvearth)
[out]	xlon	optional (npts) dx/dlon in 1/degrees
[out]	xlat	optional (npts) dx/dlat in 1/degrees
[out]	ylon	optional (npts) dy/dlon in 1/degrees
[out]	ylat	optional (npts) dy/dlat in 1/degrees
[out]	area	optional (npts) area weights in m**2 (proportional to the square of the map factor)

Author: Iredell

Date: 96-04-10

Definition at line 198 of file ip_mercator_grid_mod.F90.

References dlon, dphi, mercator_grid_area(), mercator_map_jacob(), mercator_vect_rot(), and rerth.

◆ init_grib1()

subroutine ip_mercator_grid_mod::init_grib1	(	class(ip_mercator_grid), intent(inout)	self,
		type(grib1_descriptor), intent(in)	g1_desc
	)

private

Initializes a mercator grid given a grib1_descriptor object.

Parameters

[in,out]	self	ip_mercator_grid object.
[in]	g1_desc	GRIB1 descriptor.

Author: Iredell

Date: 96-04-10

Definition at line 52 of file ip_mercator_grid_mod.F90.

References ip_constants_mod::dpr.

◆ init_grib2()

subroutine ip_mercator_grid_mod::init_grib2	(	class(ip_mercator_grid), intent(inout)	self,
		type(grib2_descriptor), intent(in)	g2_desc
	)

private

Init GRIB2.

Parameters

[in,out]	self	ip_mercator_grid object.
[in]	g2_desc	GRIB2 descriptor.

Author: Iredell

Date: 96-04-10

Definition at line 100 of file ip_mercator_grid_mod.F90.

◆ mercator_grid_area()

subroutine ip_mercator_grid_mod::mercator_grid_area	(	real, intent(in)	RLAT,
		real, intent(out)	AREA
	)

private

Grid box area for mercator cylindrical grids.

This subprogram computes the grid box area for a mercator cylindrical grid.

Program History Log

Date	Programmer	Comments
2015-01-21	gayno	initial version
2015-09-17	gayno	rename as "mercator_grid_area"

Parameters

[in]	rlat	latitude of grid point in degrees (real)
[out]	area	area weights in m**2 (real)

Author: Gayno

Date: 2015-01-21

Definition at line 387 of file ip_mercator_grid_mod.F90.

References dlon, dphi, and rerth.

Referenced by gdswzd_mercator().

◆ mercator_map_jacob()

subroutine ip_mercator_grid_mod::mercator_map_jacob	(	real, intent(in)	RLAT,
		real, intent(out)	XLON,
		real, intent(out)	XLAT,
		real, intent(out)	YLON,
		real, intent(out)	YLAT
	)

private

Map jacobians for mercator cylindrical grids.

This subprogram computes the map jacobians for a mercator cylindrical grid.

Program History Log

Date	Programmer	Comments
2015-01-21	gayno	initial version
2015-09-17	gayno	rename as "mercator_map_jacob"

Parameters

[in]	rlat	latitude in degrees (real)
[out]	xlon	dx/dlon in 1/degrees (real)
[out]	xlat	dx/dlat in 1/degrees (real)
[out]	ylon	dy/dlon in 1/degrees (real)
[out]	ylat	dy/dlat in 1/degrees (real)

Author: Gayno

Date: 2015-01-21

Definition at line 359 of file ip_mercator_grid_mod.F90.

References dlon, and dphi.

Referenced by gdswzd_mercator().

◆ mercator_vect_rot()

subroutine ip_mercator_grid_mod::mercator_vect_rot	(	real, intent(out)	CROT,
		real, intent(out)	SROT
	)

private

Vector rotation fields for mercator cylindrical grids.

This subprogram computes the vector rotation sines and cosines for a mercator cylindrical grid.

Program History Log

Date	Programmer	Comments
2015-01-21	gayno	initial version
2015-09-17	gayno	rename as "mercator_vect_rot".

Parameters

[in]	crot	clockwise vector rotation cosines (real)
[in]	srot	clockwise vector rotation sines (real) (ugrid=crotuearth-srotvearth; vgrid=srotuearth+crotvearth)

Author: Gayno

Date: 2015-01-21

Definition at line 331 of file ip_mercator_grid_mod.F90.

Referenced by gdswzd_mercator().

Variable Documentation

◆ dlon

real ip_mercator_grid_mod::dlon

private

Longitudinal direction grid length.

Definition at line 40 of file ip_mercator_grid_mod.F90.

Referenced by gdswzd_mercator(), mercator_grid_area(), and mercator_map_jacob().

◆ dphi

real ip_mercator_grid_mod::dphi

private

Latitudinal direction grid length.

Definition at line 41 of file ip_mercator_grid_mod.F90.

Referenced by gdswzd_mercator(), mercator_grid_area(), and mercator_map_jacob().

◆ rerth

real ip_mercator_grid_mod::rerth

private

Radius of the Earth.

Definition at line 42 of file ip_mercator_grid_mod.F90.

Referenced by gdswzd_mercator(), and mercator_grid_area().

Data Types

Functions/Subroutines

Variables

Detailed Description

Function/Subroutine Documentation

◆ gdswzd_mercator()

Program History Log

◆ init_grib1()

◆ init_grib2()

◆ mercator_grid_area()

Program History Log

◆ mercator_map_jacob()

Program History Log

◆ mercator_vect_rot()

Program History Log

Variable Documentation

◆ dlon

◆ dphi

◆ rerth