Definition of a Processing Unit

Each request is "worth" a proportional amount of processing unit(s) depending on what data and processing is requested. We define one processing unit (PU) as a request for:

  • an output (image) size of 512 x 512 pixels,
  • 3 collection input bands,
  • one data sample per pixel (see sample),
  • an output (image) format not exceeding 16 bits per pixel,
  • without additional processing (e.g. orthorectification) applied,
  • the request is processed on-the-fly (i.e. process API, WMS, WMTS, WCS or FIS request).

In addition to this:

  • The minimal weight for a request is 0.001 PU.
  • The number of remaining processing units is reduced only when a request successfully executes, i.e. when the response code is 2XX.

We use "multiplication factors" to calculate how many processing units are required for each request. The definition of 1 processing unit and the calculation rules are summarized in the table:

Parameter/APIQuantity for 1 PURules for multiplication factors
Output size (width x height)512 x 512 pxThe multiplication factor is calculated by dividing requested output (image) size (width x height) by 512 x 512.

The minimum value of this multiplication factor is 0.01. This corresponds to an area of 0.25 km2 for Sentinel-2 data at 10 m spatial resolution.
Number of input bands3The multiplication factor is calculated by dividing the requested number of input bands by 3.

An exception is requesting dataMask which is not counted.
Output format8 bit or 16 bit
TIFF/JPG/PNG
Requesting 32 bit float TIFF will result in a multiplication factor of 2 due to larger memory consumption and data traffic.

Requesting application/octet-stream will result in a multiplication factor of 1.4 due to additional integration costs (This is used for integration with external tools such as xcube.).
Number of data samples1The multiplication factor equals the number of data samples per pixel.
OrthorectificationNoRequesting orthorectification (for S1 GRD data) will result in a multiplication factor of 2 due to additional processing requirements (This rule is not applied at the moment.).
Batch ProcessingNoProcessing with batch processing API will result in a multiplication factor of 1/3.
Thus, three times more data can be processed comparing to process API for the same amount of PUs.

Request weight calculation examples

Sentinel-1 change detection

An example of the calculation of processing units for a Sentinel-1 change detection request (e.g. comparison of two time slices) is presented in the table below.

ParameterQuantityMultiplication factorDetails
Output size (width x height)1024 x 1024 pxx 4The requested output size is 1024 x 1024 px which is 4 times larger than the output size for one PU (512 x 512 px). Hence the multiplication factor is 4.
Number of input bands4x 4/34 input bands are requested, which is 4/3 times more than 3 input bands, which are included in one PU. The multiplication factor is thus 4/3.
Output format32-bit floatx 2The requested 32 bit float TIFF has a multiplication factor of 2.
Number of data samples2x 22 data samples (one for each time slice) were requested for each pixels. Thus the multiplication factor is 2.
OrthorectificationYesx 2Ortorectification is requested, which results in a multiplication factor of 2.
Total42.667 processing unitsTo calculate the number of processing units for this request multiply all the individual multiplication factors:
4 x 4/3 x 2 x 2 x 2 = 42.667

Note: Statistical API (FIS requests) is also a multi-temporal request. The same rules for calculating multiplication factors apply.

NDVI calculation for a parcel

An example of the calculation of processing units for the NDVI value over a 4 hectare large parcel at 10 m spatial resolution is presented in the table below.

ParameterQuantityMultiplication factorDetails
Output size (width x height)20 x 20 pxx 0.01The requested output size is 20 x 20 px which is smaller than the minimum area, thus the multiplication factor is 0.01.
Number of input bands2x 2/32 input bands are requested, thus the multiplication factor is 2/3.
Output format16-bit tiffx 1The same as in the definition of one processing unit, thus the multiplication factor is 1.
Number of data samples1x 1The same as in the definition of one processing unit, thus the multiplication factor is 1.
OrthorectificationNox 1The same as in the definition of one processing unit, thus the multiplication factor is 1.
Total0.0067 processing unitsTo calculate the number of processing units for this request multiply all the individual multiplication factors:
0.01 x 2/3 x 1 x 1 = 0.0067