Matthijs Krijger - Academia.edu (original) (raw)

Papers by Matthijs Krijger

Atmospheric Measurement Techniques, Jul 20, 2020

Space Telescopes and Instrumentation 2022: Optical, Infrared, and Millimeter Wave

This is a copy of the published version, or version of record, available on the publisher's websi... more This is a copy of the published version, or version of record, available on the publisher's website. This version does not track changes, errata, or withdrawals on the publisher's site.

European Space Agency, Nov 30, 2020

Key Science Questions to be Addressed • What are the physical processes shaping planetary atmosph... more Key Science Questions to be Addressed • What are the physical processes shaping planetary atmospheres? • What are exoplanets made of? • How do planets and planetary systems form and evolve? Science Objectives (Chapter 2) Ariel Definition Study Report page 3 Foreword The concept of a mission devoted to atmospheric characterization of exoplanets through transit spectroscopy was first considered in Europe in 2007, shortly after the DARWIN proposal submitted to ESA for the first Cosmic Vision call for L-class missions was rejected because of the need for further scientific and technical developments. Following the decision, both ESA (EP-RAT panel report, October 2010) and the Exoplanetary Community (Blue Dot Team-Barcelona conference, September 2009) started a discussion to define a roadmap for exoplanetary research. Both groups concluded that an intermediate step was needed, both scientifically and technically, before the characterisation of Earth-like planets could be tackled, and recommended a transit spectroscopy mission as a first step to atmospheric characterisation. A short study was undertaken at ESTEC in the context of the ExoPlanet Roadmap Advisory Team mandate under the name ESM (Exoplanet Spectroscopy Mission). Following this study the Exoplanet Characterisation Observatory (EChO) was proposed and accepted for assessment phase study in the context of the ESA Cosmic Vision 2015-2025 programme M3 medium class mission opportunity. Although eventually not selected, the EChO study 1 allowed further development of the technical building blocks and the science case for an eventual transit spectroscopy mission. In response to the call for the next medium class opportunity, Cosmic Vision M4, a proposal was submitted in January 2015: the Atmospheric Remote-sensing InfraRed Large-survey (ARIEL). The mission was one of the three selected in June 2015 for study in a Phase 0/A, a competitive assessment phase 2. ARIEL was eventually selected as M4 in March 2018, and went into Phase B1, the definition study phase. The name of the mission has been changed to Ariel after selection. During Phase B1, the science case was studied in depth and consolidated under auspices of the Science Advisory Team, the bulk of the work being performed in a large number of science working groups in the Ariel Mission Consortium (AMC). The ESA Study Team and AMC reviewed the mission requirements, the technical design and analysis of the complete payload module (including telescope, instruments, guidance system and supporting infrastructure). The AMC developed an end-to-end performance simulator of the complete system. Two industrial contractors (Airbus Defence and Space, France and ThalesAlenia Space, France) reviewed the mission requirements, the technical design and analysis of the s/c and performed a programmatic analysis of the mission. Dedicated iterations were done in conjunction with both industrial and payload studies to harmonise the interfaces between the s/c and the payload, and to consolidate the payload accommodation. Recently the ESA Mission Adoption Review has successfully been concluded. This definition study report presents a summary of the very large body of work that has been undertaken on the Ariel mission over the 30-month period of the Ariel definition phase. As such, it represents the contributions of a large number of parties (ESA, industry, institutes and universities from 17 ESA member states, NASA CASE team), encompassing a very large number of people.

