ATmospheric LIDar (ATLID): Pre-Launch Testing and Calibration of the European Space Agency Instrument That Will Measure Aerosols and Thin Clouds in the Atmosphere

ATLID (ATmospheric LIDar) is the atmospheric backscatter Light Detection and Ranging (LIDAR) instrument on board of the Earth Cloud, Aerosol and Radiation Explorer (EarthCARE) mission, the sixth Earth Explorer Mission of the European Space Agency (ESA) Living Planet Programme. ATLID’s purpose is to provide vertical profiles of optically thin cloud and aerosol layers, as well as the altitude of cloud boundaries, with a resolution of 100 m for altitudes of 0 to 20 km, and a resolution of 500 m for 20 km to 40 km. In order to achieve this objective ATLID emits short duration laser pulses in the ultraviolet, at a repetition rate of 51 Hz, while pointing in a near nadir direction along track of the satellite trajectory. The atmospheric backscatter signal is then collected by its 620 mm aperture telescope, filtered through the optics of the instrument focal plane assembly, in order to separate and measure the atmospheric Mie and Rayleigh scattering signals. With the completion of the full instrument assembly in 2019, ATLID has been subjected to an ambient performance test campaign, followed by a successful environmental qualification test campaign, including performance calibration and characterization in thermal vacuum conditions. In this paper the design and operational principle of ATLID is recalled and the major performance test results are presented, addressing the main key receiver and emitter characteristics. Finally, the estimated instrument, in-orbit, flight predictions are presented; these indicate compliance of the ALTID instrument performance against its specification and that it will meet its mission science objectives for the EarthCARE mission, to be launched in 2023.

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ATmospheric LIDar (ATLID): European Space Agency Instrument Ready to Measure Aerosols and Thin Clouds in Atmosphere

10.20944/preprints202012.0333.v1 ◽

2020 ◽

Author(s):

João Pereira do Carmo ◽

Geraud de Villele ◽

Kotska Wallace ◽

Alain Lefebvre ◽

Kaustav Ghose ◽

...

Keyword(s):

Rayleigh Scattering ◽

Performance Test ◽

European Space Agency ◽

Laser Pulses ◽

Backscatter Signal ◽

Space Agency ◽

Explorer Mission ◽

Thin Cloud ◽

Atmospheric Backscatter ◽

Along Track

ATLID (ATmospheric LIDar) is the atmospheric backscatter LIDAR (Light Detection and Ranging) on board of the EarthCARE (Earth Cloud, Aerosol and Radiation Explorer) mission, the sixth Earth Explorer Mission of the ESA (European Space Agency) Living Planet Programme [1-5]. ATLID’s purpose is to provide vertical profiles of optically thin cloud and aerosol layers, as well as the altitude of cloud boundaries [6-10]. In order to achieve this objective ATLID emits short duration laser pulses in the UV, at a repetition rate of 51 Hz, while pointing in a near nadir direction along track of the satellite trajectory. The atmospheric backscatter signal is then collected by its 620 mm aperture telescope, filtered through the optics of the instrument focal plane assembly, in order to separate and measure the atmospheric Mie and Rayleigh scattering signals. With the completion of the full instrument assembly in 2019, ATLID has been subjected to an ambient performance test campaign, followed by a successful environmental qualification test campaign, including performance calibration and characterization in thermal vacuum conditions. In this paper the design and operational principle of ATLID is recalled and the major performance test results are presented, addressing the main key receiver and emitter characteristics. Finally, the estimated instrument, in-orbit, flight predictions are presented; these indicate compliance of the ALTID instrument performance against its specification and that it will meet its mission science objectives for the EarthCARE mission, to be launched in 2023.

