Solar radiometry: Spectral irradiance measurements

The present measurement accuracy of the solar spectral irradiance is insufficient to derive the real long-term solar spectral irradiance variability at all wavelengths. Possible error sources are discussed. A series of new second generation solar irradiance photometers are now under construction which should considerably improve these measurements. At the same time, efforts are made to improve the absolute UV calibration methods to derive a unified UV radiation scale.     

无谐波软X射线单色仪设计

能量在0.1～1keV范围的软X射线辐射在空间科学任务中具有重要应用.飞行前的辐射定标试验及地面辐射定标系统采用传统单色仪分光时,由于波长的整数倍关系带来的高次谐波污染问题非常严重.高次谐波在光束中的占比严重影响了软X射线探测仪器的定标数据精度.本文探讨了无谐波单极衍射技术在产生具有高单色性能的软X射线光束中的应用,基于单极衍射光栅技术实现软X射线无谐波单色仪设计.软X射线无谐波单色仪应用于空间辐射定标系统时能够将高次谐波占比抑制到0.3%以下,满足空间软X射线科学仪器高精度辐射定标试验对高次谐波抑制的要求.      

Proposed optical observations of Comet Halley

A comprehensive programme is proposed for optical observations of Comet Halley based on the wide range of available facilities such as photometers, monochromators, interferometers and a polarimeter. Feasibility study of the proposed investigations with reference to existing facilities is carried out for each technique and needs for additional instrumentation are established. Conclusions for optimum utilization of existing facilities are presented.     

超音速风洞测压的系统统校

风洞实验中经常遇到利用多台仪器测量同一物理量的问题，而各子系统之间的一致性是影响测试准确度的重要因素。就子系统之间的误差对测压实验结果的影响进行了分析并介绍了统校方法。结果表明：子系统本身不确定度比较高，一般不低于０．１％，而多个子系统的分散度相对比较差。因此，利用多套子系统同时测量某一物理量时，有必要进行系统统校；经过统校并作适当处理后，系统的准确度明显提高，实验结果也更趋合理。     

一种手持式校准控制器设计与实现

舰船电工仪表是舰船航行及舰载各动力系统、武器系统、测控系统运行状态的主要判断依据。针对传统的计量校准方法存在的效率低、可靠性难以保证等方面的问题,设计了一种轻便、可靠的手持式校准控制器,控制标准设备输出,同时具备信息录入、数据存储等功能,实现了对舰船电工仪表现场原位快速计量校准,并通过测试数据比对,验证了此方法可行。     

集成运算放大器参数测试仪校准技术研究

集成运算放大器参数测试仪在国家电子行业中广泛使用,其参数测试质量无法保证。研究了集成运放参数测试仪器采用的“闭环测试原理”和目前存在的三种集成运放参数测试仪的校准方案,建立了集成运放参数测试仪校准装置,实现了集成运放参数测试仪的自动化校准。     

Past,present and future measurements of the solar diameter

The solar diameter, and its possible variation, have been the subject of careful measurements for over 350 years, with ever increasing accuracy. The importance of the knowledge of the diameter, and its variation, for solar physics, and climatology are pointed out. Different techniques have been used, and the instrumentation has evolved in time. This is why the long-term evolution of the Sun is still a controversial subject. Even for the short term of the 11-year solar cycle, the results are inconsistent even with the most advanced instruments presently in use. These discrepancies probably have several origins: the Earth’s atmosphere, the spectral domain of observation, the stability of the instruments, and the data filtering techniques used. The absence of either internal angular calibration for most of them, or intercomparisons prior to the operational phase either from ground or space, make understanding the origin of the discrepancies difficult. Not all instruments suffer from all the above defects, but all instruments are affected by at least one of them. Furthermore, the lack of precise definition of what is measured is another source of confusion. We review the available results, and attempt to understand the origin of the discrepancies. Finally, a proposal for future measurements is made.     

