Abstract: The present disclosure provides a cross-correlation based method, a system and a storage medium for blind electromagnetic interference Doppler estimation from a single satellite geolocation system. The method includes at a first time, calculating a power spectral density (PSD) of a received signal; smoothing the PSD of the received signal using moving window average, and saving the smoothed PSD of the received signal as PSD0; at a next time, calculating a PSD of another received signal; smoothing the PSD of the another received signal using moving window average, and saving the smoothed PSD of the another received signal as PSD1; performing cross correlation between PSD0 and PSD1 to obtain a cross-correlation result; determining a peak position from the cross-correlation result; and obtaining a Doppler estimation based on a peak position shift between the peak position and a reference position.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for generating a variable quality clock signal to preserve power for electronic devices. According to one aspect, there is provided a system that includes (i) a stand-by clock, configured to produce a stand-by clock signal when the system is in a low-power mode, and (ii) a primary clock, configured to produce a primary clock signal when the system is in an active mode, with the system configured to switch from the low-power mode to the active mode by providing the output of the stand-by clock as a start-up signal to the primary clock.

Abstract: A method for recognizing a low-probability-of-interception (LPI) radar signal waveform includes: obtaining, by a radar signal receiver, an LPI radar signal s(t), s(t) varying with time t; extracting, by a radar signal processor, an adaptive feature and a pre-defined analytical feature from the LPI radar signal s(t); combining, by the radar signal processor, the adaptive feature with the pre-defined analytical feature to generate a constructed adaptive feature; and applying, by the radar signal processor, a convolutional neural network (CNN) model to classify the constructed adaptive feature to recognize the LPI radar signal waveform.

Abstract: A method for detecting GPS spoofing attacks includes providing a trained deep learning (DL) model based on neural networks, feeding GPS signals into the trained DL model, using asymmetric Shapley values (ASVs) to calculate feature contributions, using the ASVs to assign a non-uniform distribution over an ordering of features, obtaining causal structures among the features, applying the ASVs to causal Shapley additive explanation to obtain Shapley attributions, incorporating the Shapley attributions and the causal structures, and detecting GPS spoofing attacks by running the trained DL model and using the causal structures, non-uniform distribution, feature contributions, and Shapley attributions.

Abstract: Embodiments of the present disclosure provide a method, a device, and a storage medium for domain adaptation for efficient learning fusion (DAELF). The method includes acquiring data from a plurality of data sources of a plurality of sensors; for each of the plurality of sensors, training an auxiliary classifier generative adversarial network (AC-GAN) by a hardware processor with data from each data source of the plurality of data sources, thereby obtaining a trained feature extraction network and a trained label prediction network for each data source; forming a decision-level fusion network or a feature-level fusion network; and training the decision-level fusion network or the feature-level fusion network with a source-only mode or a generate to adapt (GTA) mode; and applying the trained decision-level fusion network or the trained feature-level fusion network to detect a target of interest.

Abstract: The present disclosure provides a method, a system and a storage medium of PID-based automatic gain control for a satellite transponder system. The method includes receiving a sequence of sample signals; determining two different block sizes where a block size of a first block is greater than a block size of a second block; using the block size of the first block to compute a first signal-amplitude-ratio (SAR)-based gain value and using the block size of the second block to compute a second signal-amplitude-ratio (SAR)-based gain value by the AGC processor through the sequence of sample signals; calculating a to-be-applied gain control value of an m-th transmitted symbol at a n-th time step; and calculating a new AGC gain at the n-th time step according to the to-be-applied gain control value at the n-th time step and a corresponding AGC gain at the (n?1)-th time step.

Abstract: The present disclosure provides a method, a system and a storage medium of PID-based automatic gain control for a satellite transponder system. The method includes receiving a sequence of sample signals; determining two different block sizes where a block size of a first block is greater than a block size of a second block; using the block size of the first block to compute a first signal-amplitude-ratio (SAR)-based gain value and using the block size of the second block to compute a second signal-amplitude-ratio (SAR)-based gain value by the AGC processor through the sequence of sample signals; calculating a to-be-applied gain control value of an m-th transmitted symbol at a n-th time step; and calculating a new AGC gain at the n-th time step according to the to-be-applied gain control value at the n-th time step and a corresponding AGC gain at the (n?1)-th time step.

