74 results found
Carli B, Bazzini G, Castelli E, et al., 2007, MARC: A code for the retrieval of atmospheric parameters from millimeter-wave limb measurements, Journal of Quantitative Spectroscopy and Radiative Transfer, Vol: 105, Pages: 476-491, ISSN: 0022-4073
A new data analysis software is presented that has been developed for the retrieval of atmospheric minor constituents from limb-sounding observations made in the millimeter and sub-millimeter spectral regions. The code, which is called MARC (Millimetre-wave Atmospheric-Retrieval Code), has been designed to analyze the observations of the MARSCHALS (Millimetre-wave Airborne Receivers for Spectroscopic CHaracterisation in Atmospheric Limb-Sounding) instrument which operates on the M-55 stratospheric aircraft. The main objective of the analysis of MARSCHALS observations will be to assess long-wave measurement capabilities for the study of the upper troposphere and lower stratosphere regions. The key questions will be the accuracy and spatial resolution that can be achieved by long-wave measurements in presence of clouds and horizontal gradients. MARC performs a global-fit multi-target retrieval, in which optimal estimation is used and errors of the forward model parameters are taken into account for the definition of the cost function minimized in the retrieval. With these features it is easy to use the variables of the problem as either forward model constant parameters or retrieved unknowns with minimum impact on the stability of the retrieval. MARC can perform a wide spectral-band analysis of the observations without a selection of the analyzed channels, and the retrieval process provides an error budget of the retrieved unknowns that includes both the forward model errors and the measurement errors. The error budget obtained in this way is smaller than that obtained when accounting a posteriori for the systematic errors. The new combination of the retrieval features makes possible an efficient and optimal exploitation of the information content of the observations. © 2006 Elsevier Ltd. All rights reserved.
Biancardi M, Cabot R, Magnani L, 2007, The histone methyltransferase G9A adopts a nuclear localization in cleaved porcine embryos, but rarely in pronuclear stage embryos., 40th Annual Meeting of the Society-for-the-Study-of-Reproduction, Publisher: SOC STUDY REPRODUCTION, Pages: 89-89, ISSN: 0006-3363
Johnson C, Magnani L, Cabot R, 2007, Histone methyltransferase glp shows reduced amount of transcript from the GV-stage oocyte to the 8-cell stage in porcine parthenogenetic embryos., 40th Annual Meeting of the Society-for-the-Study-of-Reproduction, Publisher: SOC STUDY REPRODUCTION, Pages: 113-113, ISSN: 0006-3363
Dinelli BM, Arnone E, Brizzi G, et al., 2006, The DCFI-ISAC MIPAS database: 2-D routine analysis of MIPAS observations, ISSN: 0379-6566
The measurements of MIPAS/ENVISAT, in its original nominal observation mode, are analyzed with the GMTR retrieval system in order to obtain 2-D fields of pressure, temperature and Volume Mixing Ratio of H2O, O3, HNO3, CH4, N2O and NO2. The MIPAS level-1b data are archived in the disks cluster of the MIPAS Bologna Facility. The GMTR analysis system, developed in the frame of an ESA supported study, is distributed as part of the BEAT tools. Samples of the obtained results are presented and compared with the corresponding ESA Level 2 MIPAS products.
Carlotti M, Brizzi G, Papandrea E, et al., 2006, GMTR: Two-dimensional geo-fit multitarget retrieval model for michelson interferometer for passive atmospheric sounding/environmental satellite observations, Applied Optics, Vol: 45, Pages: 716-727, ISSN: 1559-128X
We present a new retrieval model designed to analyze the observations of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), which is on board the ENVIronmental SATellite (ENVISAT). The new geo-fit multitarget retrieval model (GMTR) implements the geo-fit two-dimensional inversion for the simultaneous retrieval of several targets including a set of atmospheric constituents that are not considered by the ground processor of the MIPAS experiment. We describe the innovative solutions adopted in the inversion algorithm and the main functionalities of the corresponding computer code. The performance of GMTR is compared with that of the MIPAS ground processor in terms of accuracy of the retrieval products. Furthermore, we show the capability of GMTR to resolve the horizontal structures of the atmosphere. The new retrieval model is implemented in an optimized computer code that is distributed by the European Space Agency as "open source" in a package that includes a full set of auxiliary data for the retrieval of 28 atmospheric targets. © 2006 Optical Society of America.
