Ground Calibration of Solar X-ray Monitor On-board Chandrayaan-2 Orbiter
N. P. S. Mithun, Santosh V. Vadawale, M. Shanmugam, Arpit R. Patel, Neeraj Kumar Tiwari, Hiteshkumar L. Adalja, Shiv Kumar Goyal, Tinkal Ladiya, Nishant Singh, … 展开作者
N. P. S. Mithun, Santosh V. Vadawale, M. Shanmugam, Arpit R. Patel, Neeraj Kumar Tiwari, Hiteshkumar L. Adalja, Shiv Kumar Goyal, Tinkal Ladiya, Nishant Singh, Sushil Kumar, Manoj K. Tiwari, M. H. Modi, Biswajit Mondal, Aveek Sarkar, Bhuwan Joshi, P. Janardhan, Anil Bhardwaj
Chandrayaan-2, the second Indian mission to the Moon, carries a spectrometer called the Solar X-ray Monitor (XSM) to perform soft X-ray spectral measurements of the Sun while a companion payload measures the fluorescence emission from the Moon. Together these two payloads will provide quantitative estimates of elemental abundances on the lunar surface. XSM is also expected to provide significant contributions to the solar X-ray studies with its highest time cadence and energy resolution spectral measurements. For this purpose, the XSM employs a Silicon Drift Detector and carries out energy measurements of incident photons in the 1 -- 15 keV range with a resolution of less than 180 eV at 5.9 keV, over a wide range of solar X-ray intensities. Extensive ground calibration experiments have been carried out with the XSM using laboratory X-ray sources as well as X-ray beam-line facilities to determine the instrument response matrix parameters required for quantitative spectral analysis. This includes measurements of gain, spectral redistribution function, and effective area, under various observing conditions. The capability of the XSM to maintain its spectral performance at high incident flux as well as the dead-time and pile-up characteristics have also been investigated. The results of these ground calibration experiments of the XSM payload are presented in this article.
The Solar X-ray Monitor (abbreviated as XSM) on board India's Chandrayaan-2 mission is designed to carry out broadband spectroscopy of the Sun from lunar orbit. It observes the Sun as a star and measures the spectrum every second in the soft X-ray band of 1 - 15 keV with an energy resolution better than 180 eV at 5.9 keV. The primary objective of the XSM is to provide the incident solar spectrum for the X-ray fluorescence spectroscopy experiment on the Chandrayaan-2 orbiter, which aims to generate elemental abundance maps of the lunar surface. However, observations with the XSM can independent…
Solar X-ray Monitor (XSM) is one of the scientific instruments on-board Chandrayaan-2 orbiter. The XSM along with instrument CLASS (Chandras Large Area Soft x-ray Spectrometer) comprise the remote X-ray fluorescence spectroscopy experiment of Chandrayaan-2 mission with an objective to determine the elemental composition of the lunar surface on a global scale. XSM instrument will measure the solar X-rays in the energy range of 1-15 keV using state-of-the-art Silicon Drift Detector (SDD). The Flight Model (FM) of the XSM payload has been designed, realized and characterized for various operating…
Surface chemistry of airless bodies in the solar system can be derived from remote x-ray spectral measurements from an orbiting spacecraft. X- rays from planetary surfaces are excited primarily by solar x-rays. Several experiments in the past have used this technique of x-ray fluorescence for deriving abundances of the major rock forming elements. The Chandrayaan- 2 orbiter carries an x-ray fluorescence experiment named CLASS that is designed based on results from its predecessor C1XS flown on Chandrayaan-1. We discuss the new aspects of lunar science that can be potentially achieved with CLAS…
Alpha Particle X-ray Spectrometer (APXS) is one of the two scientific experiments on Chandrayaan-2 rover named as Pragyan. The primary scientific objective of APXS is to determine the elemental composition of the lunar surface in the surrounding regions of the landing site. This will be achieved by employing the technique of X-ray fluorescence spectroscopy using in-situ excitation source Cm-244 emitting both X-rays and alpha particles. These radiations excite characteristic X-rays of the elements by the processes of particle induced X-ray emission (PIXE) and X-ray fluorescence (XRF). The chara…