Abstract: The present disclosure provides a method for model predictive automatic gain control under additive white Gaussian noise jamming. The method includes predicting a plurality of consecutive signal values by an autoregressive integrated moving average model; calculating a signal average value of the plurality of consecutive signal values; calculating a gain control value using the signal average value of the plurality of consecutive signal values; if the gain control value is greater than a maximum control capability of a AGC processor, using the gain control value as a desired gain control value; or if the gain control value is equal to or less than the maximum control capability, using a minimum difference between an estimated amplitude and each of reference amplitudes in the LUT as the desired gain control value; and calculating a new AGC gain for a current time step according to the desired gain control value.

Abstract: The present disclosure provides a method, a system and a storage medium of resilient human-on-the-loop range-only cooperative positioning of a plurality of unmanned aerial vehicles (UAVs). The method includes computing an initial exploitability using an initial distribution and an initial policy; performing a forward updating of a distribution of a portion of the plurality of UAVs, and performing a backward updating of a Q function of each UAV of the plurality of UAVs; for each time step, calculating a dual variable at an (i+1)-th iteration and calculating a policy at an (i+1)-th iteration; computing a ratio of an exploitability at the (i+1)-th iteration over the initial exploitability; and if the ratio is less than or equal to a pre-defined tolerance value, maintaining a policy at the i-th iteration; and if the ratio is greater than the pre-defined tolerance value, using the policy at the (i+1)-th iteration.

Abstract: Methods, apparatus, and systems to determine a niche market of items or services, the first phase of which identifies a gap between demand and supply for a set of items. Session logs may be evaluated to compare transactions involving a specific item to those of a larger group of items. The resultant information identifies areas of high demand, but with low availability. The niche market information may be provided as direct merchandising items for sellers. In one example, the method generates niche market item web pages in specific categories. Additional methods, apparatus, and systems are disclosed.

Abstract: A method for recognizing a low-probability-of-interception (LPI) radar signal waveform includes: obtaining, by a radar signal receiver, an LPI radar signal s(t), s(t) varying with time t; extracting, by a radar signal processor, an adaptive feature and a pre-defined analytical feature from the LPI radar signal s(t); combining, by the radar signal processor, the adaptive feature with the pre-defined analytical feature to generate a constructed adaptive feature; and applying, by the radar signal processor, a convolutional neural network (CNN) model to classify the constructed adaptive feature to recognize the LPI radar signal waveform.

Abstract: The embodiments of the present application disclose an emitter, an emitting module, and a LiDAR. The emitter includes a laser, a driving circuit, a substrate, and a heat conduction member. The laser and the driving circuit are both mounted on the substrate, and the heat conduction member is connected to the substrate, with at least the portion of the substrate used for mounting the laser being in contact with the heat conduction member. Mounting the laser on the substrate and having at least the portion of the substrate used for mounting the laser in contact with the heat conduction member facilitates timely and efficient heat dissipation from the laser through the heat conduction member, improving the heat dissipation rate around the laser and avoiding local hot spots at the laser, thereby ensuring the normal operation of the laser.

Abstract: Methods, apparatus, and systems to determine a niche market of items or services, the first phase of which identifies a gap between demand and supply for a set of items. Session logs may be evaluated to compare transactions involving a specific item to those of a larger group of items. The resultant information identifies areas of high demand, but with low availability. The niche market information may be provided as direct merchandising items for sellers. In one example, the method generates niche market item web pages in specific categories. Additional methods, apparatus, and systems are disclosed.

Abstract: Embodiments of the present disclosure provide a method, a device, and a storage medium for hybrid automatic gain control in a communication system. The method includes amplifying an input signal to generate an amplified signal which is converted into a plurality of output signals; obtaining a moving average amplitude of a plurality of output signals of a current input signal; and calculating a signal amplitude difference according to the moving average amplitude and a desired output signal amplitude level; calculating a signal amplitude ratio according to a plurality of output signals of two previous output signal blocks and AGC gains corresponding to the plurality of output signals of the two previous output signal blocks; obtaining a step size according to the signal amplitude difference and the signal amplitude ratio; and calculating an AGC gain of the current input signal according to the step size and a corresponding previous AGC gain.

