====== QC2d-4 Statistics control Accumulation Method ======


==== Description of Method ==== 

The monthly accumulated precipitation RRM is calculated.
The corresponding normal monthly accumulated precipitation RRM' is retrieved form the climate data base.

Corresponding accumulated value at three neighbour stations are RRMn1, RRMn2, RRMn3. Corresponding reference accumulated value at three neighbour stations are RRMn'1, RRMn'2, RRMn'3. 

An error is detected when

<nowiki>| RRM - RRM' | > tol1</nowiki>

and at least two of the three following inequalities are satisfied

<nowiki>| RRMn1 - RRMn'1 | < tol1</nowiki>

<nowiki>| RRMn2 - RRMn'2 | < tol1</nowiki>

<nowiki>| RRMn3 - RRMn'3 | < tol1</nowiki>

where tol1 is a tolerance value.

==== Quality Control Level ====

  * QC2d-4


==== Run Parameters ====

It shall be possible to run the algorithm for

  * RR_1
  * RR_6
  * RR_12
  * RR_24

==== Characteristics of the data to which the method is applied ====

__CONTROLINFO AND/OR USEINFO__

  * none
 
__TYPEID, PARAMIDS, OTHER METADATA__

  * all typeid

==== Flag Settings ====

__SPECIFICATION OF CONTROLFLAGS TO BE SET FOR EXPECTED RESULTS OF THE ALGORITHM, I.E. CONSIDER BOTH POSITIVE AND NEGATIVE RESULTS__

  * fstat = 1 on no error detection
  * fstat = 2 on error detection


__EXPECTIONS OF THE USEINFO FLAGS CORRESPONDING TO CONTROLINFO FLAG SETTINGS__

  * fstat = 2 -> controlinfo(2) = 2


==== Dependencies ====

  * Definition of neighbour station
  * Definition of regions and related region reference station
  * Extracts from KDVH