An approach to aid INS using time-differenced GPS carrier phase (TDCP) measurements   总被引：1，自引：0，他引：1  

Ben K. H. Soon  Steve Scheding  Hyung-Kuen Lee  Hung-Kyu Lee  Hugh Durrant-Whyte 《GPS Solutions》2008,12(4):261-271

This paper presents a simple and effective approach that incorporates single-frequency, L1 time-differenced GPS carrier phase (TDCP) measurements without the need of ambiguity resolution techniques and the complexity to accommodate the delayed-state terms. Static trial results are included to illustrate the stochastic characteristics and effectiveness of the TDCP measurements in controlling position error growth. The formulation of the TDCP observation model is also described in a 17-state tightly-coupled GPS/INS iterative, extended Kalman filter (IEKF) approach. Preliminary land vehicle trial results are also presented to illustrate the effectiveness of the TDCP which provides sub-meter positional accuracies when operating for more than 10 min.  相似文献   

Analysis of solar radiation on the surface estimated from GWNU solar radiation model with temporal resolution of satellite cloud fraction     

Il-Sung Zo  Joon-Bum Jee  Kyu-Tae Lee  Bu-Yo Kim 《Asia-Pacific Journal of Atmospheric Sciences》2016,52(4):405-412

Preliminary analysis with a solar radiation model is generally performed for photovoltaic power generation projects. Therefore, model accuracy is extremely important. The temporal and spatial resolutions used in previous studies of the Korean Peninsula were 1 km × 1 km and 1-h, respectively. However, calculating surface solar radiation at 1-h intervals does not ensure the accuracy of the geographical effects, and this parameter changes owing to atmospheric elements (clouds, aerosol, ozone, etc.). Thus, a change in temporal resolution is required. In this study, one-year (2013) analysis was conducted using Chollian geostationary meteorological satellite data from observations recorded at 15-min intervals. Observation data from the intensive solar site at Gangneung-Wonju National University (GWNU) showed that the coefficient of determination (R²), which was estimated for each month and season, increased, whereas the standard error (SE) decreased when estimated in 15-min intervals over those obtained in 1-h intervals in 2013. When compared with observational data from 22 solar sites of the Korean Meteorological Administration (KMA), R² was 0.9 or higher on average, and over- or under-simulated sites did not exceed 3 sites. The model and 22 solar sites showed similar values of annual accumulated solar irradiation, and their annual mean was similar at 4,998 MJ m^?2 (3.87 kWh m^?2). These results show a difference of approximately ± 70 MJ m^?2 (± 0.05 kWh m^?2) from the distribution of the Korean Peninsula estimated in 1-h intervals and a higher correlation at higher temporal resolution.  相似文献   

Nutrient (N,P, Si) concentration and primary production on a perturbed tropical coastal mudflat     

Hong Wooi Teoh  Soon Loong Lee  Ving Ching Chong  Tatsuya Yurimoto 《Environmental Earth Sciences》2016,75(15):1147

  相似文献   

Glacier Extent and Volume Change （1966-9000） on the Su-lo Mountain in Northeastern Tibetan Plateau, China     

WANG Yetang HOU Shugui HONG Sungmin HUR Soon Do LIU Yaping 《山地科学学报》2008,5(4)

  相似文献   

Down-scaled regional ocean modeling system (ROMS) for high-resolution coastal hydrodynamics in Korea   总被引：1，自引：0，他引：1  

LIM Hak-Soo  KIM Chang S  PARK Kwang-Soon  SHIM Jae Seol  CHUN Insik 《海洋学报(英文版)》2013,32(9):50-61

A down-scaled operational oceanographic system is developed for the coastal waters of Korea using a regional ocean modeling system(ROMS).The operational oceanographic modeling system consists of atmospheric and hydrodynamic models.The hydrodynamic model,ROMS,is coupled with wave,sediment transport,and water quality modules.The system forecasts the predicted results twice a day on a 72 h basis,including sea surface elevation,currents,temperature,salinity,storm surge height,and wave information for the coastal waters of Korea.The predicted results are exported to the web-GIS-based coastal information system for real-time dissemination to the public and validation with real-time monitoring data using visualization technologies.The ROMS is two-way coupled with a simulating waves nearshore model,SWAN,for the hydrodynamics and waves,nested with the meteorological model,WRF,for the atmospheric surface forcing,and externally nested with the eutrophication model,CE-QUAL-ICM,for the water quality.The operational model,ROMS,was calibrated with the tidal surface observed with a tide-gage and verified with current data observed by bottom-mounted ADCP or AWAC near the coastal waters of Korea.To validate the predicted results,we used real-time monitoring data derived from remote buoy system,HF-radar,and geostationary ocean color imager(GOCI).This down-scaled operational coastal forecasting system will be used as a part of the Korea operational oceanographic system(KOOS) with other operational oceanographic systems.  相似文献   

Simulation of the extreme waves generated by typhoon Bolaven (1215) in the East China Sea and Yellow Sea     