A broad spectral band Indian Astronomy satellite ‘Astrosat’

Astrosat will be the first full-fledged Indian Astronomy mission aimed at multiwavelength studies in the optical, near- and far-UV and a broad X-ray spectral band covering 0.5–100 keV. This mission will have the capability of high time-resolution X-ray studies (10 μs timing), low and medium energy-resolution spectral studies and high angular-resolution (about 2″) imaging observations in the UV and optical bands simultaneously. This is realized by using a set of three co-aligned X-ray astronomy instruments and one UV imaging telescope consisting of two similar instruments. Detection and timing studies of X-ray transients and persisting sources will be done by a Scanning Sky X-ray Monitor. This mission will enable studies of different classes of galactic and extragalactic sources in the frontier area of high energy astronomy. Scientific objectives of the mission are highlighted in this paper. A brief summary of the design and characteristics of the X-ray and UV instruments and their expected sensitivities are presented.     

圆度仪测量系统滤波特性的检定

提出一种用定标块检定圆度仪测量系统滤波特性的新方法。该定标块的弦高计算值通过测量系统的各滤波档时必定被衰减。我们可以利用这一弦高值衰减的特点检定其滤波特性。介绍了该方法的检定原理和实验结果。该方法的优点是比用微振动器检定具有更高的效率和更高的准确度，并且可利用检定圆度仪放大倍数的定标块来检定各种圆度仪测量系统的滤波特性。     

舰船现场计量校准环境模拟装置研究

针对原有舰船装备技术状态的压力和电工类仪器仪表计量时，因所处环境较恶劣，存在温湿度、电磁环境、振动等参数不能满足要求而无法开展计量校准工作的问题，设计了一种基于舰船现场计量校准环境的模拟装置。该装置由环境控制和校准操作两部分组成，重点研究了高温环境下的恒温、恒湿技术，以及分体式校准舱结构设计，实现了微环境的自动调节与控制，通过性能试验，证明了校准舱的温度波动度和均匀度均符合设计指标，能够解决现场计量校准的环境条件保障问题。     

Lunar international science coordination/calibration targets (L-ISCT)

Eight lunar areas, each ∼200 km in diameter, are identified as targets for coordinated science and instrument calibration for the orbital missions soon to be flown. Instrument teams from SELENE, Chang’E, Chandrayaan-1, and LRO are encouraged to participate in a coordinated activity of early-release data that will improve calibration and validation of data across independent and diverse instruments. The targets are representative of important lunar terrains and geologic processes and thus will also provide a broad introduction to lunar science for new investigators. We briefly identify additional cross-calibration issues for instruments that produce time series data rather than maps.     

测量设备校准周期调整方法研究

为了选择适合的后续校准周期，通过历史校准数据研究了测量设备校准周期的调整方法。从算法描述、案例分析等方面对校准参数量值预测类方法、周期预测类方法、加权平均法等方法以及周期调整应用软件的发展，进行了分析和研究。结果表明参数量值预测类方法和统计法复杂，准确度高；反应法和改进反应法简单、易行；加权平均法对于多参数、多设备的测量系统具有优势。每种方法都有其特点和适用范围，在实际校准工作中应该根据参数和设备类型、特点、数量，校准过程特点、成本，综合选择校准周期调整方法。     

皮秒级时间间隔定标技术研究

传统的时间间隔产生和测量技术的不确定度只能到1 ns左右,无法满足高速测量需求。介绍了一种新的时间间隔定标技术,利用现有仪器解决了皮秒级时间间隔产生、校准的难题,将皮秒级时间间隔溯源到了时间频率的国防最高标准,实现了小至1 ps的皮秒级时间间隔准确定标技术。     

Introduction to the Payloads and the Initial Observation Results of Chang＇E-1

Chang'E-1,the orbiter circling the moon 200km above the moon surface,is the first Chinese Lunar exploration satellite.The satellite was successfully launched on 24th October 2007.There are 8 kinds of scientific payloads onboard,including the stereo camera,the laser altimeter,the Sagnac-based interferometer image spectrometer,the Gamma ray spectrometer,the X-ray spectrom-eter,the microwave radiometer,the high energy particle detector,the solar wind plasma detector and a supporting payload data management system.Chang'E-1 opened her eyes to look at the moon and took the first batch of lunar pictures after her stereo camera was switched on in 20th November 2007.Henceforth all the instruments are successfully switched on one by one.After a period of parameter adjustment and initial check out,all scientific instruments are now in their normal operating phase.In this paper,the payloads and the initial observation results are introduced.     

