切伦科夫望远镜实验，如H.E.S.S.，在甚高能（VHE; E $>$ 100 GeV）区域的天文观测中非常成功。作为探测器的一个组成部分，这种实验使用地球大气作为热量计。对于校准和能量确定，假设标准模型大气。因此，实际大气与模型的偏差可能会导致初级伽马射线的能量重建错误。为了在困难的大气条件下保证令人满意的数据质量，在H.E.S.S.中实施了若干大气数据质量标准。软件这些量对云和气溶胶很敏感。这里，将呈现切伦科夫透明系数。它是一种新的监测量，能够测量大气透明度的长期变化。切伦科夫透明度系数完全来自切伦科夫数据，并且与硬件无关。此外，还将介绍其与多角度成像分光辐射计进行的独立卫星测量的正相关性。
英文摘要：
Cherenkov telescope experiments, such as H.E.S.S., have been very successful in astronomical observations in the very-high-energy (VHE; E $>$ 100 GeV) regime. As an integral part of the detector, such experiments use Earth's atmosphere as a calorimeter. For the calibration and energy determination, a standard model atmosphere is assumed. Deviations of the real atmosphere from the model may therefore lead to an energy misreconstruction of primary gamma rays. To guarantee satisfactory data quality with respect to difficult atmospheric conditions, several atmospheric data quality criteria are implemented in the H.E.S.S. software. These quantities are sensitive to clouds and aerosols. Here, the Cherenkov transparency coefficient will be presented. It is a new monitoring quantity that is able to measure long-term changes in the atmospheric transparency. The Cherenkov transparency coefficient derives exclusively from Cherenkov data and is quite hardware-independent. Furthermore, its positive correlation with independent satellite measurements, performed by the Multi-angle Imaging SpectroRadiometer (MISR), will be presented.
The atmospheric aerosol monitoring system of the Pierre Auger Observatory has been operating smoothly since 2004. Two laser facilities (Central Laser Facility, CLF and eXtreme Laser Facility, XLF) fire sets of 50 shots four times per hour during FD shifts to measure the highly variable hourly aerosol attenuation to correct the longitudinal UV light profiles of the Extensive Air Showers detected by the Fluorescence Detector. Hourly aerosol attenuation loads (Vertical Aerosol Optical Depth) are used to correct the measured profiles. Two techniques are used to determine the aerosol profiles, whic…
Atmospheric multiple scattering of fluorescence light from extensive air showers and effect of the aerosol size on the reconstruction of energy and depth of maximum
Pre-computed aerosol extinction, scattering and asymmetry grids for scalable atmospheric retrievals
Université Paris Cité, Université Paris-Saclay, CEA, CNRS, AIM（巴黎西岱大学、巴黎萨克雷大学、法国原子能和替代能源委员会、法国国家科学研究中心、天体物理学和分子光谱学研究所）；Kapteyn Institute, University of Groningen（卡普坦研究所、格罗宁根大学）
Nighttime monitoring of the aerosol content of the lower atmosphere is a challenging task, because appropriate reference natural light sources are lacking. Here we show that the anthropogenic night sky brightness due to city lights can be successfully used for estimating the aerosol optical depth of arbitrarily thick atmospheric layers. This method requires measuring the zenith night sky brightness with two detectors located at the limiting layer altitudes. Combined with an estimate of the overall atmospheric optical depth (available from ground-based measurements or specific satellite product…
Near-infrared thermal emissivity from ground based atmospheric dust measurements at ORM
我们提出了一个分析在Observatorio del Roque de los Muchachos（ORM;加那利群岛）测得的气溶胶的大气含量。使用位于国家伽利略望远镜（TNG）的激光二极管粒子计数器，我们探测到了0.3，0.5，1.0，3.0，5.0和10.0微米大小的粒子。计算了大气中粉尘含量的季节变化。春季比夏季多尘，但冬季也可能出现多尘情况。提出了一种在近红外波段估算气溶胶发射率对天空亮度贡献的方法。在近红外光谱中，尘埃辐射对天空背景的贡献与气辉相比可以忽略不计，在沙尘天，在Ks波段的贡献最大，约为8-10%。
Launching in 2028, ESA's Atmospheric Remote-sensing Exoplanet Large-survey (ARIEL) survey of $\sim$1000 transiting exoplanets will build on the legacies of Kepler and TESS and complement JWST by placing its high precision exoplanet observations into a large, statistically-significant planetary population context. With continuous 0.5--7.8~$μ$m coverage from both FGS (0.50--0.55, 0.8--1.0, and 1.0--1.2~$μ$m photometry; 1.25--1.95~$μ$m spectroscopy) and AIRS (1.95--7.80~$μ$m spectroscopy), ARIEL will determine atmospheric compositions and probe planetary formation histories during its 3.5-year mi…
A FRAM (F/(Ph)otometric Robotic Atmospheric Monitor) telescope is a system of a robotic mount, a large-format CCD camera and a fast telephoto lens that can be used for atmospheric monitoring at any site when information about the atmospheric transparency is required with high spatial or temporal resolution and where continuous use of laser-based methods for this purpose would interfere with other observations. The original FRAM has been operated at the Pierre Auger Observatory in Argentina for more than a decade, while three more FRAMs are foreseen to be used by the Cherenkov Telescope Array (…
The idea of using stellar photometry for atmospheric monitoring for optical experiments in high-energy astrophysics is seemingly straightforward, but reaching high precision of the order of 0.01 in the determination of the vertical aerosol optical depth (VAOD) has proven difficult. Wide-field photometry over a large span of altitudes allows a fast determination of VAOD independently of the absolute calibration of the system, while providing this calibration as a useful by-product. Using several years of data taken by the FRAM (F/(Ph)otometric Robotic Atmospheric Monitor) telescope at the Pierr…
MRO/CRISM Retrieval of Surface Lambert Albedos for Multispectral Mapping of Mars with DISORT-based Rad. Transfer Modeling: Phase 1 - Using Historical Climatology for Temperatures, Aerosol Opacities, & Atmo. Pressures
Advanced knowledge of the detailed atmospheric properties of both the future sites of the Cherenkov Telescope Array is essential in preparation of the arrival of the first scientific data. Meteorological variables are studied using a dedicated characterization station installed at the southern site in Chile and a wealth of data from existing observatories around the northern site on the La Palma island. Campaigns using radiosondes launched on balloons are foreseen to complement these data in the near future. Cloudiness during the night has been continuously monitored at both sites for several …
The photochemical haze produced in the upper atmosphere of Titan plays a key role in various atmospheric and surface processes on Titan. The surface energy, one important physical properties of the haze, is crucial for understanding the growth of the haze particles and can be used to predict their wetting behavior with solid and liquid species on Titan. We produced Titan analog haze materials, so-called "tholin", with different energy sources and measured their surface energies through contact angle and direct force measurements. From the contact angle measurement, we found that the tholins pr…
As one of the most popular applications of lidar systems, the atmospheric visibility is defined to be inversely proportional to the atmospheric extinction coefficient at 0.55 um. Since the laser at 1.5 um shows the highest maximum permissible exposure in the wavelength ranging from 0.3 um to 10 um, the eye-safe 1.5 um lidar can be deployed in urban areas. In such a case, the measured extinction coefficient at 1.5 um should be converted to that at 0.55 um for visibility retrieval. Although several models have been established since 1962, the accurate wavelength conversion remains a challenge. A…