The SCIAMACHY instrument on-board ENVISAT measures since 2002 trace gas constituents of the atmos... more The SCIAMACHY instrument on-board ENVISAT measures since 2002 trace gas constituents of the atmosphere in nadir, limb and occultation configuration. It is an imaging spectrometer with q spectral range from the UV/VIS to SWIR (212 nm – 2384nm). In this paper we describe shortly the current status of the operational processing chains from Level 0-1b and Level 1b-2 that deliver

SCIAMACHY - Exploring the Changing Earth’s Atmosphere, 2010

ABSTRACT Spaceborne spectral measurements over long time periods require calibration and monitor-... more ABSTRACT Spaceborne spectral measurements over long time periods require calibration and monitor-ing of the instrument as a crucial prerequisite for successful retrieval of atmospheric parameters. Cali-bration applies a sequence of steps to the measurement data while monitoring assesses the optical per-formance thus permitting degradation corrections. The parameters characterising the instrument were obtained in a sequence of on-ground calibration runs under different environmental conditions. They are stored as Key Data and serve as input when deriving calibrated spectra. Relevant calibration steps include the memory effect and non-linearity, wavelength calibration and both spectral and spatial stray light corrections. Since SCIAMACHY is sensitive to the polarisation state of the incoming light, po-larisation needs to be thoroughly taken into account. The final step performs the radiometric calibra-tion. Once in orbit, the optical performance monitoring establishes information concerning the channel and wavelength dependent degradation. From the combination of the results for the different light paths, it is even possible to learn how individual optical components degrade.

This paper presents the main SECCHI CME list and the methodology behind its compilation. The list... more This paper presents the main SECCHI CME list and the methodology behind its compilation. The list is based on the COR2 observations to allow easy comparisons with the LASCO CME list based on the C2 and C3 coronagraphs. First, a separate CME list is constructed for each of the two STEREO spacecraft. The production of the catalog occurs in 3

identification of clouds and ice/snow Distinction between clouds and ice/snow covered surfaces in... more identification of clouds and ice/snow Distinction between clouds and ice/snow covered surfaces in the identification of cloud-free observations using SCIAMACHY PMDs

We report the COMPTEL detection of pulsed γ-emission from PSR B1509-58 up to at least 10 MeV usin... more We report the COMPTEL detection of pulsed γ-emission from PSR B1509-58 up to at least 10 MeV using data collected over more than 6 years. The 0.75-10 MeV lightcurve is broad and reaches its maximum near radio-phase 0.38, slightly beyond the maximum found at hard X-rays / soft γ-rays. In the 10-30 MeV energy range a strong source is present in the skymap positionally consistent with the pulsar, but we do not detect significant pulsed emission. However, the lightcurve is consistent with the pulse shape changing from a single broad pulse into a double-peak morphology. Our results significantly constrain pulsar modelling. KEYWORDS: gamma-rays; pulsars; PSR B1509-58; COMPTEL. 1.

A&A manuscript no. (will be inserted by hand later)

This paper discusses the basic concept of the calibration of the SCIAMACHY instrument and remaini... more This paper discusses the basic concept of the calibration of the SCIAMACHY instrument and remaining open issues. SCIAMACHY is a scanning Limb/Nadir spectrometer covering the wavelength range from 212 nm to 2386 nm. It was launched on-board ENVISAT in February 2002. In general the instrument performance is excellent: It performs as tested on ground and there is only very minor degradation in time. The only exception is the unexpected formation of water ice on the infrared channels 7 and 8 that attenuates the signal and a light leak in channel 7. Both effects will be discussed. In the paper we will explain all individual calibration steps needed to come to a wavelength calibrated spectrum of the Earth reflectance. Open points in the calibrations and latest improvements, such as the new radiometric calibration will also be treated.

Abstract. We report on the first firm detection of pulsed γ-ray emission from PSR B1509-58 in the... more Abstract. We report on the first firm detection of pulsed γ-ray emission from PSR B1509-58 in the 0.75–30 MeV energy range in CGRO COMPTEL data collected over more than 6 years. The modulation significance in the 0.75–30 MeV pulse-phase distribution is 5.4σ and the lightcurve is similar to the lightcurves found earlier between 0.7 and 700 keV: a single broad asymmetric pulse reaching its maximum 0.38 ± 0.03 in phase after the radio peak, compared to the offset of 0.30 found in the CGRO BATSE soft gamma-ray data, and 0.27 ± 0.01 for RXTE (2–16 keV), compatible with ASCA (0.7–2.2 keV). Analysis in narrower energy windows shows that the single broad pulse is significantly detected up to ∼ 10 MeV. Above 10 MeV we do detect marginally significant (2.1σ) modulation with an indication for the broad pulse. However, imaging analysis shows the presence of a strong 5.6σ source at the position

SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) was a scanning ... more SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) was a scanning nadir and limb spectrometer covering the wavelength range from 212 nm to 2386 nm in 8 channels. It is a joint project of Germany, the Netherlands and Belgium and was launched in February 2002 on the ESA's ENVISAT platform. After the platform failure in April 2012, the space agencies continue to support the operational product evolution in the frame of the SCIAMACHY Quality Working Group and Expert Support Laboratory. Note that SCIAMACHYs in-orbit lifetime was twice the planned lifetime. The instrument was designed to measure column densities and vertical profiles of trace gas species in the troposphere, in the stratosphere and in the mesosphere (Bovensmann et al., 1999). It can detect a wide range of trace gases and can provide information about aerosols and clouds. The operational processing of SCIAMACHY aims to deliver continuously high quality data products to the scientific commu...

QA4EO seeks to improve interoperability of Earth observations made by different instruments. This... more QA4EO seeks to improve interoperability of Earth observations made by different instruments. This is achieved through the establishment of the key principle that all data products should have associated with them a Quality indicator based on documented evidence of traceability to internationally agreed standards. QA4EO provides guidance on how best to follow and demonstrate this principle in a harmonious manner through a set of key guidelines. QA4EO makes clear that traceability for data products, starts with the on-ground calibration and goes up to derived products used in e.g. model and assimilation applications. The basis of all derived products are usually Level 1 data, which combine on-ground calibration with in-flight monitoring and calibration measurements. In the case of SCIAMACHY, the Level 1b data product comprises raw and geolocated data accompanied by all calibration parameters needed to generate the so-called Level 1c product with radiances as a function of wavelength. ...

Astronomy and Astrophysics, 1998

We report on the first firm detection of pulsed -ray emission from PSR B1509-58 in the 0.75-30 Me... more We report on the first firm detection of pulsed -ray emission from PSR B1509-58 in the 0.75-30 MeV energy range in CGRO COMPTEL data collected over more than 6 years. The modulation significance in the 0.75-30 MeV pulse-phase dis- tribution is 5:4 and the lightcurve is similar to the lightcurves found earlier between 0.7 and 700 keV: a single broad asym- metric pulse reaching its maximum 0.38 0.03 in phase af- ter the radio peak, compared to the offset of 0.30 found in the CGRO BATSE soft gamma-ray data, and 0.27 0.01 for RXTE (2-16 keV), compatible with ASCA (0.7-2.2 keV). Analysis in narrower energy windows shows that the single broad pulse is significantly detected up to 10 MeV. Above 10 MeV we do detect marginally significant (2:1) modulation with an indication for the broad pulse. However, imaging anal- ysis shows the presence of a strong 5.6 source at the position of the pulsar. To investigate this further, we have also analysed contemporaneous CGRO EGRET data (> 30 MeV) co...

Experimental Astronomy

The ground segment for the ESA M4 Ariel exoplanet space mission is introduced. The ground segment... more The ground segment for the ESA M4 Ariel exoplanet space mission is introduced. The ground segment encompasses the framework necessary to support the development of the Ariel mission to launch, in-flight operations and calibration, data processing pipeline and data handling, including user support. The structure of the ground segment and assumed responsibilities between ESA and the Ariel mission consortium is explained, along with their interfaces. The operational phases for the mission are introduced, including the early commissioning/verification phases, the science operations and the calibration strategy. The smooth transition of the ground segment through the various pre/post launch mission phases to nominal operations will be paramount in guaranteeing the success, scientific return and impact of the Ariel mission. The expected science data products are defined and a representative data processing pipeline is presented.

