- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Oil Slick Detection in the Offshore Domain: Evaluation of Polarization-Dependent Sar Parameters
摘要： Remote sensing technology is an essential link in the global monitoring of the ocean surface and radars are efficient sensors for detecting marine pollution. When used operationally, a tradeoff must usually be made between the covered area and the quantity of information collected by the radar. To identify the most appropriate imaging mode, a methodology based on Receiver Operating Characteristic (ROC) curve analysis has been applied to an original dataset collected by an airborne system, SETHI, characterized by a very low instrument noise floor. The dataset was acquired during an oil spill clean-up exercise carried out in 2015 in the North Sea. Various polarization-dependent quantities are investigated and a relative ordering of the main polarimetric parameters is reported. VV offers the best tradeoff between the benefit of detection performance and the instrument and data requirements. When the sensor has a sufficiently low noise floor, HV is also recommended because it provides strong slick-sea contrast. Among all the investigated quad-polarimetric settings, no significant added value compared to single-polarized data was found.
关键词： NESZ,noise floor,sea,spill,detection,SAR,noise,slick,radar,marine pollution,probability of detection,oil,ROC curves,probability of false alarm,ocean,polarization
更新于2025-09-23 15:23:52
-
Radiative transition probabilities between low-lying electronic states of N <sub/>2</sub>
摘要： This work mainly investigates the transition dipole moments (TDMs) and radiative transition probabilities of dipole-allowed transitions between the b1Σu+, a''1Σg+, 13Σg-, 23Σg-, C'3Σu+, B'3Σu-, W3Δu, 23Σu+ and H3Υu states of N2. Many of these transition properties are previously unknown. For completeness, another 14 electronic states that correlate to four lowest dissociation limits are also calculated. The potential energy curves (PECs) are calculated at the valence internally contracted multireference configuration-interaction (icMRCI) level of theory, along with the Davidson correction, the core-valence (CV) correction and the scalar relativistic correction, as well as the basis-set extrapolation. These corrections, especially the CV correction, greatly improve the accuracy of the PECs, as shown by the excellent agreement of the fitted spectroscopic parameters with the available experimental data. In order to verify the accuracy of transition properties, we calculate the Einstein coefficients of the extensively studied B3Σg- - A3Σu+, C3Σu+ - B3Σg-, W3Δu - B3Σg-, B'3Σu- - B3Σg-, C'3Σu+ - B3Σg-, w1Δu - a1Σg+, a1Σg+ - a'1Σg- and b1Σu+ - X1Σg+ band transition systems and compute the radiative lifetimes of N2 B3Σg-, C3Σu+ and W3Δu states, which are in good agreement with the experimental data. Similar accuracy can be assumed for the previously undetermined 13Σg- - B'3Σu-, 23Σg- - B'3Σu-, 23Σg- - C'3Σu+, 23Σu+ - B3Σg- and b1Σu+ - a''1Σg+ band transition systems. The large Einstein coefficients of these band systems can provide guidelines for observing such newly predicted band transitions in the appropriate spectroscopy experiments.
关键词： radiative lifetime,Spectroscopic parameter,radiative transition probability,transition dipole moment,N2
更新于2025-09-23 15:23:52
-
Quantum Sphere-Packing Bounds with Polynomial Prefactors
摘要： We study lower bounds on the optimal error probability in classical coding over classical-quantum channels at rates below the capacity, commonly termed quantum sphere-packing bounds. Winter and Dalai have derived such bounds for classical-quantum channels; however, the exponents in their bounds only coincide when the channel is classical. In this paper, we show that these two exponents admit a variational representation and are related by the Golden-Thompson inequality, reaf?rming that Dalai’s expression is stronger in general classical-quantum channels. Second, we establish a ?nite blocklength sphere-packing bound for classical-quantum channels, which signi?cantly improves Dalai’s prefactor from the order of subexponential to polynomial. Furthermore, the gap between the obtained error exponent for constant composition codes and the best known classical random coding exponent vanishes in the order of o(log n/n), indicating our sphere-packing bound is almost exact in the high rate regime. Finally, for a special class of symmetric classical-quantum channels, we can completely characterize its optimal error probability without the constant composition code assumption. The main technical contributions are two converse Hoeffding bounds for quantum hypothesis testing and the saddle-point properties of error exponent functions.
