Comparison and research of group refractivity models and atmospheric delay to lidar

2018 ◽  
Author(s):  
Jiuying Chen ◽  
Mei Zhou ◽  
Geer Teng ◽  
Huijing Zhang ◽  
Jian Hu ◽  
...  
Keyword(s):  
Atmospheric Delay

Impact of Atmospheric Delay Reduction Using KARAT on GPS/PPP Analysis

2011 ◽  
pp. 781-787 ◽  
Author(s):  
Ryuichi Ichikawa ◽  
Thomas Hobiger ◽  
Yasuhiro Koyama ◽  
Tetsuro Kondo
Keyword(s):  
Delay Reduction ◽  
Atmospheric Delay

Sensitivity Analysis of Atmospheric Delay Corrections for Satellite-Borne Laser Altimeter

2019 ◽  
Vol 56 (23) ◽  
pp. 230101
Author(s):  
江丹 Jiang Dan ◽  
覃驭楚 Qin Yuchu ◽  
王小平 Wang Xiaoping
Keyword(s):  
Sensitivity Analysis ◽  
Laser Altimeter ◽  
Atmospheric Delay

scholarly journals Comparison and Calculation of Different Atmospheric Delay Models Using Atmospheric Parameters of VLBI Stations of China

1993 ◽  
Vol 156 ◽  
pp. 212-212
Author(s):  
Zhigen Yang
Keyword(s):  
Elevation Angle ◽  
Mapping Function ◽  
Physical Models ◽  
Lapse Rate ◽  
Tropospheric Temperature ◽  
Atmospheric Parameters ◽  
Temperature Lapse Rate ◽  
Atmospheric Delay ◽  
Vlbi Observations ◽  
The Difference

The values of the atmospheric time delay for the “Chao”, “Marini” and “CfA−2.2” mapping function are calculated by using the atmospheric parameters in summer and winter at Shanghai, Kunming and Urumqi station respectively. A comparison among these values shows that the derivations of “Marini” from “Chao” and “CfA” are relatively large. On the other hand, the difference of values between the “Chao” and the “CfA” in the case of ∊ = 40° ∼ 10°, which is the average for the three stations, is from +1 mm to +47 mm for the “wet” part of the delay in summer, while is from −2 mm to −28 mm for the “dry” part in winter. For the case of low elevation angle ɛ ≐ 5°, the difference for the “wet” part can be about 400 mm in summer. Therefore, it is indispensable to make a further comparison between “Chao” and “CfA” mapping function by using the data of VLBI observations, in order to make a better revision to the adopted models of atmospheric delay.The monthly averages of the height of tropopause ht and the tropospheric temperature lapse rate βt for the three stations mentioned above are used to calculate the dry atmospheric delay by the “CfA” mapping function. The results show that the amplitudes of the annual changing of delay dτa, which is caused by ht and βt for the case of ∊ = 20° ∼ 10° at Urumqi station, are about 1 ∼ 5 mm and 2 ∼ 15 mm respectively. Therefore, taking the parameters of ht and βt of the stations into account in “CfA” model, instead of using fixed constants, would be much favourable for the requirements of 1 ps precision of VLBI physical models.

Database of Crustal Deformation Observed by SAR: Improving Atmospheric Delay Mitigation for Satellite SAR Interferometry and Developing L-Band Multi-Type Portable SAR

2019 ◽  
Vol 14 (5) ◽  
pp. 713-727
Author(s):  
Taku Ozawa ◽  
Yosuke Aoki ◽  
Satoshi Okuyama ◽  
Xiaowen Wang ◽  
Yousuke Miyagi ◽  
...  
Keyword(s):  
Human Resource Development ◽  
Crustal Deformation ◽  
Sar Interferometry ◽  
Japan Meteorological Agency ◽  
Numerical Weather ◽  
Numerical Weather Model ◽  
Atmospheric Delay ◽  
Weather Model ◽  
L Band ◽  
Volcanic Activities

Spaceborne synthetic aperture radar (SAR) and ground-based radar interferometers (GBRIs) can be used to detect spatially detailed crustal deformations that are difficult to detect by on-site observations, the Global Navigation Satellite System, tiltmeters, and so on. To make such crustal deformation information readily available to those engaged in evaluating volcanic activities and researching the mechanisms, we are preparing a database within the Japan Volcanological Data Network data sharing system to store crustal deformation detected by spaceborne SAR and GBRIs (Subtheme 2-1, Project B, the Integrated Program for Next Generation Volcano Research and Human Resource Development). In this study, we examined methods to reduce atmospheric delay noise in SAR interferometry using the numerical weather model and determined the methods for resampling the analytical values of the numerical weather model and estimating atmospheric delay to efficiently determine atmospheric delay. We show that the atmospheric delay can be estimated with higher accuracy by properly combining the isobaric surface and ground surface data of the mesoscale model (MSM) provided by the Japan Meteorological Agency. We are developing a multi-type portable SAR system as a GBRI system such that it would allow campaign observations whenever increased volcanic activities are observed and acquire crustal deformation with a higher temporal resolution than spaceborne SAR for storage in the database. This system employs L-band radar, which has a higher penetrability against vegetation. Two modes of observations are possible: ground-based SAR and car-borne SAR. The prototype was fabricated to conduct experiments necessary to develop a working model. The experimental observations was carried out around Asama volcano, and we confirmed that clear fringe was obtained.

Anisotropy of atmospheric delay in InSAR and its effect on InSAR atmospheric correction

2018 ◽  
Vol 93 (2) ◽  
pp. 241-265 ◽  
Author(s):  
Jianchao Wei ◽  
Zhiwei Li ◽  
Jun Hu ◽  
Guangcai Feng ◽  
Meng Duan
Keyword(s):  
Atmospheric Correction ◽  
Atmospheric Delay

Testing a Medium-Range DGPS Network for the Taiwan Area

1999 ◽  
Vol 52 (2) ◽  
pp. 279-288 ◽  
Author(s):  
C. C. Chang ◽  
S. H. Lin
Keyword(s):  
Sufficient Accuracy ◽  
Reference Station ◽  
Test Results ◽  
Positioning Accuracy ◽  
Atmospheric Delay ◽  
Medium Range ◽  
Differential Corrections ◽  
Highly Correlated ◽  
Operational Range ◽  
Taiwan Area

The DGPS technique can be used for navigation over baselines up to approximately 100 km. However, DGPS positioning accuracy is highly correlated and degraded with the extension of its operational range. It is, hence, improper simply to carry on using conventional DGPS for navigation over longer ranges. An approach aimed at providing sufficient accuracy with the use of a minimum network of reference stations, and the modelling of GPS errors, has been proposed and tested for regional navigation over the Taiwan area. It has been shown from the test results that medium-range DGPS based on using multi-reference stations is capable of improving the RMS coordinate differences by 35%, when compared to the use of a single reference station. The RMS values can be further improved by 14% and 6% in plan coordinates and height respectively, when the modelling of atmospheric delay is applied to the differential corrections based on the pseudorange observables collected from the multi-reference stations.

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