光纤外差干涉位移传感器

非接触式光纤外差干涉位移传感器是将半导体激光器线性调频技术和光纤传感技术相结合制成的1种新型外差干涉仪。它的位移测量范围可达26mm，分辨率为0．02μm；对不同材料、不同粗糙度的对象面，有着几乎相同的测量灵敏度和测量精度；探头和对象面无需严格垂直。     

SiC光学反射镜发展现状

主要综述SiC作为光学反射镜材料在设计、制造、光学加工和应用方面的发展现状，同时对今后SiC作为光学镜片材料的发展趋势进行了展望。     

可芯片化的激光抽运Mz型原子磁强计参数研究

激光抽运Mz型原子磁强计具有体积小、功耗低和灵敏度高的优点。介绍了激光抽运Mz型原子磁强计的工作原理，研究了该类型原子磁强计中激光功率和射频场强度对磁共振信号的影响，并对当前实现的原子磁强计样机中射频线圈的磁场强度均匀性对磁共振信号的影响进行了仿真分析。最后，给出了当前实现的原子磁强计样机的性能参数，并讨论了实现芯片级原子磁强计的可行性。     

齿轮接触斑点测量仪光学机械系统的设计分析

介绍１种新近开发的齿轮接触测量仪，该仪器利用先进的ＣＣＤ光电接收器件作测量传感器，并利用ＩＢＭＰＣ／ＸＴ计算机作数据和图象处理，使齿轮接触斑点的测量从测量精度和效率方面都比传统的目视观察，手工描绘提高一大步，本文着重讨论仪器光学机械系统的原理结构。     

一种光纤快速测温系统研究

介绍了一种比色光纤快速测温系统。该系统适合于一些特殊环境下的测温要求，解决了传统测温方法无法测量的问题。它可以用于脉冲爆震发动机温度测量，也可以用于铸造，铸造，高频加热以及陶瓷烧结等测量。     

The optical to X-ray spectrum of the broad-line ultrasoft AGN RE J2248-511

We present a series of monitoring observations of the ultrasoft broad-line Seyfert galaxy RE J2248-511 with XMM-Newton. Previous X-ray observations showed a transition from a very soft state to a harder state five years later. We find that the ultrasoft X-ray excess has re-emerged, yet there is no change in the hard power-law. Reflection models with a reflection fraction of 15, and Comptonisation models with two components of different temperatures and optical depths (kT₁ = 83 keV, T₁ = 30 eV, τ₁ = 0.8; KT₂ = 3.5 keV, T₂ = 60 eV, τ₂ = 2.8) can be fit to the spectrum, but cannot be constrained. The best representation of the spectrum is a model consisting of two blackbodies (kT₁ = 0.09 ± 0.01 keV, kT₂ = 0.21 ± 0.03 keV) plus a power-law (Γ = 1.8 ± 0.08). We also present simultaneous optical and infrared data showing that the optical spectral slope also changes dramatically on timescales of years. If the optical to X-ray flux comes primarily from a Comptonised accretion disk we obtain estimates for the black hole mass , accretion rate and inclination cos(i)  0.8 of the disk.     

Geosynchronous satellites expanding a future GNSS satellite constellation: A precise orbit determination study