关键词： Hoeffding bounds,classical-quantum channels,symmetric channels,quantum sphere-packing bounds,polynomial prefactor,error probability,saddle-point properties,finite blocklength
更新于2025-09-23 15:23:52
-
Detection probability for moving ground target of normal distribution using infrared satellite
摘要： In this article, we discuss the detection probability for a moving ground target such as vehicles using an infrared imaging satellite. In the ?rst part, we discuss a basic detection model for a regional ground target using a satellite. The probability of detection is calculated. In the second part, a basic model for the recognition of a ground target using an infrared imaging satellite is developed based on the model in the ?rst part. Based above two parts,we discuss a basic model of the detection probability for a moving ground target using an infrared imaging satellite in the third part. As the normal distribution has the maximum entropy, we analyze the normal distribution of a moving ground target such as some vehicles, and based on our conclusions, we develop a basic probability model for the detection of a moving ground target using an infrared imaging satellite. Finally, the simulation was carried on by STK software.
关键词： Moving ground target,Normal distribution,Detection probability,Regional ground target,Infrared light imaging satellite
更新于2025-09-23 15:23:52
-
10?Gbps CPRI signals transmission impaired by intercore crosstalk in 5G network fronthauls with multicore fibers
摘要： The impact of intercore crosstalk (ICXT) of weakly-coupled multicore fibers (MCFs) on the transmission performance of a Common Public Radio Interface (CPRI) signal in 5G networks fronthaul is studied by numerical simulation. The results show that forward error correction-supported CPRI signals have more tolerance to ICXT due to the higher targeted bit error rate (of 10?3). For a receiver power penalty of 1 dB, an improvement of the tolerance of CPRI signals to ICXT, due to the increase of the MCF skew by about 1 dB, is observed. However, for the crosstalk levels that lead to 1 dB power penalty, we have shown that, the system is unavailable with a high probability. The crosstalk level required for an acceptable outage probability is about 10 dB lower than the crosstalk level leading to 1 dB power penalty.
关键词： 5G wireless networks,Multicore fiber,Common public radio interface,Outage probability,Intercore crosstalk,Bit error rate
更新于2025-09-23 15:23:52
-
Physical Layer Security of Hybrid Satellite-FSO Cooperative Systems
摘要： In this paper, we study the physical layer secrecy performance of a hybrid satellite and free-space optical (FSO) cooperative system. The satellite links are assumed to follow the Shadowed-Rician fading distribution; and the channel of the terrestrial link between the relay and destination is assumed to experience the Gamma-Gamma fading. For the FSO communications, the effects of different types of detection techniques (i.e., heterodyne detection and intensity modulation with direct detection) as well as the pointing error are considered. We derive exact analytical expressions for the average secrecy capacity (ASC) and secrecy outage probability (SOP) for both cases of Amplify-and-Forward (AF) and Decode-and-Forward (DF) relaying. The asymptotic analysis for the SOP is also conducted to provide more insights on the impact of FSO and satellite channels on secrecy performance. It is found that with the AF with fixed gain scheme, the secrecy diversity order of the investigated system is only dependent on the channel characteristics of the FSO link and the FSO detection type, whereas the secrecy diversity is zero when the relay node employs DF or AF with variable-gain schemes.
关键词： land mobile satellite (LMS) channel,secrecy outage probability,hybrid satellite free-space optical (FSO) cooperative system,Physical layer security,average secrecy capacity
更新于2025-09-23 15:22:29
-
-Distribution Dual-Hop RF/FSO Systems
摘要： In this correspondence, we investigate the physical-layer security of a mixed radio frequency/free space optical (RF/FSO) dual-hop communication system for both fixed- and variable-gain relaying schemes. More specifically, we only assume that the eavesdropping happens at the RF link because the optical link has high security. We assume that all RF channels suffer from η–μ fading, while the FSO link experiences M-distributed fading. Then, we derive some analytical results for the average secrecy rate and the secrecy outage probability.
关键词： secrecy outage probability,Average secrecy rate,radio frequency-free space optical,M-distributed fading,η-μ fading,physical-layer security
更新于2025-09-23 15:22:29
-
Performance Investigate and Analysis of 96?×?10 Gbps DWDM System Using Suitable Rating from Optical Amplifiers
摘要： The objective of current work is to design and analyzed 96 × 10 Gbps DWDM system taking EDFA, SOA, and RAMAN amplifier as an inline amplifiers up to a fiber length of 300 km. The performance of EDFA, SOA, and RAMAN amplifier is measured on the basis of power received, Q-factor, probability of error and BER for various values of fiber distance. In this paper it has been proved that for 96 channels DWDM system at 10 Gbps bit rate, EDFA reveals superior performance as far as the amount of power received is concerned. The value of quality factor (Q-factor) for RAMAN amplifier is almost identical to that of the Q-factor for EDFA and is higher than the Q-factor for SOA till a fiber length of roughly 80 km thereafter SOA reveals somewhat better Q-factor than EDFA and RAMAN amplifier. As far as BER is concerned EDFA and RAMAN amplifier show roughly identical and somewhat lower BER than SOA till a fiber length of roughly 80 km, afterwards SOA reveal somewhat lesser BER till the fiber length of 210 km. In relation to the probability of error P(E), It is analyzed that P(E) remains more or less same for the entire set of optical amplifiers (OAs) but beyond the fiber length of 240 km EDFA shows somewhat lower P(E) than the other two OAs. At the end the Eye diagrams for the three OAs are also figure out.
