Infrared Remote Sensing and Instrumentation XXV, 2017
Fourier-spectrometer TIRVIM is a part of ACS spectral complex aboard Mars-Express orbiter spacecr... more Fourier-spectrometer TIRVIM is a part of ACS spectral complex aboard Mars-Express orbiter spacecraft. TIRVIM spectral range is 2–16 micron. It can operate as a spectrometer – with the Sun as a standard radiation source (“occultation” mode) or as a spectro-radiometer (“nadir” mode). In occultation mode the spectral resolution is 0.2 cm-1, in nadir mode – 1.3 cm-1. The main scientific objective of the occultation mode is to search for atmosphere minor constituents, of the nadir mode – to monitor the Mars atmosphere vertical thermal profile (by 15-micron CO2 band). The occultation mode is self-calibrated. For absolute calibration in the nadir mode TIRVIM has a rotating inlet flat mirror (single-axis foreoptic) able to point the FOV (2o) to nadir, space, built-in black-body or to another direction in the plane. TIRVIM mass is 12 kg, the power consumption is 15 W.
Express are reviewed. An average global spectrum ranging from 200 cm to 8200 cm is compared with ... more Express are reviewed. An average global spectrum ranging from 200 cm to 8200 cm is compared with the Martian spectrum from the Short Wavelength Spectrometer of the Infrared Space Observatory (ISO), and with the global synthetic spectrum computed using only the gases CO2, CO and H2O. PFS is able to measure the vertical temperature-pressure profile in the atmosphere and the temperature of the soil simultaneously with the dust and water-ice opacity. The short-wavelength channel shows the major CO2 bands at 4.3 μm and 2.7 μm. The bottom of the first band shows very clearly the non-local thermodynamic equilibrium emission of the high atmospheric CO2 gas, while the limb measurements show CO emission. All the isotopic CO2 molecules appear to be emitting at the same radiance level, implying strong energy pumping from the most abundant to the less abundant molecules. In one of the first passes over Olympus Mons, the temperature field shows abnormal adiabatic cooling in the atmosphere above t...
The ExoMars Trace Gas Orbiter (TGO), a mission by ESA and Roscosmos started its operational scien... more The ExoMars Trace Gas Orbiter (TGO), a mission by ESA and Roscosmos started its operational scientific phase in March 2018. The Atmospheric Chemistry Suite (ACS) is a set of three spectrometers (NIR, MIR, and TIRVIM) designed to observe the Martian atmosphere in solar occultation, nadir and limb geometry [1]. The thermal infrared channel — TIRVIM is a Fourier-transform spectrometer encompassing the spectral range of 1.7–17 μm, with the best spectral resolution 0.13 cm−1. In nadir operation mode, the primary goal of TIRVIM is the long-term monitoring of atmospheric temperature and aerosol (dust and ice clouds) state from the surface to approximately 60 km. We present the results of the first half year operation in orbit around Mars.
optimised for atmospheric studies, covering the IR range of 1.2-45 μm in two channels. The apodis... more optimised for atmospheric studies, covering the IR range of 1.2-45 μm in two channels. The apodised spectral resolution is 2 cm, while the sampling is 1 cm. The FOV is about 2o for the short wavelength (SW) channel and 4o for the long wavelength (LW) channel, corresponding to spatial resolutions of 10 km and 20 km, respectively, from an altitude of 300 km. PFS will also provide unique data on the surface-atmosphere interaction and the mineralogical composition of the surface. It will be the first Fourier spectrometer covering 1-5 μm to orbit the Earth or Mars. The experiment has real-time onboard Fast Fourier Transform (FFT) in order to select the spectral range of interest for data transmission to ground. Measurement of the 15-μm CO2 band is very important. Its profile gives, via a complex temperature-profile retrieval technique, the vertical pressure temperature relation, which is the basis of the global atmospheric study. The SW channel uses a PbSe detector cooled to 200-220K, wh...
ACS onboard the ExoMars TGO) observes the martian atmosphere, using solar occultations and nadir.... more ACS onboard the ExoMars TGO) observes the martian atmosphere, using solar occultations and nadir. Status update of the ACS results obtained during one year of observations with the emphasis on trace gases, and the major dust event will be given.
Infrared Remote Sensing and Instrumentation XXVI, 2018
Atmospheric Chemistry Suite (ACS) is a part of Russian contribution to ExoMars Trace Gas Orbiter ... more Atmospheric Chemistry Suite (ACS) is a part of Russian contribution to ExoMars Trace Gas Orbiter (TGO) ESA-Roscosmos mission. ACS includes three separate infrared spectrometers (MIR, NIR and TIRVIM) with a different spectral coverage and targeted to the different science goals. ACS TIRVIM is a Fourier-transform spectrometer based on 2-inch double pendulum interferometer. It operates in the spectral range of 1.7-7 μm with the best spectral resolution 0.13 cm-1 for solar occultation (SO) mode and 0.8 cm-1 for nadir mode. In nadir mode TIRVIM is purposed to thermal sounding of the Martian atmosphere and aerosol properties retrieval. In SO mode TIRVIM is dedicated to trace gases measurements complementing to ACS MIR. After successful launch of ExoMars TGO on 16 April 2016 there were three time slots for turning on science instruments during cruise phase to execute necessary checks and calibration measurements. In March 2018 the nominal science orbit was reached after cruise and aerobraking phases. The first results of TIRVIM data processing show high performance of the instrument.