The goal of this study is to develop a method to quantify SCIAMACHY degradation and calibration i... more The goal of this study is to develop a method to quantify SCIAMACHY degradation and calibration in the UV, where the focus is on the O3 profile wavelength range 270-330 nm. Awaiting SCIAMACHY data reprocessing, the method has been performed on GOME observations, SCIAMACHY predecessor. The approach followed is to compare GOME reflectivity spectra with simulated spectra using collocated independent measurements of O3, temperature and pressure. For this a vector radiative transfer model (RTM) was used to avoid errors introduced by the GOME polarisation correction algorithm, (degradation of) the GOME polarisation measurements and errors in the forward radiances introduced when using a scalar RTM.

Since the launch in early 2002 SCIAMACHY has successfully operated in low-Earth orbit for more th... more Since the launch in early 2002 SCIAMACHY has successfully operated in low-Earth orbit for more than 8 years. For the first several months a challenging Commissioning Phase programme was executed. It successively brought SCIAMACHY into full operation mode and verified the instrument’s functional capabilities. In early August 2002 quasi-routine measurements executing nominal mission scenarios could start. In January 2003 the routine operations phase commenced. Since then SCIAMACHY is kept under strict configuration control. Because of the harsh space environment the instrument is subject to degradation, both optically and thermally. The optical performance is described by the throughput which is a measure for how optical components in a light path age with time. It also includes characterisation of optical imperfections such as scan angle dependence, channel 7 light leak and spatial stray light. Illustrating the thermal performance includes decontaminations, used to tackle the ice lay...

SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) was a scanning ... more SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) was a scanning nadir and limb spectrometer covering the wavelength range from 212 nm to 2386 nm in 8 channels. It is a joint project of Germany, the Netherlands and Belgium and was launched in February 2002 on the ESA's ENVISAT platform. After the platform failure in April 2012, the space Agencies continue to support the operational product evolution in the frame of the SCIAMACHY Quality Working Group and Expert Support Laboratory.. Note that SCIAMACHYs originally specified in-orbit lifetime was twice the planned lifetime. The instrument was designed to measure column densities and vertical profiles of trace gas species in the troposphere, in the stratosphere and in the mesosphere (Bovensmann et al., 1999). It can detect a wide range of trace gases and can provide information about aerosols and clouds. For the next Level 1 processor several improvements that concern the SWIR products CH4 and CO are...

Atmospheric Measurement Techniques, Jul 20, 2020

Space Telescopes and Instrumentation 2022: Optical, Infrared, and Millimeter Wave

This is a copy of the published version, or version of record, available on the publisher's websi... more This is a copy of the published version, or version of record, available on the publisher's website. This version does not track changes, errata, or withdrawals on the publisher's site.

European Space Agency, Nov 30, 2020

Key Science Questions to be Addressed • What are the physical processes shaping planetary atmosph... more Key Science Questions to be Addressed • What are the physical processes shaping planetary atmospheres? • What are exoplanets made of? • How do planets and planetary systems form and evolve? Science Objectives (Chapter 2) Ariel Definition Study Report page 3 Foreword The concept of a mission devoted to atmospheric characterization of exoplanets through transit spectroscopy was first considered in Europe in 2007, shortly after the DARWIN proposal submitted to ESA for the first Cosmic Vision call for L-class missions was rejected because of the need for further scientific and technical developments. Following the decision, both ESA (EP-RAT panel report, October 2010) and the Exoplanetary Community (Blue Dot Team-Barcelona conference, September 2009) started a discussion to define a roadmap for exoplanetary research. Both groups concluded that an intermediate step was needed, both scientifically and technically, before the characterisation of Earth-like planets could be tackled, and recommended a transit spectroscopy mission as a first step to atmospheric characterisation. A short study was undertaken at ESTEC in the context of the ExoPlanet Roadmap Advisory Team mandate under the name ESM (Exoplanet Spectroscopy Mission). Following this study the Exoplanet Characterisation Observatory (EChO) was proposed and accepted for assessment phase study in the context of the ESA Cosmic Vision 2015-2025 programme M3 medium class mission opportunity. Although eventually not selected, the EChO study 1 allowed further development of the technical building blocks and the science case for an eventual transit spectroscopy mission. In response to the call for the next medium class opportunity, Cosmic Vision M4, a proposal was submitted in January 2015: the Atmospheric Remote-sensing InfraRed Large-survey (ARIEL). The mission was one of the three selected in June 2015 for study in a Phase 0/A, a competitive assessment phase 2. ARIEL was eventually selected as M4 in March 2018, and went into Phase B1, the definition study phase. The name of the mission has been changed to Ariel after selection. During Phase B1, the science case was studied in depth and consolidated under auspices of the Science Advisory Team, the bulk of the work being performed in a large number of science working groups in the Ariel Mission Consortium (AMC). The ESA Study Team and AMC reviewed the mission requirements, the technical design and analysis of the complete payload module (including telescope, instruments, guidance system and supporting infrastructure). The AMC developed an end-to-end performance simulator of the complete system. Two industrial contractors (Airbus Defence and Space, France and ThalesAlenia Space, France) reviewed the mission requirements, the technical design and analysis of the s/c and performed a programmatic analysis of the mission. Dedicated iterations were done in conjunction with both industrial and payload studies to harmonise the interfaces between the s/c and the payload, and to consolidate the payload accommodation. Recently the ESA Mission Adoption Review has successfully been concluded. This definition study report presents a summary of the very large body of work that has been undertaken on the Ariel mission over the 30-month period of the Ariel definition phase. As such, it represents the contributions of a large number of parties (ESA, industry, institutes and universities from 17 ESA member states, NASA CASE team), encompassing a very large number of people.

