Analysis Steps#

The analysis of CTAO data in ctapipe follows a staged approach, moving from raw data to high-level reconstructed parameters.

Data Levels#

  • R1: Calibrated waveforms (photo-electrons).

  • DL0: Reduced data (e.g. after volume reduction).

  • DL1: Integrated camera images and timing information (image parameters).

  • DL2: Reconstructed event parameters (energy, direction, particle type).

Regarding the data format for each level, please refer to the Data Format section of the user guide.

Processing Pipeline#

  1. Calibration: Converts raw ADC counts to photo-electrons.

  2. Image Extraction: Integrates waveforms to produce 2D camera images (DL1a).

  3. Image Cleaning: Removes noise pixels, leaving only the Cherenkov shower signal.

  4. Parameterization: Calculates Hillas and timing parameters from the cleaned image (DL1b).

  5. Reconstruction:

    • Direction: Uses multiple telescope views (stereo) to find the source position.

    • Energy: Estimates the primary particle’s energy.

    • Classification: Distinguishes between gamma-rays and hadronic background.