基于SBAS/PS-InSAR技术的滑坡遥感监测对比研究     

付波霖  解淑毓  李涛  李豪  左萍萍  高二涛 《大地测量与地球动力学》2021,41(4):392-397

以2015~2019年12景ALOS-2 PALSAR2影像和2018~2019年38景Sentinel-1A影像为主要数据源,利用PS-InSAR和SBAS-InSAR技术提取西藏江达县波罗乡白格滑坡点的形变信息,并对处理结果进行交叉验证。研究得到以下结论：1）PS-InSAR技术条件下,ALOS-2数据和Sentinel-1A数据的平均形变速率范围为-68.9~37.9 mm/a和-64.5~24.2 mm/a;SBAS-InSAR技术条件下,ALOS-2数据和Sentinel-1A数据的平均形变速率范围为-84.2~-40.0 mm/a和-84.0~-13.0 mm/a。2）对2种数据结果中提取的4个特征点进行时序分析和定量分析显示,2种InSAR技术结果变化趋势较为一致,验证了两者在滑坡监测中的可靠性和准确性。  相似文献   

波浪骑士数据在高度计有效波高检验中的再处理     

陈春涛  朱建华  黄骁麒  王贺  赵屹立 《海洋测绘》2013,33(3):53-55

以2011年10～11月南海现场试验得到的9次波浪骑士测量数据,进行波浪骑士再处理与默认计算结果比对。比对结果表明两者平均误差为0.16m,均方根误差为0.32m,分析产生误差的原因在于波浪骑士默认计算有效波高时间段的中心与卫星过境时间不统一和未进行数据质量控制。研究表明在卫星高度计有效波高产品检验中,波浪骑士测量的有效波高需要进行再处理,以达到减少卫星高度计有效波高检验误差的目的。  相似文献   

Fifty-five-year longevity for the largest member of the family Sparidae: the endemic red steenbras Petrus rupestris from South Africa     

《African Journal of Marine Science》2013,35(4):343-353

A previous study that explored the age and growth of red steenbras Petrus rupestris (Valenciennes, 1830), a large sparid (family Sparidae, seabreams or porgies) endemic to South Africa and reported to approach 2 m in length, provided estimates as a moderately slow-growing species with a maximum age near 30 years. The stock is considered collapsed and a fishing moratorium was imposed in 2012, resulting in this species being assessed as Endangered by the IUCN. One consideration in addressing population status is validation of life-history traits. In this study, estimates of age for red steenbras from thin-sectioned otoliths were reassessed visually in terms of both the original ages and revised estimates using a different age-reading pattern. The revised ages exceeded the original ages by up to 30 years, with a maximum estimated age of 55 years from a well-defined otolith section that provided a basis for the revised age-reading procedure. Bomb radiocarbon (¹⁴C) dating revealed there was an offset in the timing of the ¹⁴C rise on the Agulhas Bank that, when coupled with considerations for regional oceanography, provided support for the revised age-reading pattern and an estimated longevity that exceeds 50 years. These findings were further supported by the fortuitous recapture of a tagged red steenbras that was at liberty for 22 years.  相似文献   

Limnology of Bird Pond,Ross Island,Antarctica     

Barbara Spurr 《新西兰海洋与淡水研究杂志》2013,47(4):547-562

The physical, chemical and biological properties of Bird Pond, Cape Bird, Ross Island, Antarctica (77° 13’ 10” S, 166° 28’ 30” E), were investigated at weekly intervals for 2 months in the summer of 1970–71. The above properties were also investigated over a 24‐h period. Salinity and temperature tolerance of the rotifer Philodina gregaria were investigated in the laboratory at Cape Bird.

Bird Pond is characterised by a high conductivity and chloride ion concentration, and an alkaline pH. It has a water temperature as high as 15°c in mid summer, with the bottom water temperature often 3°c higher than the surface temperature. Diurnal measurements suggest a vertical movement of phytoplankton during a 24‐h period. P. gregaria survives ionic concentrations up to 250 000 g.m^‐3 Na⁺ + Cl^‐, and water temperatures up to 32°c.  相似文献   

Comparison of AVHRR measurements of sea surface temperature with surface observations around New Zealand     

Stephen Chiswell  Basil Stanton 《新西兰海洋与淡水研究杂志》2013,47(3-4):303-309

Multi‐channel Advanced Very‐High Resolution Radiometer (AVHRR) images of sea surface temperature (SST) in the New Zealand region have been archived since 1989. A comparison of these data with conductivity‐temperature‐depth (CTD) and expendable bathythermograph (XBT) data shows that the AVHRR temperatures are about 7% too high (when expressed in °C). Once the AVHRR temperatures have been corrected, they measure SST with an uncertainty of about 0.7°C.  相似文献   