Abstract: The present disclosure provides a method, a device, and a storage medium for decentralized optimal control for a large-scale multi-agent system. The method includes initializing errors to obtain an initialized error of each of an actor NN, a critic NN and a mass NN; initializing error thresholds to obtain an initialized error threshold of each of the actor NN, the critic NN and the mass NN; and if the initialized error of each of the actor NN, the critic NN and the mass NN is greater than or equal to a corresponding initialized error threshold, calculating weights of each of the actor NN, the critic NN and the mass NN, and updating the actor NN, the critic NN, and the mass NN; and calculating errors of each of the actor NN, the critic NN and the mass NN, and updating the actor NN, the critic NN, and the mass NN.

Abstract: The present disclosure provides a cross-correlation based method, a system and a storage medium for blind electromagnetic interference Doppler estimation from a single satellite geolocation system. The method includes at a first time, calculating a power spectral density (PSD) of a received signal; smoothing the PSD of the received signal using moving window average, and saving the smoothed PSD of the received signal as PSD0; at a next time, calculating a PSD of another received signal; smoothing the PSD of the another received signal using moving window average, and saving the smoothed PSD of the another received signal as PSD1; performing cross correlation between PSD0 and PSD1 to obtain a cross-correlation result; determining a peak position from the cross-correlation result; and obtaining a Doppler estimation based on a peak position shift between the peak position and a reference position.

Abstract: The present disclosure provides a method for decentralized optimal control for passive SSG of ground-based EMI sources. The method includes simulating a scenario based on an EMI source and a satellite specified by a TLE file; and calculating positions, velocities and accelerations of the satellite at different time indexes of the simulated scenario; calculating Doppler shifts and Doppler rates according to the positions, the velocities and the accelerations of the satellite at the different time indexes; and implementing a constrained unscented Kalman filter (cUKF) based on the Doppler shifts and the Doppler rates to obtain an updated state; and calculating a recursive constrained posterior Cramér-Rao bound (rcPCRB); and fine tuning the cUKF using the calculated rcPCRB to obtain an updated cUKF.

Abstract: A global navigation satellite system (GNSS) is disclosed comprising a transmitter. The transmitter is configured to: receive a plurality of frequencies; determine a minimum frequency from the plurality of frequencies; determine a maximum frequency from the plurality of frequencies; determine a carrier from the minimum frequency and the maximum frequency; determine a set of subcarriers from the carrier and the plurality of frequencies; identify optimal radius of desired phase points to select optimal subcarriers from the set of subcarriers; determine inter-modulation terms with a minimal energy based on the optimal subcarriers; and generate multi-carrier constant envelope waveforms based on the inter-modulation terms.

Abstract: A battery module includes a first guard and a plurality of battery cells. The plurality of battery cells are arranged along a first direction. One end of the battery cell in a second direction is provided with a pressure relief mechanism. The second direction is perpendicular to the first direction. The pressure relief mechanism is configured to release the internal pressure of the battery cell when the internal pressure or temperature of the battery cell reaches a threshold value. The first guard includes a first guarding portion covering the end of the plurality of battery cells provided with the pressure relief mechanism. A plurality of venting ports are provided on the first guarding portion, and the venting port and the pressure relief mechanism are provided in a staggered manner in the second direction.

Abstract: A system and method are provided for enhanced multi-way time transfer for time synchronization between at least one slave node and one master node. A slave node sends a first message to the master node to launch a time synchronization between the slave node and the master node. Upon receiving the first message, the master node adds a receiving time on a master clock to the first message to form a second message. The master node sends the second message back to the slave node and the slave node adds a receiving time on the slave clock to the second message to form an updated message. The slave node performs a time adjustment to the slave clock based on the updated message, thereby synchronizing time between the slave node and the master node.