Measurement of minor species (H2, Cl,O3, NO) in the earth's atmosphere by the occultation technique

The stellar occultation technique is a clean and powerful means of detecting and quantifying minor gases in the earth's atmosphere. The results obtained are totally insensitive to knowledge of the absolute flux of the star, and are not influenced by instrument calibration problems. Pioneering observations of nocturnal mesospheric ozone and thermospheric molecular oxygen by the stellar occultation technique were made in 1970 and 1971 with the Wisconsin stellar photometers on board the Orbiting Astronomical Observatory-2. A limb crossing geometry was used. The high resolution Princeton ultraviolet spectrometer aboard Copernicus was used in the summers of 1975, 1976 and 1977 to measure altitude profiles of molecular hydrogen, atomic chlorine and nitric oxide in addition to ozone and molecular oxygen. A limb grazing geometry was employed. The ozone densities show wide variation from orbit to orbit and particularly betewen the OAO-2 and Copernicus observations. A H₂ density of 1×10⁸ cm^?3 at 95 km, and a NO density less than 10⁶ cm^?3 for altitudes greater than 85 km were measured.     

Energy deposition in the upper atmosphere in the EXCEDE III experiment

The EXCEDE III sounding rocket flight of April 27, 1990 used a 18 Ampere 2.5 keV electron beam to produce an artificial aurora in the region 90 to 115 km. A “daughter” sensor payload remotely monitored the low-energy X-ray spectrum while scanning photometers measured the spatial profile of prompt emissions of N₂⁺ (1N) and N₂ (2P) transitions (3914Å and 3805Å, respectively). Two Ebert-Fastie spectrometers measured the spectral region from 1800 to 8000Å. On the “mother” accelerator payload, the return current electron differential energy spectra were monitored by an electrostatic analyzer (up to 10 keV) and by a retarding potential analyzer (0 eV to 100 eV). We present an overview of the results from this experiment.     

自动测试系统校准方法研究

自动测试系统的校准是计量界面临的一个新问题,国内还没有相关的校准规范。以实际工程项目为基础,采用一种面向实际应用的自动测试系统校准方法。对于系统中的仪器,根据实际的测试需求及精度不同分别采用仪器检定和仪器校准方法,对于自动测试系统特有的测试通道采用回路标定、替代标定两种标定方法,满足了被测设备的测试准确度要求,实际测试也证明了该方法的可行性。     

Preliminary observing achievements of supersoft X-ray detector and γ-ray detector onboard Shenzhou2

Preliminary observing achievements by the Super Soft X-ray Detector and the γ-ray Detector in the fields of cosmic gamma-ray bursts, solar X-ray, bursts and cosmic X-ray/γ-ray background radiation are summarized. The detectors are aboard the spacecraft Shenzhou-2 that was launched on 2001 January 10. The scientific mission and general situation of the instruments are briefly described.     

电场的标定方法

介绍了球载双球式电场仪、微火箭电场仪和地面旋转式电场仪等3种仪器的标定方法.电场涉及空间物理、空间环境和雷电及地震等多种自然现象的特征参数,对电场的探测或监测应用日益广泛.在我国目前尚未建立电场的国家标准和军用标准的情况下,通过研制的较简易的电场标定系统,对不同结构的电场仪进行标定,均获得了与理论计算相符的结果,为电场测量数据的可信度提供了依据.