JUN Ki Cheon  JEONG Weon Mu  CHOI Jin Yong  PARK Kwang Soon  JUNG Kyung Tae  KIM Mee Kyung  CHAE Jang Won  QIAO Fangli 《海洋学报(英文版)》2015,34(12):19-28

Record-breaking high waves occurred during the passage of the typhoon Bolaven (1215) (TYB) in the East China Sea (ECS) and Yellow Sea (YS) although its intensity did not reach the level of a super typhoon. Winds and directional wave measurements were made using a range of in-situ instruments mounted on an ocean tower and buoys. In order to understand how such high waves with long duration occurred, analyses have been made through measurement and numerical simulations. TYB winds were generated using the TC96 typhoon wind model with the best track data calibrated with the measurements. And then the wind fields were blended with the reanalyzed synoptic-scale wind fields for a wave model. Wave fields were simulated using WAM4.5 with adjustment of C_d for gust of winds and bottom friction for the study area. Thus the accuracy of simulations is considerably enhanced, and the computed results are also in better agreement with measured data than before. It is found that the extremely high waves evolved as a result of the superposition of distant large swells and high wind seas generated by strong winds from the front/right quadrant of the typhoon track. As the typhoon moved at a speed a little slower than the dominant wave group velocity in a consistent direction for two days, the wave growth was significantly enhanced by strong wind input in an extended fetch and non-linear interaction.  相似文献   

Differential rotation of some HK-Project stars and the butterfly diagrams     

M.M. Katsova  M.A. Livshits  W. Soon  S.L. Baliunas  D.D. Sokoloff   《New Astronomy》2010,15(2):274-281

We analyze the long-term variability of the chromospheric radiation of 20 stars monitored in the course of the HK-Project at the Mount Wilson Observatory. We apply the modified wavelet algorithm for this set of gapped time series. Besides the mean rotational periods for all these stars, we find reliable changes of the rotational periods from year to year for a few stars. Epochs of slower rotation occur when the activity level of the star is high, and the relationship repeats again during the next maximum of an activity cycle. Such an effect is traced in two stars with activity cycles that are not perfectly regular (but labeled “Good” under the classification in [Baliunas, S.L., Donahue, R.A., Soon, W.H., Horne, J.H., Frazer, J., Woodard-Eklund, L., Bradford, M., Rao, L.M., Wilson, O.C., Zhang, Q. et al., 1995. ApJ 438, 269.]) but the two stars have mean activity levels exceed that of the Sun. The averaged rotational period of HD 115404 is 18.5 days but sometimes the period increases up to 21.5 days. The sign of the differential rotation is the same as the Sun’s, and the value ΔΩ/Ω=-0.14. For the star HD 149661, this ratio is −0.074. Characteristic changes of rotational periods occur over around three years when the amplitude of the rotational modulation is large. These changes can be transformed into latitude-time butterfly diagrams with minimal a priori assumptions. We compare these results with those for the Sun as a star and conclude that epochs when surface inhomogeneities rotate slower are synchronous with the reversal of the global magnetic dipole.  相似文献   

SPH modeling of tidal bore scenarios     

Liu  Huaxing  Li  Jing  Shao  Songdong  Tan  Soon Keat 《Natural Hazards》2015,75(2):1247-1270

Natural Hazards - The paper presented a smoothed particle hydrodynamics (SPH) method to study the three-dimensional (3D) tidal bore scenarios. The SPH method is a mesh-free particle modeling...  相似文献   

Role of the Radiation Factor in Global Climatic Events of the Late Holocene     

Fedorov  V. M.  Frolov  D. M.  Velasco Herrera  V. M. N.  Soon  W. W.-H.  Cionco  R. G. 《Izvestiya Atmospheric and Oceanic Physics》2021,57(10):1239-1253

Izvestiya, Atmospheric and Oceanic Physics - On the basis of calculations of insolation and insolation characteristics, taking into account changes in solar activity, the causes of global climatic...  相似文献   

TBT toxicity on the marine microalga Nannochloropsis oculata     

M. Sidharthan  Kim Shin Young  Lee Hoe Woul  Park Kwan Soon  Hyun Woung Shin   《Marine pollution bulletin》2002,45(1-12)

Commercial antifouling formulations containing TBT are the major source of organotin contamination in coastal waters. In view of the persisting TBT residues (13 ng Sn l⁻¹) in the coastal waters of South Korea, an attempt has been made to evaluate the growth response and biochemical composition of laboratory-cultured Nannochloropsis oculata to TBT toxicity. It is evident that the persisting concentration level of TBT is high enough to cause adverse effect on the microalgal species. The EC₅₀ (24 h) was found to be at 0.89 nM level of TBT for this marine eustigmatophyte N. oculata. Photosynthetic pigment content was significantly affected. At elevated TBT concentrations of 1.0 nM, especially pronounced changes in biochemical composition was found. TBT tolerance of N. oculata and its growth as well as biochemical responses are discussed.  相似文献