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The European Space Agency’s Earth Explorer Mission CryoSat: measuring variability in the cryosphere

Annals of Glaciology ◽

10.3189/172756404781814663 ◽

2004 ◽

Vol 39 ◽

pp. 313-320 ◽

Cited By ~ 33

Author(s):

Mark R. Drinkwater ◽

Richard Francis ◽

Guy Ratier ◽

Duncan J. Wingham

Keyword(s):

European Space Agency ◽

Ice Sheets ◽

Arctic Sea Ice ◽

The Arctic ◽

Radar Altimeter ◽

Operating Characteristics ◽

Space Agency ◽

Explorer Mission ◽

Arctic Sea ◽

Ku Band

AbstractCryoSat is currently being prepared for a 2005 launch as the first European Space Agency Earth Explorer Opportunity mission. It is a dedicated cryospheric mission equipped with a Ku-band SIRAL (SAR/Interferometric Radar ALtimeter), whose primary objectives are to measure the variability and trends in the mass of the Arctic sea-ice cover and large terrestrial ice sheets. In this paper, an overview is provided of the mission and of the measurement characteristics of the new SIRAL instrument. Examples of data acquired on recent preparatory campaigns are presented, illustrating the operating characteristics of the key SIRAL modes. Preparatory plans for calibration and validation of CryoSat data are described.

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Retrieval of atmospheric backscatter and extinction profiles with the aladin airborne demonstrator (A2D)

EPJ Web of Conferences ◽

10.1051/epjconf/201817602021 ◽

2018 ◽

Vol 176 ◽

pp. 02021 ◽

Cited By ~ 1

Author(s):

Alexander Geiss ◽

Uwe Marksteiner ◽

Oliver Lux ◽

Christian Lemmerz ◽

Oliver Reitebuch ◽

...

Keyword(s):

Direct Detection ◽

European Space Agency ◽

Backscatter Coefficient ◽

Detection Scheme ◽

Space Agency ◽

Fabry Perot ◽

Lidar Ratio ◽

Wind Lidar ◽

Wind Retrievals ◽

Atmospheric Backscatter

By the end of 2017, the European Space Agency (ESA) will launch the Atmospheric laser Doppler instrument (ALADIN), a direct detection Doppler wind lidar operating at 355 nm. An important tool for the validation and optimization of ALADIN’s hardware and data processors for wind retrievals with real atmospheric signals is the ALADIN airborne demonstrator A2D. In order to be able to validate and test aerosol retrieval algorithms from ALADIN, an algorithm for the retrieval of atmospheric backscatter and extinction profiles from A2D is necessary. The A2D is utilizing a direct detection scheme by using a dual Fabry-Pérot interferometer to measure molecular Rayleigh signals and a Fizeau interferometer to measure aerosol Mie returns. Signals are captured by accumulation charge coupled devices (ACCD). These specifications make different steps in the signal preprocessing necessary. In this paper, the required steps to retrieve aerosol optical products, i. e. particle backscatter coefficient βp, particle extinction coefficient αp and lidar ratio Sp from A2D raw signals are described.

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Aeolus: ESA’s wind mission. Status and future challenges

10.5194/egusphere-egu21-1676 ◽

2021 ◽

Author(s):

Tommaso Parrinello ◽

Anne Grete Straume ◽

Jonas Von Bismark ◽

Sebastian Bley ◽

Viet Duc Tran ◽

...

Keyword(s):

World Wide ◽

Positive Impact ◽

European Space Agency ◽

Weather Forecast ◽

Horizontal Line ◽

Space Agency ◽

Future Challenges ◽

The Status ◽

Other World ◽

Atmospheric Backscatter

The European Space Agency (ESA)&#8217;s wind mission, Aeolus, was launched on 22 August 2018. It is a member of the ESA Earth Explorer family and its main objective is to demonstrate the potential of Doppler wind Lidars in space for improving weather forecast and to understand the role of atmospheric dynamics in climate variability. Aeolus carries a single instrument called ALADIN: a high sophisticated spectral resolution Doppler wind Lidar which operates at 355 which is the first of its kind to be flown in space.Aeolus provides profiles of single horizontal line-of-sight winds (primary product) in near-real-time (NRT), and profiles of atmospheric backscatter and extinction. The instrument samples the atmosphere from about 30 km down to the Earth&#8217;s surface, or down to optically thick clouds. The required precision of the wind observations is 1-2.5 m/s in the troposphere and 3-5 m/s in the stratosphere while the systematic error requirement be less than 0.7 m/s. The mission spin-off product includes information about aerosol and cloud layers. The satellite flies in a polar dusk/dawn orbit (6 am/pm local time), providing ~16 orbits per 24 hours with an orbit repeat cycle of 7 days. Global scientific payload data acquisition is guaranteed with the combined usage of Svalbard and Troll X-band receiving stations.After almost three years in orbit and despite performance issues related to its instrument ALADIN, Aeolus has achieved most of its objectives. Positive impact on the weather forecast has been demonstrated by multiple NWP centres world-wide with four European meteorological centres now are assimilating Aeolus winds operationally. Other world-wide meteo centers wull start to assimilate data in 2021. The status of the Aeolus mission will be presented, including overall performance, planned operations and exploitation. Scope of the paper is also to inform about the programmatic highlights and future challenges.