Global dust storms develop at Mars at irregular intervals of several years 1,2. They have major e... more Global dust storms develop at Mars at irregular intervals of several years 1,2. They have major effects, causing an inflation of the atmosphere and changes in the dynamical behaviour, primarily due to solar heating of the dust. Recently published observations of Mars' atmospheric water abundance during dust storm conditions revealed a high-altitude increase, more pronounced at high northern latitudes 3,4 , and a decrease in the water column at low latitudes 5,6. These results, however, lacked concurrent measurements of atmospheric dust loading 3 , had a poor vertical resolution 3 , or were indirect 4. The start of science operations with the ESA/ROSCOSMOS ExoMars Trace Gas Orbiter spacecraft coincided with the onset of a global dust storm on Mars. We provide new evidence of the
The Atmospheric Chemistry Suite (ACS) package is an element of the Russian contribution to the ES... more The Atmospheric Chemistry Suite (ACS) package is an element of the Russian contribution to the ESA-Roscosmos ExoMars 2016 Trace Gas Orbiter (TGO) mission. ACS ExoMars-16 Edited by Håkan Svedhem and Christopher T. Russell B O. Korablev
for miniaturized FTIR instruments with a very high spectral resolution (0.05 cm −1 and higher). T... more for miniaturized FTIR instruments with a very high spectral resolution (0.05 cm −1 and higher). The prototype targets measurements of minor atmospheric species from the surface of Mars using the Sun tracking. One important task is to provide a high precision of interferometer's mirror movement. Another task is the development of a precise two-coordinate mechanism to seek for and follow the Sun.
Results of measurements with the Planetary Fourier Spectrometer onboard Mars Express: Clouds and dust at the end of southern summer. A comparison with OMEGA images
This chapter reviews the first year of results from the Planetary Fourier Spectrometer (PFS) of M... more This chapter reviews the first year of results from the Planetary Fourier Spectrometer (PFS) of Mars Express. An average global spectrum ranging from 200 cm-1 to 8200 cm-1 is compared with the martian spectrum from the Short Wavelength Spectrometer of the Infrared Space Observatory (ISO), and with the global synthetic spectrum computed using only the gases CO 2 , CO and H 2 O. PFS is able to measure the vertical temperature-pressure profile in the atmosphere and the temperature of the soil simultaneously with the dust and water-ice opacity. The short-wavelength channel shows the major CO 2 bands at 4.3 µm and 2.7 µm. The bottom of the first band shows very clearly the non-local thermodynamic equilibrium emission of the high atmospheric CO 2 gas, while the limb measurements show CO emission. All the isotopic CO 2 molecules appear to be emitting at the same radiance level, implying strong energy pumping from the most abundant to the less abundant molecules. In one of the first passes over Olympus Mons, the temperature field shows abnormal adiabatic cooling in the atmosphere above the mountain, while the soil temperature of the volcano is higher than the latitudinal profile expectation because of illumination from the Sun. The descending branch of the Hadley cell circulation is studied in detail, with its adiabatic heating and formation of water-ice clouds. Of the many unidentified lines observed, a few have been studied and the presence of methane (10 ppbv), HF (200 ppbv) and HBr (150 ppbv) is reported here. PFS has allowed the study of the composition of the permanent south polar cap: an intimate
The Venus Monitoring Camera (VMC) acquired a set of ultraviolet (UV) images during the Venus Expr... more The Venus Monitoring Camera (VMC) acquired a set of ultraviolet (UV) images during the Venus Express mission unprecedented in its duration from May 2006 to September 2013. Here we present the results of digital tracking of the cloud features in the upper cloud layer at latitudes 25-751S using images from 257 orbits with the best spatial coverage. The method relies on analysis of correlations between pairs of UV images separated in time. The bulk of data processed allows us to clarify the reasons why the midlatitude jet is not always present in latitudinal wind profiles. Comparing VMC images with wind velocity fields we found a relationship between cloud morphology at middle latitudes and the circulation. The vector field in middle latitudes depends on the presence of a contrast global streak in the cloud morphology tilted with respect to latitude circles. The angle of the flow deflection (the angle between the wind velocity and latitudinal circles) and the difference of the zonal velocity on the opposite sides of the streak are in direct relationship to the angle between the streak and latitude circles. During such orbits the jet bulge does not appear in the latitudinal profile of the zonal wind component. Otherwise a zonal flow with small changes of the meridional velocity dominates in middle latitudes and manifests itself as a jet bulge. The relationship between the cloud cover morphology and circulation peculiarities can be attributed to the motion of global cloud features, like the Y-feature. We prepared plots of zonal and meridional velocities averaged with respect to the entire observation period. The average zonal velocity has a diurnal maximum at 15:00 local solar time and at 401S. The meridional velocity reaches its maximum between 13:00 and 16:00 and at 501S. The velocities obtained by the digital method are in good agreement with results of the visual method in the middle latitudes published earlier by Khatuntsev et al. (2013).
A relatively simple eye-safe compact solid-state lidar for measuring the aerosol backscatter coef... more A relatively simple eye-safe compact solid-state lidar for measuring the aerosol backscatter coefficient and cloud height has been developed and tested. The performance of the laser radar based on the semiconductor laser and Single Photon Avalanche Diode as a receiver are discussed. The lidar produces detailed the backscatter coefficient profiles within a hundred meters in daytime with a signal-to-noise ratio
PFS: the Planetary Fourier Spectrometer for Mars Express
The Planetary Fourier Spectrometer (PFS) for the Mars Express mission is optimised for atmospheri... more The Planetary Fourier Spectrometer (PFS) for the Mars Express mission is optimised for atmospheric studies, covering the IR range of 1.2-45 mum in two channels. The apodised spectral resolution is 2 cm-1, while the sampling is 1 cm-1. The FOV is about 2° for the short wavelength (SW) channel and 4° for the long wavelength (LW) channel, corresponding to spatial
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Papers by D. Patsaev