Context. The Metis coronagraph is one of the remote-sensing instruments of the ESA/NASA Solar Orbiter mission. Metis is aimed at the study of the solar atmosphere and solar wind by simultaneously acquiring images of the solar corona at two different wavelengths; visible-light (VL) within a band ranging from 580 nm to 640 nm, and in the HI Ly-alpha 121.6 +/- 10 nm ultraviolet (UV) light. The visible-light channel includes a polarimeter with electro-optically modulating Liquid Crystal Variable Retarders (LCVRs) to measure the linearly polarized brightness of the K-corona to derive the electron d…
A Point-Spread Function for the Extreme Ultraviolet High-Resolution Imager on board Solar Orbiter
Columbia Astrophysics Laboratory, Columbia University（哥伦比亚大学天体物理实验室）；Solar-Terrestrial Centre of Excellence – SIDC, Royal Observatory of Belgium（比利时皇家天文台太阳-地球卓越中心SIDC）；Centre Spatial de Liège, Université de Liège（列日大学空间研究中心）；Max Planck Institute for Solar System Research（马克斯·普朗克太阳系研究所）；Université Paris-Saclay, CNRS, Institut d’Astrophysique Spatiale（巴黎萨克雷大学，法国国家科学研究中心，天体物理研究所）
The Metis coronagraph is one of the remote sensing instruments hosted on board the ESA/NASA Solar Orbiter mission. Metis is devoted to carry out the first simultaneous imaging of the solar corona in both visible light (VL) and ultraviolet (UV). High-energy particles penetrate spacecraft materials and may limit the performance of on-board instruments. A study of galactic cosmic-ray (GCR) tracks observed in the first VL images gathered by Metis during the commissioning phase for a total of 60 seconds of exposure time is presented here. A similar analysis is planned for the UV channel. A predicti…
Solar X-ray Monitor (XSM) instrument of India's Chandrayaan-2 lunar mission carries out broadband spectroscopy of the Sun in soft X-rays. XSM, with its unique features such as low background, high time cadence, and high spectral resolution, provides the opportunity to characterize transient and quiescent X-ray emission from the Sun even during low activity periods. It records the X-ray spectrum at one-second cadence, and the data recorded on-board are downloaded at regular intervals along with that of other payloads. During ground pre-processing, the XSM data is segregated, and the level-0 dat…
Context. The Spectrometer/Telescope for Imaging X-rays (STIX) is one of 6 remote sensing instruments on-board Solar Orbiter. It provides hard X-ray imaging spectroscopy of solar flares by sampling the Fourier transform of the incoming flux. Aims. To show that the visibility amplitude and phase calibration of 24 out of 30 STIX sub-collimators is well advanced and that a set of imaging methods is able to provide the first hard X-ray images of the flaring Sun from Solar Orbiter. Methods. We applied four visibility-based image reconstruction methods and a count-based one to calibrated STIX observa…
Modelling spacecraft-emitted electrons measured by SWA-EAS experiment on board Solar Orbiter mission
Institute of Atmospheric Physics of the Czech Academy of Sciences（捷克科学院大气物理研究所）；Astronomical Institute of the Czech Academy of Sciences（捷克科学院天文研究所）；Czech Technical University in Prague（布拉格捷克理工大学）；Mullard Space Science Laboratory, University College London（伦敦大学学院穆拉德空间科学实验室）；Swedish Institute of Space Physics (IRF)（瑞典空间物理研究所）；LIRA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Univers（巴黎天文台 LIRA 实验室，PSL 大学，法国国家科学研究中心，索邦大学）
Cross-Calibration of Chandrayaan-2 XSM with INSPIRESat-1 DAXSS and GOES-16 XRS
Physical Research Laboratory（物理研究实验室）；Space Applications Centre, Indian Space Research Organisation（印度空间研究组织空间应用中心）；Laboratory for Atmospheric and Space Physics, University of Colorado Boulder（科罗拉多大学博尔德分校大气与空间物理实验室）；Space Sciences Laboratory, University of California Berkeley（加州大学伯克利分校空间科学实验室）；Southwest Research Institute（西南研究所）；Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder（科罗拉多大学博尔德分校环境科学研究合作学院）；NOAA National Centers for Environmental Information（美国国家海洋和大气管理局国家环境信息中心）
Spectro-polarimetry of HAbitable Planet Earth (SHAPE) on Chandrayaan-3: Instrument characteristics, calibration and onboard performance
Space Astronomy Group, ISITE-Campus, U. R. Rao Satellite Centre（空间天文组，ISITE校园，U.R. Rao卫星中心）；U. R. Rao Satellite Centre（U.R. Rao卫星中心）；Laboratory for Electro-Optics Systems（光电系统实验室）
The Polarimetric and Helioseismic Imager (PHI) is the first deep-space solar spectropolarimeter, on-board the Solar Orbiter (SO) space mission. It faces: stringent requirements on science data accuracy, a dynamic environment, and severe limitations on telemetry volume. SO/PHI overcomes these restrictions through on-board instrument calibration and science data reduction, using dedicated firmware in FPGAs. This contribution analyses the accuracy of a data processing pipeline by comparing the results obtained with SO/PHI hardware to a reference from a ground computer. The results show that for t…
