# Analysis-Ready Data (ARD)
For certain use cases, the readily available preprocessed data collections in the openEO back-ends are not sufficient or inappropriately preprocessed. openEO supports some processes to address very common preprocessing scenarios:
- Atmospheric correction of optical data
- SAR backscatter computation
These processes also offer a number of parameters to customize the processing. There are also variants with a default parametrization that results in data that is compliant with CEOS CARD4L specifications (opens new window).
We should note that these operations can be computationally expensive, so certainly affect overall processing time and cost of your final algorithm. Hence, make sure to make an informed decision when you decide to use these methods.