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ESA’s Wind Lidar Mission Aeolus – Instrument Performance and Stability

10.5194/egusphere-egu2020-7146 ◽

2020 ◽

Author(s):

Thomas Kanitz ◽

Benjamin Witschas ◽

Uwe Marksteiner ◽

Thomas Flament ◽

Michael Rennie ◽

...

Keyword(s):

Incidence Angle ◽

Weather Prediction ◽

European Space Agency ◽

Positive Outcome ◽

Doppler Lidar ◽

Energy Redistribution ◽

Space Agency ◽

Explorer Mission ◽

Wind Lidar ◽

The Impact

The European Space Agency, ESA deployed the first Doppler wind lidar in space within its Earth Explorer Mission Aeolus in August 2018. After the initial commissioning of the satellite and the single payload ALADIN, the mission has started to demonstrate the capability of Doppler lidar to measure wind from space. In order to provide the best Aeolus wind product possible, detailed monitoring of the instrument is crucial for analysis of system health, but also for the assessment of measurement performance and data product calibration. Within the last 1.2 years the different instrument modes to assess instrument and laser health, as well as the nominal wind processing indicated longterm instrument drifts. The laser beam profile has been monitored and showed an energy redistribution within the beam. The line of sight has slowly drifted, resulting in a change of incidence angle at spectrometer level. The impact of these observed drifts on the wind product are compensated on demand by updates of dedicated ground processing calibration files. This contribution will provide an overview about the Aeolus instrument modes and the observed stability that are needed to provide the Aeolus wind product. The current Aeolus performance has been assessed by various Numerical Weather Prediction centers. The positive outcome is represented by ECMWF&#8217;s decision to start using Aeolus data operationally on 9th January 2020.

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Simulated Doppler Radar Observations of Inhomogeneous Clouds: Application to the EarthCARE Space Mission

Journal of Atmospheric and Oceanic Technology ◽

10.1175/2007jtecha956.1 ◽

2008 ◽

Vol 25 (1) ◽

pp. 26-42 ◽

Cited By ~ 17

Author(s):

N. A. J. Schutgens

Keyword(s):

Doppler Radar ◽

European Space Agency ◽

Space Mission ◽

Information And Communications Technology ◽

Line Of Sight ◽

Radar Observations ◽

Space Agency ◽

Along Track ◽

Japan Aerospace Exploration Agency ◽

Spaceborne Radar

Abstract A new simulation technique for spaceborne Doppler radar observations that was developed specifically for inhomogeneous targets is presented. Cloud inhomogeneity affects Doppler observations in two ways. First, line-of-sight velocities within the instantaneous field of view are unequally weighted. As the large forward motion of a spaceborne radar contributes to these line-of-sight velocities this causes biases in observed Doppler speeds. Second, receiver voltages now have time-varying stochastical properties, increasing the inaccuracy of Doppler observations. The new technique predicts larger inaccuracies of observed Doppler speeds than the traditional random signal simulations based on the inverse Fourier transform. The accuracy of Doppler speed observations by a spaceborne 95-GHz radar [as part of the proposed European Space Agency (ESA)/Japan Aerospace Exploration Agency (JAXA)/National Institute for Information and Communications Technology (NICT) EarthCARE mission] is assessed through simulations for realistic cloud scenes based on observations made by ground-based cloud-profiling radars. Close to lateral cloud boundary biases as large as several meters per second occur. For half of the cloud scenes investigated, the distribution of the in-cloud bias has an rms of 0.5 m s−1, implying that a bias in excess of 0.5 m s−1 will not be uncommon. An algorithm to correct the bias in observed Doppler observations, based on the observed gradient of reflectivity along track, is suggested and shown to be effective; that is, the aforementioned rms bias reduces to 0.14 m s−1.