École Polytechnique Federale de Lausanne（洛桑联邦理工学院）；University of Bern（伯尔尼大学）；INAF, Osservatorio Astronomico di Padova（意大利国家天体物理研究所帕多瓦天文台）；RUAG Space；Idiap Research Institute（Idiap 研究所）
There are many geometric calibration methods for "standard" cameras. These methods, however, cannot be used for the calibration of telescopes with large focal lengths and complex off-axis optics. Moreover, specialized calibration methods for the telescopes are scarce in literature. We describe the calibration method that we developed for the Colour and Stereo Surface Imaging System (CaSSIS) telescope, on board of the ExoMars Trace Gas Orbiter (TGO). Although our method is described in the context of CaSSIS, with camera-specific experiments, it is general and can be applied to other telescopes.…
In order to allow for a comparison with the measurements from other antenna systems, the voltage power spectral density measured by the Radio and Plasma waves receiver (RPW) on board Solar Orbiter needs to be converted into physical quantities that depend on the intrinsic properties of the radiation itself.The main goal of this study is to perform a calibration of the RPW dipole antenna system that allows for the conversion of the voltage power spectral density measured at the receiver's input into the incoming flux density. We used space observations from the Thermal Noise Receiver (TNR) and …
The extension of on-board data processing capabilities is an attractive option to reduce telemetry for scientific instruments on deep space missions. The challenges that this presents, however, require a comprehensive software system, which operates on the limited resources a data processing unit in space allows. We implemented such a system for the Polarimetric and Helioseismic Imager (PHI) on-board the Solar Orbiter (SO) spacecraft. It ensures autonomous operation to handle long command-response times, easy changing of the processes after new lessons have been learned and meticulous book-kee…
This paper describes the Polarimetric and Helioseismic Imager on the Solar Orbiter mission (SO/PHI), the first magnetograph and helioseismology instrument to observe the Sun from outside the Sun-Earth line. It is the key instrument meant to address the top-level science question: How does the solar dynamo work and drive connections between the Sun and the heliosphere? SO/PHI will also play an important role in answering the other top-level science questions of Solar Orbiter, as well as hosting the potential of a rich return in further science. SO/PHI measures the Zeeman effect and the Doppler …
Solar flares are the most powerful events in the solar system and the brightest sources of X-rays, often associated with emission of particles reaching the Earth and causing geomagnetic storms, giving problems to communication, airplanes and even black-outs. X-rays emitted by accelerated electrons are the most direct probe of solar flare phenomena. The Micro Solar-Flare Apparatus (MiSolFA) is a proposed compact X-ray detector which will address the two biggest issues in solar flare modeling. Dynamic range limitations prevent simultaneous spectroscopy with a single instrument of all X-ray emitt…
The ESA/NASA Solar Orbiter space mission has been successfully launched in February 2020. Onboard is the Polarimetric and Helioseismic Imager (SO/PHI), which has two telescopes, a High Resolution Telescope (HRT) and the Full Disc Telescope (FDT). The instrument is designed to infer the photospheric magnetic field and line-of-sight velocity through differential imaging of the polarised light emitted by the Sun. It calculates the full Stokes vector at 6 wavelength positions at the Fe I 617.3 nm absorption line. Due to telemetry constraints, the instrument nominally processes these Stokes profile…
Università degli Studi di Genova（热那亚大学）；CNR-SPIN（国家研究委员会SPIN研究所）
Space telescopes for solar hard X-ray imaging provide observations made of sampled Fourier components of the incoming photon flux. The aim of this study is to design an image reconstruction method relying on enhanced visibility interpolation in the Fourier domain. % methods heading (mandatory) The interpolation-based method is applied on synthetic visibilities generated by means of the simulation software implemented within the framework of the Spectrometer/Telescope for Imaging X-rays (STIX) mission on board Solar Orbiter. An application to experimental visibilities observed by the Reuven Ram…