Magnani L, Fodor W, Machaty Z, et al., 2006, Individual porcine cell lines possess unique expressions pattern of discrete chromatin remodeling factors., 39th Annual Meeting of the Society-for-the-Study-of-Reproduction, Publisher: SOC STUDY REPRODUCTION, Pages: 111-111, ISSN: 0006-3363
Ridolfi M, Magnani L, Carlotti M, et al., 2004, MIPAS-ENVISAT limb-sounding measurements: Trade-off study for improvement of horizontal resolution, Applied Optics, Vol: 43, Pages: 5814-5824, ISSN: 1559-128X
The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) is a limb-scanning spectrometer that has operated onboard the Environmental Satellite since the end of March 2002. Common features of limb-scanning experiments are both high vertical resolution and poor horizontal resolution. We exploit the two-dimensional geo-fit retrieval approach [Appl. Opt. 40, 1872-1875 (2001)] to investigate the possibility of improving the horizontal resolution of MIPAS measurements. Two different strategies are considered for this purpose, one exploiting the possibility (offered by the geo-fit analysis method) for an arbitrary definition of the retrieval grid, the other based on the possibility of saving measurement time by degrading the spectral resolution of the interferometer. The performances of the two strategies are compared in terms of the trade-off between the attained horizontal resolution and the retrieval precision. We find that for ozone it is possible to improve by a factor of 2 the horizontal resolution, which in the nominal measurement plan is ∼530 km. This improvement corresponds to a degradation of the retrieval precision, which on average varies from a factor of 1.4 to 2.5, depending on the adopted spectral resolution. © 2004 Optical Society of America.
Carli B, Alpaslan D, Carlotti M, et al., 2004, First results of MIPAS/ENVISAT with operational Level 2 code, Advances in Space Research, Vol: 33, Pages: 1012-1019, ISSN: 0273-1177
Michelson interferometer for passive atmospheric sounding (MIPAS) is operating on board of the ENVISAT satellite and is acquiring for the first time high spectral resolution middle infrared emission limb sounding spectra of the Earth atmosphere from space. An optimized code was developed for the Level 2 near real time analysis of MIPAS data. The code is designed to provide, in an automated and continuous way, atmospheric vertical profiles of temperature, pressure and concentrations of O3, H2O, CH4, HNO3, N2O and NO2, in the altitude range from 12 to 68 km. The performances of the code are herewith derived from the analysis of the first measurements acquired with this instrument. The assumptions made for the development of the optimized code are verified with the real data. The diagnostics of the instrument performances provide indications that there is good agreements with the results obtained by the Level 1 analysis. Consistent geophysical data are retrieved which is a first step towards a more complete assessment of retrieval accuracy. The tests have identified the possibility of measurement improvements by way of some secondary operations such as a correction of the frequency scale and the use of cloud filtering. However, no change in the algorithm baseline appears to be necessary. © 2003 COSPAR. Published by Elsevier Ltd. All rights reserved.
Dinelli BM, Alpaslan D, Carlotti M, et al., 2004, Multi-target retrieval (MTR): The simultaneous retrieval of pressure, temperature and volume mixing ratio profiles from limb-scanning atmospheric measurements, Journal of Quantitative Spectroscopy and Radiative Transfer, Vol: 84, Pages: 141-157, ISSN: 0022-4073
In this paper we describe a retrieval approach for the simultaneous determination of the altitude distributions of p, T and VMR of atmospheric constituents from limb-scanning measurements of the atmosphere. This analysis method, named multi-target retrieval (MTR), has been designed and implemented in a computer code aimed at the analysis of MIPAS-ENVISAT observations; however, the concepts implemented in MTR have a general validity and can be extended to the analysis of all type of limb-scanning observations. In order to assess performance and advantages of the proposed approach, MTR has been compared with the sequential analysis system implemented by ESA as the level-2 processor for MIPAS measurements. The comparison has been performed on a common set of target species and spectral intervals. The performed tests have shown that MTR produces results of better quality than a sequential retrieval. However, the simultaneous retrieval of p, T and water VMR has not lead to satisfactory results below the tropopause, because of the high correlation occurring between p and water VMR in the troposphere. We have shown that this problem can be fixed extending the MTR analysis to at least one further target whose spectral features decouple the retrieval of pressure and water VMR. Ozone was found to be a suitable target for this purpose. The advantages of the MTR analysis system in terms of systematic errors have also been discussed. © 2003 Elsevier Ltd. All rights reserved.
