The GOMOS Cal/Val Plan addressed Cal/Val activities undertaken to ensure the generation of high quality products and definitive validation of the products after launch.

Download the GOMOS Calibration and Algorithms Verification Plan for more detail.

Typical Routine Calibration sequence

Seven consecutive orbits per month were acquired with the GOMOS instrument in different monitoring modes:

• One orbit in SSM mode. The brightest stars had to be chosen (this could not be done automatically by Starsel). At least six stars in dark limb (including at least three in eclipse) and three stars in bright limb.
   
• Two orbits in UNI mode, one at 10 km and one at 30 km altitude. The start times and the durations were always the same. The integration time was 0.5 s except for the last observation of the orbit. The azimuth was always equal to 30°. The location of the SATU windows ws always the same.
   
• Two orbits in LIN mode, from 300 to 100 km altitude. The brightest stars had to be chosen (this cannot be done automatically by Starsel). At least six stars in dark limb (including at least three in eclipse) and three stars in bright limb. The integration time was 0.25 s for the first orbit and 0.5 s for the second one.
   
• Two orbits in OCC with as much Dark Sky Area (DSA) acquisitions as possible. The altitude range was 300 to 200 km for the first orbit and 300 to 0 km for the last orbit.

Due to different needs, this sequence changed during the mission.

Download the Envisat Phase E Cal/Val Acquisition Plan for more detail.

The validation report summarises all validation results of the last GOMOS ESA operational datasets.

GOMOS Validation and Verification Documents:

• Validation Report: D. Hubert et al., "Multi-TASTE Phase F Final Report / October 2013 - December 2015", Report of the Multi-TASTE project, TN-BIRA-IASB-MultiTASTE-Phase-F-FR issue 2 revision A, 1 February 2016
• Final validation report: A. Van Gisel, P. Stammes, and A. Piters, 2013: Final report of the VALID-2 project
• Preliminary validation report: Van Gisel, 2012: Validation of GOMOS version 6.01 ozone profiles using ground-based lidar observations

• Verification reports:
  • Comparison of GOMOS Prototype Processor Versions 6cf and 7de
  • Ground-based Network Verification of Gomos Ozone Profile data v 7.0cd versus v 6.0cf
  • Impact of the Implementation of the Full Covariance Matrix Approach on Some Level 2 Products - version 1.1
  • Comparison of HRTP Profiles from GOPR versions7.0ab and 6.0cf
  • Statistical comparison of vertical profiles of local density and aerosol extinction coefficient from testing datasets processed with GOPR6.0cf and GOPR7.0ab, v10
  • Quality of O2 vertical profiles