An improved frequency shift method is proposed to remove the flat earth phase in ATI-SAR ocean surface motion detection in this study. First, two conventional flat earth effect removal methods(i.e., the frequency shif...An improved frequency shift method is proposed to remove the flat earth phase in ATI-SAR ocean surface motion detection in this study. First, two conventional flat earth effect removal methods(i.e., the frequency shift method and the orbital parameter method) are introduced and compared. Then, two improvements to frequency shift method are suggested. In the first improvement, the phase diagram is divided into several sub-blocks to calculate the phase fringe frequency. In the second improvement, a function between the phase of land regions and position is fitted to correct the residual flat earth phase based on the phase of the land regions that tend toward zero in an along-track interferogram. It is found that the improved frequency shift method is greatly improved;and it agrees well with the orbital parameter method, and achieves similar accuracy.展开更多
Concentrations and distribution patterns of rare earth elements(REEs)in the intertidal flat of Tianjin were studied using P(507) resin and ICP-MS analytical technology. The results show that average concentrations of ...Concentrations and distribution patterns of rare earth elements(REEs)in the intertidal flat of Tianjin were studied using P(507) resin and ICP-MS analytical technology. The results show that average concentrations of REEs in the filtered(dissolved REEs), unfiltered and interstitial water are 0.461 μg·L^(-1), 4.98 μg·L^(-1) and 0.845 μg·L^(-1), respectively. Their distribution patterns are similar to those in inland natural rivers, but quite different from those in oceans. The average concentrations of REEs in sediments and suspended matters are 161.2 (mg·L^(-1)) and 168.1 mg·L^(-1), respectively, which are much lower than those in sediments of natural rivers but higher than those in sediments of the continental shelf of East China Sea. It is suggested that REEs in sediments and suspended matters of intertidal flat can have mainly originated from terrestrial soils and thus their transportation and transformation processes are similar with those in rivers, and different from those in continental shelves. Pollutants discharged into the Bohai Bay do·not cause significant effect on REEs in the intertidal flat of Tianjin yet.展开更多
基金The National Key Research and Development Program of China under contract No.2016YFC1402703the National Natural Science Foundation of China under contract Nos 61471136 and 61501130
文摘An improved frequency shift method is proposed to remove the flat earth phase in ATI-SAR ocean surface motion detection in this study. First, two conventional flat earth effect removal methods(i.e., the frequency shift method and the orbital parameter method) are introduced and compared. Then, two improvements to frequency shift method are suggested. In the first improvement, the phase diagram is divided into several sub-blocks to calculate the phase fringe frequency. In the second improvement, a function between the phase of land regions and position is fitted to correct the residual flat earth phase based on the phase of the land regions that tend toward zero in an along-track interferogram. It is found that the improved frequency shift method is greatly improved;and it agrees well with the orbital parameter method, and achieves similar accuracy.
文摘Concentrations and distribution patterns of rare earth elements(REEs)in the intertidal flat of Tianjin were studied using P(507) resin and ICP-MS analytical technology. The results show that average concentrations of REEs in the filtered(dissolved REEs), unfiltered and interstitial water are 0.461 μg·L^(-1), 4.98 μg·L^(-1) and 0.845 μg·L^(-1), respectively. Their distribution patterns are similar to those in inland natural rivers, but quite different from those in oceans. The average concentrations of REEs in sediments and suspended matters are 161.2 (mg·L^(-1)) and 168.1 mg·L^(-1), respectively, which are much lower than those in sediments of natural rivers but higher than those in sediments of the continental shelf of East China Sea. It is suggested that REEs in sediments and suspended matters of intertidal flat can have mainly originated from terrestrial soils and thus their transportation and transformation processes are similar with those in rivers, and different from those in continental shelves. Pollutants discharged into the Bohai Bay do·not cause significant effect on REEs in the intertidal flat of Tianjin yet.