Age verification,growth and life history of rubyfish Plagiogeneion rubiginosum     

PL Horn  HL Neil  LJ Paul  PJ McMillan 《新西兰海洋与淡水研究杂志》2013,47(3):353-368

Age verification of rubyfish (Plagiogeneion rubiginosum) was sought using the bomb radiocarbon chronometer procedure. Stable isotopes were investigated for life history characteristics. Radiocarbon (¹⁴C) and stable isotope (δ¹⁸O and δ¹³C) levels were measured in micro-samples from five otoliths that had been aged using a zone count method. All the core ¹⁴C measurements were ‘pre-bomb’ indicating ages of at least 45 years, and the ¹⁴C measurements across the otolith sections suggested that the zone-count ageing method described herein is not biased. Maximum estimated age was 100 years. There was no significant between-sex difference in the von Bertalanffy growth curves. The δ¹⁸O values indicated that rubyfish are near-surface as juveniles, and move deeper with age. Adults appear to reside in 600–1000 m; this is deeper than most trawl-capture data suggest, but not implausible, and has stock assessment implications. The δ¹³C values reflect fish metabolic rates, trophic feeding levels and oceanographic conditions. The stable isotopes record the environmental life history of each fish, and have value in distinguishing stocks and/or indicating vertical and latitudinal migratory patterns.  相似文献   

Long-Term Validation of Wave Height Measurements from Altimeters     

PIERRE QUEFFEULOU 《Marine Geodesy》2013,36(3-4):495-510

Since July 1991, six altimeter missions have been launched successfully, and they have provided almost continuous wave height measurements for more than 12 years. Long-term series of wave height measurements are of major interest for climatology and oceanic wave modeling. Before using such data, the measurements have to be validated, and the homogeneity of the data from various satellites has to be checked. Significant wave height measurements from ERS, TOPEX/Poseidon, GEOSAT Follow-on, Jason-1 and ENVISAT altimeters are validated using cross-altimeter and buoy comparisons. Emphasis is put on the two recent missions Jason-1 and ENVISAT. Corrections for biases and trends are proposed for the six altimeters, allowing the generation of consistent and homogeneous data. Tests of these corrections are performed over global ocean simple statistics.  相似文献   

Simultaneous Ocean Wave Measurements by the Jason and Topex Satellites,with Buoy and Model Comparisons Special Issue: Jason-1 Calibration/Validation     

《Marine Geodesy》2013,36(3-4):367-382

The verification phase of the Jason-1 satellite altimeter mission presents a unique opportunity for comparing near-simultaneous, independent satellite measurements. Here we examine simultaneous significant wave height measurements by the Jason-1 and TOPEX/Poseidon altimeters. These data are also compared with in situ measurements from deep-ocean buoys and with predicted wave heights from the Wave Watch III operational model. The rms difference between Jason and TOPEX wave heights is 28 cm, and this can be lowered by half through improved outlier editing and filtering of high-frequency noise. Noise is slightly larger in the Jason dataset, exceeding TOPEX by about 7 cm rms at frequencies above 0.05 Hz, which is the frequency at which the coherence between TOPEX and Jason measurements drops to zero. Jason wave heights are more prone to outliers, especially during periods of moderate to high backscatter. Buoy comparisons confirm previous reports that TOPEX wave heights are roughly 5% smaller than buoy measurements for waves between 2 and 5 m; Jason heights in general are 3% smaller than TOPEX. Spurious dips in the TOPEX density function for 3- and 6-m waves, a problem that has existed since the beginning of the mission, can be solved by waveform retracking.  相似文献   

First six months quality assessment of HY-2A SCAT wind products using in situ measurements   总被引：4，自引：3，他引：1  

WANG He  ZHU Jianhu  LIN Mingsen  HUANG Xiaoqi  ZHAO Yili  CHEN Chuntao  ZHANG Youguang  PENG Hailong 《海洋学报(英文版)》2013,32(11):27-33

The first Chinese microwave ocean environment satellite HY-2A, carrying a Ku-band scatteromenter （SCAT）, was successfully launched in August 2011. The first quality assessment of HY-2A SCAT wind products is presented through the comparison of the first 6 months operationally released SCAT products with in situ data. The in situ winds from the National Data Buoy Center （NDBC） buoys, R/V Polarstern, Aurora Australis, Roger Revelle and PY30-1 oil platform, were converted to the 10 m equivalent neutral winds. The temporal and spatial differences between the HY-2A SCAT and the in situ observations were limited to less than 5 min and 12.5 km. For HY-2A SCAT wind speed products, the comparison and analysis using the NDBC buoys yield a bias of-0.49 m/s, a root mean square error （RMSE） of 1.3 m/s and an increase negative bias with increasing wind speed observation above 3 m/s. Although less accurate of HY-2A SCAT wind direction at low winds, the RMSE of 19.19° with a bias of 0.92° is found for wind speeds higher than 3 m/s. These results are found consistent with those from R/Vs and oil platform comparisons. Moreover, the NDBC buoy comparison results also suggest that the accuracy of HY-2A SCAT winds is consistent over the first half year of 2012. The encouraging assessment results over the first 6 months show that wind products from HY-2A SCAT will be useful for scientific community.  相似文献   

海洋光学遥感器的辐射定标与数据真实性检验综述   总被引：9，自引：0，他引：9  

陈清莲  唐军武 《海洋技术学报》1998,17(3):13-26

遥感数据定量化应用遥感技术深入发展亟须解决的重要课题,对遥感器进行辐射定标,对遥感数据进行真实性检验的工作已在深入开展,本文介绍了国际关于定标／真实性检验的组织及分工概况,简要阐述了定标／真实性检验的概念与做法,着重讨论了与海洋光学遥感器有关的辐射定标／真实性检验,综述了国外在这方面的若干做法,并在我们工作的基础上提出了开展此项工作的几个关键问题及中能解决的途径。  相似文献