The SCIAMACHY instrument on-board ENVISAT measures since 2002 trace gas constituents of the atmos... more The SCIAMACHY instrument on-board ENVISAT measures since 2002 trace gas constituents of the atmosphere in nadir, limb and occultation configuration. It is an imaging spectrometer with q spectral range from the UV/VIS to SWIR (212 nm – 2384nm). In this paper we describe shortly the current status of the operational processing chains from Level 0-1b and Level 1b-2 that deliver

SCIAMACHY - Exploring the Changing Earth’s Atmosphere, 2010

ABSTRACT Spaceborne spectral measurements over long time periods require calibration and monitor-... more ABSTRACT Spaceborne spectral measurements over long time periods require calibration and monitor-ing of the instrument as a crucial prerequisite for successful retrieval of atmospheric parameters. Cali-bration applies a sequence of steps to the measurement data while monitoring assesses the optical per-formance thus permitting degradation corrections. The parameters characterising the instrument were obtained in a sequence of on-ground calibration runs under different environmental conditions. They are stored as Key Data and serve as input when deriving calibrated spectra. Relevant calibration steps include the memory effect and non-linearity, wavelength calibration and both spectral and spatial stray light corrections. Since SCIAMACHY is sensitive to the polarisation state of the incoming light, po-larisation needs to be thoroughly taken into account. The final step performs the radiometric calibra-tion. Once in orbit, the optical performance monitoring establishes information concerning the channel and wavelength dependent degradation. From the combination of the results for the different light paths, it is even possible to learn how individual optical components degrade.

This paper presents the main SECCHI CME list and the methodology behind its compilation. The list... more This paper presents the main SECCHI CME list and the methodology behind its compilation. The list is based on the COR2 observations to allow easy comparisons with the LASCO CME list based on the C2 and C3 coronagraphs. First, a separate CME list is constructed for each of the two STEREO spacecraft. The production of the catalog occurs in 3

identification of clouds and ice/snow Distinction between clouds and ice/snow covered surfaces in... more identification of clouds and ice/snow Distinction between clouds and ice/snow covered surfaces in the identification of cloud-free observations using SCIAMACHY PMDs

We report the COMPTEL detection of pulsed γ-emission from PSR B1509-58 up to at least 10 MeV usin... more We report the COMPTEL detection of pulsed γ-emission from PSR B1509-58 up to at least 10 MeV using data collected over more than 6 years. The 0.75-10 MeV lightcurve is broad and reaches its maximum near radio-phase 0.38, slightly beyond the maximum found at hard X-rays / soft γ-rays. In the 10-30 MeV energy range a strong source is present in the skymap positionally consistent with the pulsar, but we do not detect significant pulsed emission. However, the lightcurve is consistent with the pulse shape changing from a single broad pulse into a double-peak morphology. Our results significantly constrain pulsar modelling. KEYWORDS: gamma-rays; pulsars; PSR B1509-58; COMPTEL. 1.