关键词： BER,DWDM,probability of error P(E),RAMAN amplifier,EDFA,SOA
更新于2025-09-23 15:22:29
-
Energy Harvesting Wireless Communications || Power Allocation for Point-to-Point Energy Harvesting Channels
摘要： This chapter considers a point-to-point EH wireless channel when the transmitter and the receiver are powered by EH. Under this setup, we first maximize various system utilities (such as the end-to-end throughput and the non-outage probability) via adaptive power allocation over time subject to the EH constraints at the transmitter, where the accumulatively consumed energy should not exceed that accumulatively harvested at any time. Under various CSIT and ESIT assumptions, we discuss the respective optimal designs. For example, in the noncausal CSIT and ESIT case, the optimal offline power allocation is shown to follow a non-decreasing and piecewise-constant (or staircase-like) pattern for the Gaussian channel case, and the optimal transmit power corresponds to a staircase water-filling power allocation for the fading channel case. In the causal ESIT and CSIT case, applicable online optimization strategies include dynamic programming-based and heuristically designed power allocation strategies. We also point out several open problems under different ESIT and CSIT considerations. For example, the throughput maximization problems under the case with causal CSIT and noncausal ESIT and the case with no CSIT and noncausal/causal ESIT remain unsolved in general, while the outage probability minimization problems under causal CSIT and noncausal/causal ESIT are also open problems at large. Furthermore, we extend the power allocation policies to other scenarios by considering other practical constraints such as limited battery capacity and imperfect circuits. We show that in the noncausal CSIT and ESIT case, the staircase power allocation with Gaussian channel and the staircase water-filling power allocation with fading channels can be modified to take these new practical constraints into account. With imperfect circuits, the EH transmitter should employ an on-off power allocation, which turns the transmitter into a sleep mode to save power in order to transmit more energy efficiently in the wake-up mode to tradeoff between the transmit energy consumption versus the circuit energy consumption. These new offline power allocation strategies motivate new online power allocation approaches with only causal CSIT and ESIT. Finally, we provide discussions on the transmit and receive power allocations in the case with EH transmitter and EH receiver, where in addition to the transmitter, the receiver's power consumption is also subject to an EH constraint. Under such a scenario, it is essential for the transmitter and the receiver to jointly optimize the transmit power and the code rate (hence, control the receive power consumption) to improve the end-to-end utility. Note that the case of EH receiver has not been widely investigated in the literature and there are rich open problems (e.g. under causal CSIT and ESIT) worth being pursued in future work.
关键词： power allocation,outage probability minimization,battery capacity,EH receiver,imperfect circuits,ESIT,wireless communications,throughput maximization,CSIT,Energy harvesting
更新于2025-09-23 15:22:29
-
Impact of Random Receiver Orientation on Visible Light Communications Channel
摘要： Visible Light Communications (VLC) has been studied thoroughly in recent years as an alternative or complementary technology to radio frequency communications. The reliability of VLC channels highly depends on the availability and alignment of line of sight links. In this work, we study the effect of random receiver orientation for mobile users over VLC downlink channels, which affects the existence and quality of line of sight links. Based on the statistics of the receiver location and relative orientation with respect to the transmitter LED, we develop an analytical framework to characterize the statistical distribution of VLC downlink channels, which is then utilized to obtain the outage probability and the bit error rate. Our analysis is generalized for arbitrary distributions of relative orientation and location for a single transmitter, and extended to multiple transmitter case for some certain scenarios. Extensive Monte Carlo simulations show a perfect match between the analytical and the simulation data in terms of both the statistical channel distribution and the resulting bit error rate. Our results also characterize the channel attenuation due to random receiver orientation and location for various scenarios of interest.
关键词： probability,random variables,Light-emitting diodes,optical communication,light-fidelity (Li-Fi)
更新于2025-09-23 15:21:21