Skip to content

preprocessing

Jump to bottom
gwbres edited this page Aug 24, 2024 · 11 revisions

Preprocessing toolkit

rinex-cli integrates a Filter designer (or Preprocessor) that you can invoke with -P.
It is very similar to glab (ESA toolkit).

-P is very important, it allows focusing (pruning) the dataset prior running an operation. For example, this is how we select candidate vehicles to the navigation process or Constellation systems to work with. Applying efficient -P options will also improve your solutions, for example if you get rid of less performant constellations, signals or vehicles.

Behavior

To describe several preprocessing operation, you can either

  • invoke -P as many times as you need
  • or use the ; separator, in a single -P

For example, these are two valid methods to reduce a time frame of Galileo vehicles:

rinex-cli -P "Gal;<= 2024-08-24T10:00:00 UTC" [...]
rinex-cli -P Gal -P "<= 2024-08-24T10:00:00 UTC" [...]

Note that description that require operands or whitespaces need to be wrapped in inverted commas.

  • Faulty description only results in a warning trace, it will not cause the application to crash. The operation is just discarded and the logs will let you know. -P operations will heavily impact your solutions and the generated reports, it is very important to check that the operations did apply like you intended: check the logs!

  • Currently, operations apply to the entire context. For example when you select a constellation, it will apply to every single input product.

Operands

Most filter operation support an Operand. When it is omitted, the Equality operand (=) is implied.

  • < Lower Than
  • <= Lower Than or Equals
  • > Greater Than
  • >= Greater Than or Equals
  • = Equality
  • != Inequality

Case sensitivity

The filter design is case insensitive and is very flexible in your operation description. For example, these are all valid Galileo selection methods:

  • -P Gal
  • -P gal
  • -P galileo

Whitespace tolerance

The filter designer is very tolerant to whitespaces. We tolerate missing whitespace between Operands and Operations:

rinex-cli -P "Gal;<2024-08-24T10:00:00 UTC" [...]

Tutorials

Refer to the tutorials/ folder for example of applications. All our demos use the filter designer extensively.
Do not hesitate to customize the examples as you will, for example to focus the timeframe or select different constellations and signals!

Next step

Clone this wiki locally