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The Airborne Demonstrator for the Direct-Detection Doppler Wind Lidar ALADIN on ADM-Aeolus. Part II: Simulations and Rayleigh Receiver Radiometric Performance

Journal of Atmospheric and Oceanic Technology ◽

10.1175/2009jtecha1314.1 ◽

2009 ◽

Vol 26 (12) ◽

pp. 2516-2530 ◽

Cited By ~ 35

Author(s):

Ulrike Paffrath ◽

Christian Lemmerz ◽

Oliver Reitebuch ◽

Benjamin Witschas ◽

Ines Nikolaus ◽

...

Keyword(s):

Direct Detection ◽

European Space Agency ◽

Satellite System ◽

Satellite Mission ◽

Backscatter Signal ◽

Space Agency ◽

Expected Performance ◽

Wind Lidar ◽

Doppler Wind Lidar ◽

Signal Intensities

Abstract In the frame of the Atmospheric Dynamics Mission Aeolus (ADM-Aeolus) satellite mission by the European Space Agency (ESA), a prototype of a direct-detection Doppler wind lidar was developed to measure wind from ground and aircraft at 355 nm. Wind is measured from aerosol backscatter signal with a Fizeau interferometer and from molecular backscatter signal with a Fabry–Perot interferometer. The aim of this study is to validate the satellite instrument before launch, improve the retrieval algorithms, and consolidate the expected performance. The detected backscatter signal intensities determine the instrument wind measurement performance among other factors, such as accuracy of the calibration and stability of the optical alignment. Results of measurements and simulations for a ground-based instrument are compared, analyzed, and discussed. The simulated atmospheric aerosol models were validated by use of an additional backscatter lidar. The measured Rayleigh backscatter signals of the wind lidar prototype up to an altitude of 17 km are compared to simulations and show a good agreement by a factor better than 2, including the analyses of different error sources. First analyses of the signal at the Mie receiver from high cirrus clouds are presented. In addition, the simulations of the Rayleigh signal intensities of the Atmospheric Laser Doppler Instrument (ALADIN) Airborne Demonstrator (A2D) instrument on ground and aircraft were compared to simulations of the satellite system. The satellite signal intensities above 11.5 km are larger than those from the A2D ground-based instrument and always smaller than those from the aircraft for all altitudes.

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Aeolus: ESA’s wind mission. Status and future challenges

10.5194/egusphere-egu2020-4091 ◽

2020 ◽

Author(s):

Tommaso Parrinello ◽

Anne Grete Straume ◽

Jonas Von Bismark ◽

Sebastian Bley ◽

Viet Duc Tran ◽

...

Keyword(s):

European Space Agency ◽

Weather Forecast ◽

Horizontal Line ◽

Space Agency ◽

Future Challenges ◽

The Status ◽

Phase Calibration ◽

Wind Lidar ◽

Operation Phase ◽

Atmospheric Backscatter

The European Space Agency (ESA)&#8217;s wind mission, Aeolus, was launched on 22 August 2018. Aeolus is a member of the ESA Earth Explorer family and its main objective is to demonstrate the potential of Doppler wind Lidars in space for improving weather forecast and to understand the role of atmospheric dynamics in climate variability. Aeolus carries a single instrument called ALADIN: a high sophisticated spectral resolution Doppler wind Lidar which operates at 355 which is the first of its kind to be flown in space. It&#160;provides profiles of single horizontal line-of-sight winds (primary product) in near-real-time (NRT), and profiles of atmospheric backscatter and extinction. The instrument samples the atmosphere from about 30 km down to the Earth&#8217;s surface, or down to optically thick clouds. The required precision of the wind observations is 1-2.5 m/s in the troposphere and 3-5 m/s in the stratosphere while the systematic error requirement be less than 0.7 m/s. The mission spin-off product includes information about aerosol and cloud layers. The satellite flies in a polar dusk/dawn orbit (6 am/pm local time), providing ~16 orbits per 24 hours with an orbit repeat cycle of 7 days. Global scientific payload data acquisition is guaranteed with the combined usage of Svalbard and Troll X-band receiving stations.The status of the Aeolus mission will be provided, including its performance assessment, planned operations and exploitation in the near future. This comprises the outcome of the instrument in its early operation phase, calibration and validation activities and a general review of the main scientific findings. Scope of the paper is also to inform about the programmatic highlights and future challenges.

