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1.
Estimation of elevation-dependent satellite antenna phase center variations of GPS satellites 总被引:16,自引:7,他引:9
A method for the estimation of the phase center variations of GPS satellite antennas using global GPS data is presented. First estimations have shown an encouraging repeatability from day to day and between satellites of the same block. Thus, two different satellite antenna patterns for Block II/IIA and for Block IIR with a range of about 4 cm and an accuracy of less than 1 mm could be found. The present approach allows the creation of a consistent set of receiver and satellite antenna patterns and phase center offsets. Thereby, it is possible to switch from relative to absolute phase center variations without a scale problem in global networks. This changeover has an influence on troposphere parameters, reduces systematic effects due to uncorrect antenna modeling and should diminish the elevation dependence of GPS results.
AcknowledgmentsThe authors thank Prof. G. Seeber (University of Hannover) and Dr. G. Wübbena (Geo++ GmbH) and their groups for their kindness in making available the absolute field calibration results derived from robot measurements. 相似文献
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在高精度GNSS定位中,接收机天线相位中心偏差(PCO)和天线相位中心变化(PCV)的影响不可忽略。目前,IGS发布的绝对天线相位模型文件中包含了GPS/GLONASS系统的标定值,但是没有发布北斗系统(BDS)的标定值。本文借助机械臂可以控制天线自由旋转,在数小时内实现全方位GNSS观测的特性,采用历元间差分的方法对接收机天线包括GPS L1/L2和BDSB1I/B2I/B3I等多个频点的PCO和PCV分别进行标定和拟合。标定结果表明,比较最小二乘估计的GPS PCO与IGS发布值,其STD和RMS在L1/L2上均小于1 mm;BDS PCO估计值的STD在B1I/B2I/B3I上分别为0.5、0.3、0.3 mm。利用球谐函数拟合的GPS PCV格网值与IGS发布值相比,其偏差在天顶距小于75°时均小于1.5 mm。BDS PCV拟合值范围均在-5~8 mm,且随天顶距变化曲线呈现波谷状。BDS PCV在低高度角处拟合值波动较大,随方位角变化曲线峰值-峰值最大达到了5.6 mm。 相似文献
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GPS天线相位中心变化及测试 总被引:3,自引:1,他引:3
对GPS天线相位中心随卫星变化的情况及减小和消除天线相位中心误差的方法进行了阐述 ,并详细介绍了对两种型号GPS天线相位中心变化进行比较和测试的结果 相似文献
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天线相位中心改正对GPS精密单点定位的影响 总被引:1,自引:0,他引:1
GPS卫星与接收机由于自身特性以及机械加工等原因,导致其质量中心与相位中心不重合而产生相位中心误差,进而对GPS精密单点定位产生一定影响。介绍GPS天线相位中心偏移(PCO)、变化(PCV)的原理,并分析PCO、PCV,以及不同模型改正对GPS精密单点定位的影响。结果表明,在GPS精密单点定位中,天线相位中心改正不容忽略:在平面方向上,天线相位中心改正对定位影响较小,仅为毫米级;在高程方向上,天线相位中心改正对定位影响较大,可达厘米级;与相对中心改正模型相比,绝对相位中心改正模型精度更高。 相似文献
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GPS接收机噪声对天线相位中心检测的影响分析 总被引:3,自引:0,他引:3
利用四天的零基线观测数据,截取不同时间长度的数据段,解算出北方向、东方向、高程方向的偏差量△N、△E、△U,对这些偏差量进行统计分析和误差分析。 相似文献
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Phase variations of GPS receiving antennas are a significant error component in precise GPS applications. A calibration procedure
has been developed by Geo++ and the Institut für Erdmessung, which directly determines absolute phase center variations (PCVs)
without any multipath influence by field measurements. The precision and resolution of the procedure allows the determination
of reliable azimuthal variations. PCV may affect long-term static GPS differently than real-time GPS, depending on the applications.
At the same time, different antenna types are involved. Less investigations have been done on absolute PCV of rover antennas
than on geodetic antennas which, however, becomes more important due to the mixed antenna situation in GPS reference networks
and RTK networks. The concepts of the absolute PCV field calibration are summarized and emphasis is placed on a variety of
absolute PCV patterns of geodetic and rover antennas.
Electronic Publication 相似文献
11.
