Journal cover Journal topic
Atmospheric Measurement Techniques An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 3.400 IF 3.400
  • IF 5-year value: 3.841 IF 5-year
    3.841
  • CiteScore value: 3.71 CiteScore
    3.71
  • SNIP value: 1.472 SNIP 1.472
  • IPP value: 3.57 IPP 3.57
  • SJR value: 1.770 SJR 1.770
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 70 Scimago H
    index 70
  • h5-index value: 49 h5-index 49
Discussion papers
https://doi.org/10.5194/amt-2019-433
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/amt-2019-433
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.

Submitted as: research article 11 Dec 2019

Submitted as: research article | 11 Dec 2019

Review status
This preprint is currently under review for the journal AMT.

Optimised degradation correction for SCIAMACHY satellite solar measurements from 330 to 1600 nm by using its internal white light source

Tina Hilbig1, Klaus Bramstedt1, Mark Weber1, John P. Burrows1, and Matthijs Krijger2 Tina Hilbig et al.
  • 1Institute of Environmental Physics, University of Bremen, Bremen, Germany
  • 2Earth Space Solutions, Utrecht, the Netherlands

Abstract. SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) on-board the European Environmental Satellite (Envisat) provided spectrally resolved measurements in the wavelength range from 0.24 to 2.4 μm by looking into the Earth’s atmosphere using different viewing geometries (limb, nadir, solar and lunar occultation). These observations were used to derive a multitude of parameters, in particular atmospheric trace gas amounts. In addition to radiance measurements solar spectral irradiances (SSI) were measured on a daily basis. The instrument was operating for nearly a decade, from August 2002 to April 2012. Due to the harsh space environment, it suffered from continuous optical degradation. As part of recent radiometric calibration activities an optical (physical) model was introduced that describes the behaviour of the scanner unit of SCIAMACHY with time (Krijger et al., 2014). This model approach accounts for optical degradation by assuming contamination layers on optical surfaces in the scanner unit. The variation of layer thicknesses of the various optical components is determined from the combination of solar measurements from different monitoring light paths available for SCIAMACHY. In this paper, we present an optimisation of this degradation correction approach, which in particular improves the solar spectral data. An essential part of the modification is the use of measurements from SCIAMACHY’s internal white light source (WLS) in combination with direct solar measurements. The WLS, as an independent light source, gives, therefore, an opportunity to better separate instrument variations and natural solar variability. However, the WLS emission depends on its burning time and is changing with time as well. To use these measurements in the optimised degradation correction, the change of the WLS emission in space needs to be characterised first. The changes of the WLS with accumulated burning time are in good agreement with detailed laboratory lamp studies by Sperling et al. (1996). Although the optimised degradation corrected SCIAMACHY SSI show still some instrumental issues when compared to SSI measurements from other instruments and model reconstructions, our study demonstrates the potential for the use of an internal WLS for degradation monitoring.

Tina Hilbig et al.

Interactive discussion

Status: final response (author comments only)
Status: final response (author comments only)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment

Tina Hilbig et al.

Tina Hilbig et al.

Viewed

Total article views: 163 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
131 30 2 163 4 0
  • HTML: 131
  • PDF: 30
  • XML: 2
  • Total: 163
  • BibTeX: 4
  • EndNote: 0
Views and downloads (calculated since 11 Dec 2019)
Cumulative views and downloads (calculated since 11 Dec 2019)

Viewed (geographical distribution)

Total article views: 112 (including HTML, PDF, and XML) Thereof 112 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 

Cited

Saved

No saved metrics found.

Discussed

No discussed metrics found.
Latest update: 22 Feb 2020
Publications Copernicus
Download
Short summary
One of the main limitations for long-term space-based measurements is the optical degradation of the instrument. We present an optimisation of the degradation correction approach (Krijger et al., 2014) for the SCIAMACHY satellite, which in particular improves the solar spectral data. The main achievement of this study was the successful description of the ageing of SCIAMACHY’s internal white light source and its integration in the existing degradation model.
One of the main limitations for long-term space-based measurements is the optical degradation of...
Citation