發(fā)布時間：2018-04-21 16:29

  本文選題：大氣視寧度 + 夜天光亮度��； 參考：《新疆大學(xué)》2017年碩士論文

【摘要】：提高光學(xué)望遠(yuǎn)鏡探測暗弱目標(biāo)和分辨其細(xì)節(jié)的能力不僅需要成熟的望遠(yuǎn)鏡制造技術(shù)和高精度控制,還需要在良好的觀測條件下才能充分發(fā)揮光學(xué)望遠(yuǎn)鏡的重要作用。所以一臺造價不菲光學(xué)望遠(yuǎn)鏡的建成,總要先經(jīng)過對選址點(diǎn)觀測環(huán)境長期、系統(tǒng)的測量工作后才最終選址建立。而對于建成后的光學(xué)望遠(yuǎn)鏡,為保證其能夠科學(xué)、合理、高效的運(yùn)行,對臺址的觀測環(huán)境監(jiān)測也必須長期有效。本論文首先介紹了光學(xué)臺址的勘選要素,包括大氣視寧度、夜天光亮度、大氣水汽和氣象條件,并分析了監(jiān)測原理與方法以及不同測量儀器的優(yōu)劣,最后對南山站的光學(xué)觀測環(huán)境長期監(jiān)測進(jìn)行數(shù)據(jù)處理和分析。大氣視寧度是決定光學(xué)望遠(yuǎn)鏡成像質(zhì)量的重要參數(shù),是用來描述復(fù)雜大氣湍流對觀測目標(biāo)星像產(chǎn)生綜合作用程度的物理量,也決定著望遠(yuǎn)鏡成像受限的極限口徑。南山站視寧度監(jiān)測工作中使用SBIG視寧度儀對臺站的視寧度條件進(jìn)行了長期監(jiān)測。本研究工作計(jì)算分析了視寧度的月變化、夜間各時段的均值變化等,最終得到南山站的視寧度值FWHM為1.74”。夜天光來源于地面以上的自然光以及人為光源等,會使觀測時的天空背景變亮,直接影響觀測的極限星等。南山站在夜天光亮度的監(jiān)測工作中使用SQM夜天光亮度計(jì),獲得了連續(xù)的監(jiān)測數(shù)據(jù)。本研究工作通過逐日查閱氣象觀測日志選擇全晴夜觀測數(shù)據(jù),利用貝塞爾公式將粗大誤差數(shù)據(jù)剔除,再進(jìn)一步統(tǒng)計(jì)每日記錄的最大值,最終計(jì)算得無月情況下南山站可見光波段的夜天光亮度為21.7mag arcsec-2。大氣水汽在紅外觀測波段存在著寬度為10nm-100nm間斷的吸收帶,如果望遠(yuǎn)鏡進(jìn)行紅外波段的觀測,則對大氣水汽含量有著極為苛刻的要求,通常不能高于0.4g/cm2。此外,臺站觀測環(huán)境監(jiān)測的內(nèi)容還包括保證望遠(yuǎn)鏡及其他天文儀器正常工作的溫度、相對濕度、風(fēng)速等。在對南山站的大氣水汽以及氣象參數(shù)的監(jiān)測工作中使用CE-318型太陽光度計(jì)和PC-4型四要素自動氣象站。通過對年均大氣水汽含量、年均溫濕度值、風(fēng)速等進(jìn)行分析計(jì)算,最終得到臺站年均大氣水汽含量均值為0.9g/cm2,年平均溫度為3.4℃,年平均相對濕度為57.3%,風(fēng)速主要分布區(qū)間為2-3m/s,主要風(fēng)向?yàn)槲髂巷L(fēng)。我們在本工作中使用的測量方法和積累的經(jīng)驗(yàn)以及測量結(jié)果也可為國內(nèi)其他光學(xué)臺址起到對比參考作用。
[Abstract]:To improve the ability of optical telescopes to detect dark and weak targets and distinguish their details requires not only mature telescope manufacturing techniques and high precision control, but also good observation conditions to give full play to the important role of optical telescopes. Therefore, a costly optical telescope must be built after a long period of site observation environment, system measurement work before the establishment of the final location. For the completed optical telescope, in order to ensure its scientific, reasonable and efficient operation, the observation environment monitoring of the site must also be effective for a long time. This paper first introduces the elements of optical site selection, including atmospheric apparent degree, night sky brightness, atmospheric water vapor and meteorological conditions, and analyzes the monitoring principles and methods as well as the merits and demerits of different measuring instruments. Finally, the long-term monitoring of optical observation environment in Nanshan station is processed and analyzed. Atmospheric visibility is an important parameter that determines the imaging quality of optical telescopes. It is a physical quantity used to describe the comprehensive action of complex atmospheric turbulence on the satellite image of the observed target, and it also determines the limited aperture of the imaging of the telescope. In the monitoring work of apparent Nanning degree of Nanshan Station, the condition of apparent Ning degree of the station was monitored by SBIG instrument for a long time. In this paper, the monthly variation of apparent Ning degree and the mean value of night time are calculated and analyzed. Finally, the FWHM of Nanshan Station is 1. 74 ". The night sky light comes from the natural light above the ground and the artificial light source, which will make the sky background brighten and directly affect the observation limit magnitude. In the monitoring work of night sky luminance, Nanshan uses SQM night sky luminance meter to obtain continuous monitoring data. In this study, the meteorological observation log was consulted day by day to select the all night observation data, the coarse error data was eliminated by using Bessel formula, and the maximum value of daily record was further counted. Finally, it is calculated that the night sky brightness of the visible light band of Nanshan station is 21.7mag arcsec-2 without moon. Atmospheric water vapor has an absorption band with a width of 10nm-100nm discontinuity in the infrared observation band. If the telescope makes observations in the infrared band, the atmospheric water vapor content is very demanding, and usually cannot be higher than 0.4 g / cm ~ (2). In addition, the monitoring of observational environment includes the temperature, relative humidity and wind speed of telescope and other astronomical instruments. In the monitoring of atmospheric water vapor and meteorological parameters in Nanshan station, CE-318 solar photometer and PC-4 automatic weather station with four elements are used. Through the analysis and calculation of average annual atmospheric water vapor content, average annual temperature and humidity value, wind speed and so on, the average annual average atmospheric water vapor content of the station is 0.9g / cm ~ 2 and the annual average temperature is 3.4 鈩，

本文編號：1783208