一种顾及现势指向的上行天线阵相位中心精确标校方法 总被引:1,自引:0,他引:1
针对上行天线阵相位中心标校技术粗糙、精度不高等问题,引入精密工程测量技术测定天线实际状态,提出了一种顾及现势指向的相位中心精确标校方法。首先,利用工业摄影测量系统获取天线各姿态的型面数据,并通过最小二乘法拟合求解出现势性强的机械轴;然后,用矩阵法解算各姿态下机械轴的交点作为旋转中心;最后,基于反角度加权插值法推估得到天线在任意姿态下的机械轴,进而从投影中心沿机械轴延伸既定长度获得可靠的相位中心。以3台φ3 m上行阵天线为试验对象,通过工程控制网统一摄影测量坐标系,并按照本文方法标校天线相位中心。电信号合成效果表明,本文方法能有效克服天线自重变形、机械安装等因素的影响,实现了相位中心的精确标校,增强了上行天线阵合成信号的幅度。 相似文献
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Influence of different GPS receiver antenna calibration models on geodetic positioning 总被引:1,自引:0,他引:1
Q. Baire C. Bruyninx J. Legrand E. Pottiaux W. Aerts P. Defraigne N. Bergeot J. M. Chevalier 《GPS Solutions》2014,18(4):529-539
To better understand how receiver antenna calibration models contribute to GPS positioning error budget, we compare station positions estimated with different calibration models: igs05.atx, igs08.atx and individual antenna calibrations. First, the impact of switching from the igs05.atx antenna calibration model to the igs08.atx antenna calibration model is investigated using the EUREF Permanent Network historical data set from 1996 until April 2011. It is confirmed that these position offsets can be effectively represented by the igs05.atx to igs08.atx latitude-dependent model. Then, we demonstrate that the position offsets resulting from the use of individual calibrations instead of type mean igs08.atx calibrations can reach up to 1 cm in the up component, while in the horizontal, the offsets generally stay below 4 mm. Finally, using six antennas individually calibrated by a robot as well as in an anechoic chamber, we observe a position agreement of 2 mm in the horizontal component and a bias of 5 mm in the up component. Larger position offsets, dependent on the antenna/radome type, are, however, found when these individual calibrations are compared to type mean calibrations of two tested antennas. 相似文献
16.
Estimation of satellite antenna phase center offsets for Galileo 总被引:2,自引:1,他引:1
P. Steigenberger M. Fritsche R. Dach R. Schmid O. Montenbruck M. Uhlemann L. Prange 《Journal of Geodesy》2016,90(8):773-785
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L. E. Sjöberg 《Journal of Geodesy》1999,73(3):118-124
With access to dual-frequency pseudorange and phase Global Positioning System (GPS) data, the wide-lane ambiguity can easily
be fixed. Advantage is taken of this information in the linear combination of the above four observables for base ambiguity
estimation (i.e. of N
1 and N
2). Starting points for our analysis are the Best Linear Unbiased Estimators BLUE1 and BLUE2. BLUE1 is the best one (with minimum mean square error, MSE) if the ionosphere effect is negligible. If this is not the case, BLUE2 has the smallest variance, but not necessarily the least mean square error. Hence, both estimators may suffer from a non-optimal
treatment of the ionosphere bias. BLUE1 ignores possible ionosphere bias, while BLUE2 compensates for this bias in a less favourable way by eliminating it at the price of increased noise. As an alternative,
linear estimators are derived, which make a compromise between the ionosphere bias and the random observation errors. This
leads to the derivation of the Best Linear Estimator (BLE) and the Restricted Best Linear Estimator (RBLE) with minimum MSE.
The former is generally not very useful, while the RBLE is recommended for practical use. It is shown that the MSE of the
RBLE is limited by the variances of BLUE1 and BLUE2, i.e.
However, as is always the case with a BLE, it cannot be used strictly: some parameter (in this case the ionosphere bias) must
be approximately known.
Received: 25 June 1997 / Accepted: 16 November 1998 相似文献
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针对接收机天线相位中心与天线参考点ARP不一致引起的测量误差,从距离域和位置域分析其对定位精度的影响.同时,顾及IGS未提供接收机端Galileo天线相位中心改正,采用GPS的天线相位中心改正近似替代,并进行精密单点定位和静态相对定位.结果表明,天线相位中心偏差引起测距的误差可达1 dm,应当改正;采用近似PCO与PCV改正后,PPP垂向偏差由dm-cm级提高到mm级,不同接收机天线相对定位的垂向偏差由cm级提高到mm级,近似替代策略可明显改善Galileo精密定位的精度. 相似文献
19.
Oliver Montenbruck Miquel Garcia-Fernandez Yoke Yoon Steffen Schön Adrian Jäggi 《GPS Solutions》2009,13(1):23-34
Phase center variations of the receiver and transmitter antenna constitute a remaining uncertainty in the high precision orbit
determination (POD) of low Earth orbit (LEO) satellites using GPS measurements. Triggered by the adoption of absolute phase
patterns in the IGS processing standards, a calibration of the Sensor Systems S67-1575-14 antenna with GFZ choke ring has
been conducted that serves as POD antenna on various geodetic satellites such as CHAMP, GRACE and TerraSAR-X. Nominal phase
patterns have been obtained with a robotic measurement system in a field campaign and the results were used to assess the
impact of receiver antenna phase patterns on the achievable positioning accuracy. Along with this, phase center distortions
in the actual spacecraft environment were characterized based on POD carrier phase residuals for the GRACE and TerraSAR-X
missions. It is shown that the combined ground and in-flight calibration can improve the carrier phase modeling accuracy to
a level of 4 mm which is close to the pure receiver noise. A 3.5 cm (3D rms) consistency of kinematic and reduced dynamic
orbit determination solutions is achieved for TerraSAR-X, which presumably reflects the limitations of presently available
GPS ephemeris products. The reduced dynamic solutions themselves match the observations of high grade satellite laser ranging
stations to 1.5 cm but are potentially affected by cross-track biases at the cm-level. With respect to the GPS based relative
navigation of TerraSAR-X/TanDEM-X formation, the in-flight calibration of the antenna phase patterns is considered essential
for an accurate modeling of differential carrier phase measurements and a mm level baseline reconstruction.
相似文献
Oliver MontenbruckEmail: |
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GPS Solutions - Precise positioning using the signals of the Global Position System requires correcting the distance between the points of reception of the signal carrier phase and the antenna... 相似文献