Upkeep - Categorization

From Wikicap - European Commission



The anomaly detection processes frequently relies on aerial or VHR orthoimagery.

It's not straightforward to specify the usability of imagery in temporal terms (expressed as a maximum age) for all applications and uses. However, depending on the particular application three groups of requirements can be defined:

  • For the systematic review cycle leading to application of art 31a (thread 3b) or a refresh project (thread 3e), the system's imagery should support retroactive recovery up to three years. In other words for any year N, image acquisition dates shall never precede January 1, N-3.
  • It should not take more than 3 months to process raw image captures (the flight) into an orthoimage product, regardless whether the processing is done in house, by a contractor or by a government partner.
In cases where that processing takes longer (i.e. the three months passed over), the processed imagery shall still be made available to support the following farmer's aid application and other IACS operations. In short, it has to be available by the time the pre-established form is produced.
  • Upon receipt, the orthoimagery should be immediately made available to all farmers, inspectors and other personnel, even for zones not yet processed in the refresh cycle or project.


A number of reported anomalies are based on other data sources, not on imagery. They may carry attributes values of the reference parcel with or without geospatial component:

  • An OTSC inspector can provide a valid reference area value.
  • A part of the boundary can originate from topographic surveys.
  • An appropriate "as built" plan can be delivered from a third party partner.

Depending on the particular conditions, data from non-image sources might be more appropriate than the image. This is especially justified when such data is more current than imagery.

Assessment of data sources

It is obvious that addressing a non-conformity can only be based on data that are both current and suitable. Indeed, it makes little sense to process a reference parcel according to a situation that no longer matches reality. Neither does it make sense to process a change that is only half covered by the image. Therefore, the workflow involves assessing usability in terms of suitability and relevance of source data. The diagram bellow can be split in two phases:

  • Phase 1(upper part of diagram) dealing with:
    • data availability
    • data usability
  • Phase 2(lower part of diagram)
    • categorization of suitable data (single or in combination)

BP0106001 Assess potential data sources.png

figure 3b.1: Activity diagram to assess suitability of data sources for upkeep

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