Parameterize the observation error as a series of steps with linear interpolation between each step. More...

#include <ObsErrorModelStepwiseLinear.h>

Inheritance diagram for ufo::ObsErrorModelStepwiseLinear:

Collaboration diagram for ufo::ObsErrorModelStepwiseLinear:

[legend]

Public Member Functions
	ObsErrorModelStepwiseLinear (const eckit::LocalConfiguration)

	~ObsErrorModelStepwiseLinear ()

void	compute (const ObsFilterData &, ioda::ObsDataVector< float > &) const
	compute the result of the function More...

const ufo::Variables &	requiredVariables () const
	geovals required to compute the function More...

Public Member Functions inherited from ufo::ObsFunctionBase< float >
	ObsFunctionBase (const eckit::LocalConfiguration conf=eckit::LocalConfiguration())

virtual	~ObsFunctionBase ()

Static Public Member Functions
static const std::string	classname ()

Private Attributes
ufo::Variables	invars_

ObsErrorModelStepwiseLinearParameters	options_

bool	isAscending_ = true

bool	multiplicative_ = false

Additional Inherited Members
Public Types inherited from ufo::ObsFunctionBase< float >
typedef float	Value_
	Type of the values produced by the function. More...

Detailed Description

Parameterize the observation error as a series of steps with linear interpolation between each step.

This routine was designed to mimic the GSI fix-file of prepobs_errtable.txt Input is a vector of x-values (e.g. pressures) and corresponding vector of obserrors. Interpolation in X-coordinate requires the value of X for which the output, Y, is calculated using linear interp of obserrors between the steps. If the optional "scale_factor_var" exists, then the final output obserr is calculated as a result of linear interpolation of errors times the scale_factor_var. An example of such usage is RH obserror values between zero and one multiplied by specific_humidity@ObsValue for final ObsError.

        + err_n                             o
        |                                /
        |                             /
        + err_n-1                  o
        |                       /
obserr  +                     *
        |                  /
        |               /
   err2 +            o
        |          /
        |       /
   err1 +     o
        |  /
   err0 +-----+------+---------*---+--------+
        p_0, p_1,   p_2,...   p*  p_n-1,   p_n

example configurations for a FilterBase derived class:

- Filter: {Filter Name}

Example for air temperature assigned obserror by pressure (e.g., sonde data)

  filter variables:
  - name: air_temperature
  action:
    name: assign error
    error function:
      name: ObsErrorModelStepwiseLinear@ObsFunction
      options:
        xvar:
          name: air_pressure@ObsValue
        xvals: [110000, 85000, 50000, 25000, 10000, 1]   #Pressure (Pa)
        errors: [1.1, 1.3, 1.8, 2.4, 4.0, 4.5]

Definition at line 94 of file ObsErrorModelStepwiseLinear.h.