A&A manuscript no. (will be inserted by hand later)

This paper discusses the basic concept of the calibration of the SCIAMACHY instrument and remaini... more This paper discusses the basic concept of the calibration of the SCIAMACHY instrument and remaining open issues. SCIAMACHY is a scanning Limb/Nadir spectrometer covering the wavelength range from 212 nm to 2386 nm. It was launched on-board ENVISAT in February 2002. In general the instrument performance is excellent: It performs as tested on ground and there is only very minor degradation in time. The only exception is the unexpected formation of water ice on the infrared channels 7 and 8 that attenuates the signal and a light leak in channel 7. Both effects will be discussed. In the paper we will explain all individual calibration steps needed to come to a wavelength calibrated spectrum of the Earth reflectance. Open points in the calibrations and latest improvements, such as the new radiometric calibration will also be treated.

Abstract. We report on the first firm detection of pulsed γ-ray emission from PSR B1509-58 in the... more Abstract. We report on the first firm detection of pulsed γ-ray emission from PSR B1509-58 in the 0.75–30 MeV energy range in CGRO COMPTEL data collected over more than 6 years. The modulation significance in the 0.75–30 MeV pulse-phase distribution is 5.4σ and the lightcurve is similar to the lightcurves found earlier between 0.7 and 700 keV: a single broad asymmetric pulse reaching its maximum 0.38 ± 0.03 in phase after the radio peak, compared to the offset of 0.30 found in the CGRO BATSE soft gamma-ray data, and 0.27 ± 0.01 for RXTE (2–16 keV), compatible with ASCA (0.7–2.2 keV). Analysis in narrower energy windows shows that the single broad pulse is significantly detected up to ∼ 10 MeV. Above 10 MeV we do detect marginally significant (2.1σ) modulation with an indication for the broad pulse. However, imaging analysis shows the presence of a strong 5.6σ source at the position

SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) was a scanning ... more SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) was a scanning nadir and limb spectrometer covering the wavelength range from 212 nm to 2386 nm in 8 channels. It is a joint project of Germany, the Netherlands and Belgium and was launched in February 2002 on the ESA's ENVISAT platform. After the platform failure in April 2012, the space agencies continue to support the operational product evolution in the frame of the SCIAMACHY Quality Working Group and Expert Support Laboratory. Note that SCIAMACHYs in-orbit lifetime was twice the planned lifetime. The instrument was designed to measure column densities and vertical profiles of trace gas species in the troposphere, in the stratosphere and in the mesosphere (Bovensmann et al., 1999). It can detect a wide range of trace gases and can provide information about aerosols and clouds. The operational processing of SCIAMACHY aims to deliver continuously high quality data products to the scientific commu...

QA4EO seeks to improve interoperability of Earth observations made by different instruments. This... more QA4EO seeks to improve interoperability of Earth observations made by different instruments. This is achieved through the establishment of the key principle that all data products should have associated with them a Quality indicator based on documented evidence of traceability to internationally agreed standards. QA4EO provides guidance on how best to follow and demonstrate this principle in a harmonious manner through a set of key guidelines. QA4EO makes clear that traceability for data products, starts with the on-ground calibration and goes up to derived products used in e.g. model and assimilation applications. The basis of all derived products are usually Level 1 data, which combine on-ground calibration with in-flight monitoring and calibration measurements. In the case of SCIAMACHY, the Level 1b data product comprises raw and geolocated data accompanied by all calibration parameters needed to generate the so-called Level 1c product with radiances as a function of wavelength. ...