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PENGENALAN CITRA SATELIT SENTINEL-2 UNTUK PEMETAAN KELAUTAN

OSEANA ◽

10.14203/oseana.2017.vol.42no.3.84 ◽

2017 ◽

Vol 42 (3) ◽

pp. 40-55

Author(s):

Nadya Oktaviani ◽

Hollanda A Kusuma

Keyword(s):

Spatial Resolution ◽

Satellite Image ◽

Atmospheric Correction ◽

European Space Agency ◽

Image Data ◽

Processing Parameters ◽

Cloud Detection ◽

Space Agency ◽

Thin Cloud ◽

Sentinel 2

RECOGNITION AND UTILIZATION OF SATELLITE IMAGE SENTINEL-2 FOR MARINE MAPPING. Sentinel-2 is a satellite launched by a collaboration between The European Commission and the European Space Agency in the Global Monitoring for Environment and Security (GMES) program. The satellite has a mission to scan the Earth’s surface simultaneously at an angle of 180 each satellite with a 5-day temporal resolution with the same appearance on the equator and has a spatial resolution of 10 m, 20 m, and 60 m. There are 13 multispectral channels including VNIR and SWIR. Four channels with 10 m spatial resolution adapt with SPOT 4/5 and user’s comply requirements for land cover classification. Six channels with 20 m spatial resolution becomes a requirement for other Level 2 processing parameters. Channels with 60 m spatial resolution are specified for atmospheric correction and cloud filtering (443 nm for aerosols, 940 nm for moisture, and 1375 for thin cloud detection). Based on these specifications, Sentinel-2 can be an alternative for users to obtain image data with spatial, temporal, radiometric, and spectral resolution is better than SPOT and Landsat. Sentinel-2 can be downloaded for free and easy by the general public. The existence of image by Sentinel-2 is expected to be used optimally, especially for remote sensing analysis in marine field.

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Ganymede’s interaction with the jovian plasma from hybrid simulation

10.5194/epsc2021-683 ◽

2021 ◽

Author(s):

Ronan Modolo ◽

Claire Baskevitch ◽

Francois Leblanc ◽

Adam Masters

Keyword(s):

European Space Agency ◽

Hybrid Simulation ◽

Galilean Satellites ◽

Electrical Currents ◽

Boundary Crossings ◽

Potential Habitat ◽

Cosmic Vision ◽

Space Agency ◽

Explorer Mission ◽

Flowing Plasma

The JUICE (JUpiter ICy moon Explorer) mission, selected by the European Space Agency in May 2012 to be the first large mission within the Cosmic Vision Program 2015&#8211;2025, will provide the most comprehensive exploration to date of the Jovian system in all its complexity, with particular emphasis on Ganymede as a planetary body and potential habitat (JUICE Red Book, 2014). The Galilean satellites are known to have thin atmospheres, technically exospheres (McGrath et al., 2004), produced by ion-induced sputtering and sublimation of the surface materials. These moons and tenuous atmosphere are embedded in the flowing plasma of the jovian. The interaction between the neutral environments of the Galilean satellites and the jovian plasma changes the plasma momentum, the temperature and generates strong electrical currents. In order to prepare the scientific return of the mission and the optimization of operation modes of plasma instruments, a modeling effort has been carried out at LATMOS (PhD R. Allioux, IRAP, 2012; L. Leclercq, LATMOS, 2015; O. Apurva, LATMOS, 2017). A 3D parallel multi-species hybrid model (Latmos Hybrid Simulation, LatHyS) has been developed to model and characterize the plasma environment of Ganymede (Leclercq et al, 2016; Modolo et al, 2016) and a 3D parallel multi-species exospheric model (Exospheric Global Model, EGM) to pattern the dynamic of the neutral envelopes of Ganymede (Turc et al, 2014; Leblanc et al, 2017). The presentation will examine the global structure of the interaction with the jovian plasma, to describe the formation of Alfv&#233;n wings, and to emphasize the phenomena related to the multi-species nature of the plasma. The simulation model supports the preparation of the JUICE mission and its Ganymede phase by characterizing boundary crossings.

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