Piva A, Magnani L, Casadei G, et al., 2004, Influence of diet on microbial community structure and activity in the intestinal tract of weanling pigs, JOURNAL OF DAIRY SCIENCE, Vol: 87, Pages: 28-28, ISSN: 0022-0302
Piva A, Magnani L, Casadei G, et al., 2004, Influence of diet on microbial community structure and activity in the intestinal tract of weanling pigs, POULTRY SCIENCE, Vol: 83, Pages: 28-28, ISSN: 0032-5791
Piva A, Magnani L, Casadei G, et al., 2004, Influence of diet on microbial community structure and activity in the intestinal tract of weanling pigs, JOURNAL OF ANIMAL SCIENCE, Vol: 82, Pages: 28-28, ISSN: 0021-8812
Raspollini F, Carli B, Carlotti M, et al., 2002, Level 2 near real time analysis of MIPAS measurements on ENVISAT, Pages: 324-334, ISSN: 0277-786X
MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) is operating on board of the ENVISAT satellite and is acquiring for the first time high spectral resolution middle infrared emission limb sounding spectra of the Earth atmosphere from space. The measurement capabilities make it possible to determine every 75 sec. the vertical profile of several atmospheric trace constituents, during both day and night with an almost full coverage of the globe. This leads to a three dimensional measurement of the atmospheric composition. In order to handle the large data flow, an optimised code for the Level 2 near real time analysis of MIPAS data was developed by an international consortium of scientists under an ESA contract and was implemented in the ENVISAT Ground Segment. The code is designed to provide, in an automated and continuous mode, atmospheric vertical profiles of temperature and pressure, as well as of concentrations of O3, H2O, CH4, HNO3, N2O and NO2, in the altitude range from 6 to 60 km. The "commissioning phase", in which verification and validation of the instrument and of the analysis code are performed, is still in progress, but some preliminary results have been obtained. The first examples of the MIPAS near real time Level 2 data products, consisting of retrieved profiles and auxiliary data that characterise the measurement accuracy and resolution, are shown.
Ridolfi M, Carlotti M, Dinelli BM, et al., 2002, GEO-FIT approach to the analysis of limb-scanning satellite measurements, Proceedings of SPIE - The International Society for Optical Engineering, Vol: 4539, Pages: 369-380, ISSN: 0277-786X
Retrieval methods for limb-scanning measurements usually adopt the assumption of horizontal homogeneity for the parcel of atmosphere sounded by the analyzed observations. For along-track observations from an orbiting platform, the dimension of the probed parcel of atmosphere may approach 2000 km. Horizontal homogeneity assumption in the inversion algorithms induces an error on the retrieved atmospheric parameters. Two questions arise from these considerations: 1) how to characterize these errors, 2) how to avoid this assumption if the size of the induced errors is not acceptable. In order to answer these questions, an innovative forward and retrieval model (geo-fit) was developed which does not use horizontal homogeneity assumption. In this approach the radiative transfer is made through a two-dimensional inhomogeneous atmospheric field. The retrieval algorithm is based on the simultaneous analysis of all the limb-scanning measurements relating to a given orbit. This feature allows to gather information from several contiguous limb-scanning sequences on a target atmospheric parameter at a given location, and therefore to improve the trade-off between accuracy and horizontal resolution. The obtained results show that the horizontal homogeneity assumption induces a significant systematic error on the retrieved atmospheric parameters, especially in the presence of strong horizontal gradients.
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