The integration of geosynchronous orbit (GSO) satellites in Global Navigation Satellite Systems (GNSS) is mostly discussed to enable a regional enhancement for tracking. But how do GSO satellites affect the orbit determination of the rest of the constellation? How accurately can these orbits be determined in a future GNSS tracking scenario with optical links? In this simulation study we analyze the benefit of GSO satellites as an expansion of a MEO (Medium Earth Orbit) satellite constellation – we selected the Galileo satellite constellation – for MEO Precise Orbit Determination (POD). We address not only the impact on POD of MEO satellites but also the possibility to precisely determine the GSO satellites – geostationary orbits (GEO) and inclined geosynchronous orbits (IGSO) – in such an expanded MEO constellation. In addition to GNSS microwave observations, we analyze the influence of different optical links between the participating entities: Optical two-way Inter-Satellite Links (OISL) and ground-space oriented Optical Two-Way Links (OTWL). These optical measurements together with the GNSS microwave observations give a remarkable benefit for the POD capability. In the case of GNSS and OTWL, we simulate the measurements with regard to a network of 16 ground stations. We pay great attention to the simulation of systematic effects of all measurement techniques. We discuss the influence on the systematic errors as well as the formal orbit uncertainties. A MEO constellation expanded with GSO satellites as well as the use of optical links together with GNSS observations not only improves the MEO satellite orbits but also the GSOs to a great extent.     

Performance improvement of real-time PPP ambiguity resolution using a regional integer clock

Obtaining reliable GNSS uncalibrated phase delay (UPD) or integer clock products is the key to achieving ambiguity-fixed solutions for real-time (RT) precise point positioning (PPP) users. However, due to the influence of RT orbit errors, the quality of UPD/integer clock products estimated with a globally distributed GNSS network is difficult to ensure, thereby affecting the ambiguity resolution (AR) performance of RT-PPP. In this contribution, by fully utilising the consistency of orbital errors in regional GNSS network coverage areas, a method is proposed for estimating regional integer clock products to compensate for RT orbit errors. Based on Centre National d’Études Spatiales (CNES) RT precise products, the regional GPS/BDS integer clock was estimated with a CORS network in the west of China. Results showed that the difference between the estimated regional and CNES global integer clock/bias products was generally less than 5 cm for GPS, whereas clock differences of greater than 10 cm were observed for BDS due to the large RT orbit error. Compared with PPP using global integer clock/bias products, the AR performance of PPP using the regional integer clock was obviously improved for four rover stations. For single GPS, the horizontal and vertical accuracies of ambiguity-fixed PPP solutions were improved by 56.2% and 45.3% on average, respectively, whereas improvements of 67.5% and 50.5% in the horizontal and vertical directions, respectively, were observed for the combined GPS/BDS situation. Based on a regional integer clock, the RMS error of a kinematic ambiguity-fixed PPP solution in the horizontal direction could reach 0.5 cm. In terms of initialisation time, the average time to first fix (TTFF) in combined GPS/BDS PPP was shortened from 18.2 min to 12.7 min. In view of the high AR performance realised with the use of regional integer clocks, this method can be applied to scenarios that require high positioning accuracy, such as deformation monitoring.     

Integrated guidance and control for solar sail station-keeping with optical degradation

Current control approaches for solar sail station-keeping on libration point orbits have not considered the degradation of the sail’s optical properties. However, significant optical degradation could lead to poor station-keeping performance or even complete failure. This paper presents an integrated guidance and control strategy to address this problem by updating the reference orbit based on in situ estimation. An exponential optical degradation model is incorporated into the solar radiation acceleration model, and an on-line reference orbit update approach is incorporated into the station-keeping, coupled with an active disturbance rejection controller. The reflection coefficient is estimated on-line and the reference orbit is updated discretely when the optical properties have degraded by a prescribed amount. This strategy provides discrete updates to the reference orbits such that the perturbation due to the optical degradation is maintained within a small range. These smaller perturbations can be dealt with by the controller’s robustness and station-keeping can be sustained for long durations even in the presence of large optical degradation.     

小型CPT原子钟的数字电路优化研究CSCD

CPT原子钟是一种体积小、功耗低、指标优的新型原子钟。本文对小型CPT原子钟数字滤波算法开展优化研究,采用CIC滤波器前端滤波,低阶FIR滤波器后端滤波。新滤波模块在保证相同的噪声抑制比的情况下,节约逻辑资源,降低整钟功耗。基于以上方案实现的滤波模块,获得了55d B的滤波效果,同时节省了约42%的FPGA逻辑资源。