Astronomy and Astrophysics, 1998

We report on the first firm detection of pulsed -ray emission from PSR B1509-58 in the 0.75-30 Me... more We report on the first firm detection of pulsed -ray emission from PSR B1509-58 in the 0.75-30 MeV energy range in CGRO COMPTEL data collected over more than 6 years. The modulation significance in the 0.75-30 MeV pulse-phase dis- tribution is 5:4 and the lightcurve is similar to the lightcurves found earlier between 0.7 and 700 keV: a single broad asym- metric pulse reaching its maximum 0.38 0.03 in phase af- ter the radio peak, compared to the offset of 0.30 found in the CGRO BATSE soft gamma-ray data, and 0.27 0.01 for RXTE (2-16 keV), compatible with ASCA (0.7-2.2 keV). Analysis in narrower energy windows shows that the single broad pulse is significantly detected up to 10 MeV. Above 10 MeV we do detect marginally significant (2:1) modulation with an indication for the broad pulse. However, imaging anal- ysis shows the presence of a strong 5.6 source at the position of the pulsar. To investigate this further, we have also analysed contemporaneous CGRO EGRET data (> 30 MeV) co...

Experimental Astronomy

The ground segment for the ESA M4 Ariel exoplanet space mission is introduced. The ground segment... more The ground segment for the ESA M4 Ariel exoplanet space mission is introduced. The ground segment encompasses the framework necessary to support the development of the Ariel mission to launch, in-flight operations and calibration, data processing pipeline and data handling, including user support. The structure of the ground segment and assumed responsibilities between ESA and the Ariel mission consortium is explained, along with their interfaces. The operational phases for the mission are introduced, including the early commissioning/verification phases, the science operations and the calibration strategy. The smooth transition of the ground segment through the various pre/post launch mission phases to nominal operations will be paramount in guaranteeing the success, scientific return and impact of the Ariel mission. The expected science data products are defined and a representative data processing pipeline is presented.

The goal of this study is to develop a method to quantify SCIAMACHY degradation and calibration i... more The goal of this study is to develop a method to quantify SCIAMACHY degradation and calibration in the UV, where the focus is on the O3 profile wavelength range 270-330 nm. Awaiting SCIAMACHY data reprocessing, the method has been performed on GOME observations, SCIAMACHY predecessor. The approach followed is to compare GOME reflectivity spectra with simulated spectra using collocated independent measurements of O3, temperature and pressure. For this a vector radiative transfer model (RTM) was used to avoid errors introduced by the GOME polarisation correction algorithm, (degradation of) the GOME polarisation measurements and errors in the forward radiances introduced when using a scalar RTM.

Since the launch in early 2002 SCIAMACHY has successfully operated in low-Earth orbit for more th... more Since the launch in early 2002 SCIAMACHY has successfully operated in low-Earth orbit for more than 8 years. For the first several months a challenging Commissioning Phase programme was executed. It successively brought SCIAMACHY into full operation mode and verified the instrument’s functional capabilities. In early August 2002 quasi-routine measurements executing nominal mission scenarios could start. In January 2003 the routine operations phase commenced. Since then SCIAMACHY is kept under strict configuration control. Because of the harsh space environment the instrument is subject to degradation, both optically and thermally. The optical performance is described by the throughput which is a measure for how optical components in a light path age with time. It also includes characterisation of optical imperfections such as scan angle dependence, channel 7 light leak and spatial stray light. Illustrating the thermal performance includes decontaminations, used to tackle the ice lay...

SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) was a scanning ... more SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) was a scanning nadir and limb spectrometer covering the wavelength range from 212 nm to 2386 nm in 8 channels. It is a joint project of Germany, the Netherlands and Belgium and was launched in February 2002 on the ESA's ENVISAT platform. After the platform failure in April 2012, the space Agencies continue to support the operational product evolution in the frame of the SCIAMACHY Quality Working Group and Expert Support Laboratory.. Note that SCIAMACHYs originally specified in-orbit lifetime was twice the planned lifetime. The instrument was designed to measure column densities and vertical profiles of trace gas species in the troposphere, in the stratosphere and in the mesosphere (Bovensmann et al., 1999). It can detect a wide range of trace gases and can provide information about aerosols and clouds. For the next Level 1 processor several improvements that concern the SWIR products CH4 and CO are...