The Community Doppler Lidar Simulation Model (DLSM)

Horizontal Wind Model Errors

The Horizontal Wind Models provide sampling accuracy, error biases and representativeness errors depending upon which horizontal wind model (High Resolution model, Grid Area - MPA, Grid Area - Least Squares) is used. Each error type is identified with indicators for error, data level, error type and error attribute.

ERROR DEFINITION

The data level corresponds to a specific LSM Level product. The error levels are defined as follows...

DATA LEVEL

00 - error with respect to analog/digitization

01 - error with respect to Line of sight velocities

2A - error with respect to Grid area winds

2B - error with respect to High Resolution winds

03 - error with respect to Model/other assisted winds.

ERROR TYPE

0 - estimation with respect to the actual winds at the shot locations

1 - estimation with respect to the actual winds as the assigned location

2 - estimation with respect to the subgrid averaged winds.

ERROR ATTRIBUTE

E - actual average error

R - weighted root mean square error or goodness of fit

B - weighted bias.

For example, take E 2B 0 E,

where

E - error indicator

2B - data level

0 - data level

E - error attribute

HORIZONTAL WIND MODEL ERRORS

High Resolution mode

E2BOE = Ve(m)i - Va(a:f)i

E2BOB = E2BOE

E2BOR = 0.0

E2B1E = Ve(m)i - Va(m)i

E2B1B = E2B1E

E2B1R = 0

Grid Area Resolution mode (MPA)

E2AOE = ( SiN (Ve(m)i × wf(i)) / SiNwf(i) ) - ( SiNVa(a:f)i ) / N

E2AOB = ( SiN (Ve(m)i - Va(a:f)i) × wf(i) ) / SiN wf(i)

E2AOR = Ö(( SiN (Ve(m)i - Va(a:f)i)2 × wf(i) ) / SiN wf(i) )

E2A1E = ( SiN Ve(m)i × wf(i) ) / SiN wf(i) - ( SiN Va(m)i ) / N

E2A1B = ( SiN (Ve(m)i - Va(m)i) × wf(i) ) / SiN wf(i)

E2A1R = Ö (( SiN (Ve(m)i - Va(m)i)2 × wf(i) ) / SiN wf(i) )

E2A2E = ( SiN Ve(m)i × wf(i) ) / SiN wf(i) - Vg

E2A2B = ( SiN (Ve(m)i - Vg) × wf(i) ) / SiN wf(i)

E2A2R = Ö (( SiN (Ve(m)i - Vg)2 × wf(i) ) / SiN wf(i) )

Grid Area Resolution mode (Least Squares)

E2A0E = VeLS - SiN Va(a:f)i/N

E2AOR = X2

E2A2E = VeLS - Vg

where

N - represents the number of shots

Va(a:f)i - represents the average error of the actual winds at the for the i'th pair

Ve(m)i - represents the estimated velocity at the weighted measurement location for the i'th pair

Va(m)i - represents the actual wind velocity at the weighted measurement location for the i'th pair

Vg - represents the average of all winds within the global grid domain

VeLS - represents the least squares velocity

 


© Copyright 1995-2005, Simpson Weather Associates, Inc.

Last Updated: 02/07/2007