Abstract: An azimuth ambiguity suppression method for a spaceborne SAR in spatially non-uniform sampling relates to the technical field of radars. The method includes the following steps: step 1: compensating for a phase difference between the channels according to the locations of transmitting and receiving stations for channel echoes; step 2: calculating an equivalent azimuth sampling location of each channel at the moment of each pulse transmission; step 3: sorting the equivalent azimuth sampling locations of all channels and their corresponding echoes after the phase difference between the channels is compensated in ascending order; and step 4: calculating reconstructed echoes from the sorted equivalent azimuth sampling locations and corresponding echoes after the phase difference between the channels is compensated, by using an adaptive weight-conjugate gradient-Toeplitz matrix (ACT) algorithm.

Abstract: The present disclosure discloses a method for suppressing the azimuth ambiguity of multi-channel SAR systems based on channel cancellation, which falls within the field of radar signal processing. The method includes: imaging echoed of the multi-channel SAR system based on a linear mapping reconstruction algorithm to obtain a reconstructed high-resolution wide-swath image; estimating positions of the azimuth ambiguity regions of the reconstructed high-resolution wide-swath image; extracting ambiguity images in the azimuth ambiguity regions based on channel cancellation and the refocusing algorithm; and suppressing a repetitive ambiguity image in imaging the echo of the multi-channel SAR system.

Abstract: An optical satellite remote sensing transfer calibration method based on near-space aerostat, including: performing a temporal-spatial matching between first observation image data of a target region collected by a benchmark radiometric payload and second observation image data of the target region collected by a satellite-borne payload, to obtain a plurality of matchups of observation image data (S1); obtaining an average radiance of the benchmark radiometric payload from a plurality of first observation image data (S2); obtaining an average DN captured by the satellite payload in the target region from a plurality of second observation image data (S3); obtaining a matching radiance for an observation band of the benchmark radiometric payload corresponding to the satellite payload based on the average radiance of the benchmark radiometric payload (S4); and obtaining a calibration coefficient of the satellite payload based on the matching radiance and the average DN (S5).

Abstract: A method for extracting an oil storage tank based on a high-spatial-resolution remote sensing image is provided, including: acquiring an oil storage tank sample, and randomly dividing the oil storage tank sample into a training set and a testing set; building an oil storage tank extraction model based on a Res2-Unet model structure, wherein the Res2-Unet is a deep learning network based on a UNet semantic segmentation structure, and a Res2Net convolution block is configured to change a feature interlayer learning to a granular learning and is arranged in a residual mode; and performing a precision verification on the testing set.

Abstract: A terahertz carrier-envelope phase shifter includes a substrate, a first phase modulator and a second phase modulator, which are arranged on a surface of the substrate. The first phase modulator has a first phase modulation angle. The second phase modulator has a second phase modulation angle that is different from the first phase modulation angle. A carrier-envelope phase of a terahertz pulse after the terahertz pulse passes through the first phase modulator and the substrate is different from a carrier-envelope phase of the terahertz pulse after the terahertz pulse passes through the second phase modulator and the substrate. By means of the simple displacement, a terahertz pulse can pass through different phase modulators to obtain the required carrier-envelope phases. A geometric parameter and the spatial position of a microstructure in the first or the second phase modulator are changed and the carrier-envelope phases of the terahertz pulse covers 0-2 ?.

Abstract: A method and a device for a predicting desert locust are provided. The method includes: acquiring environment factor data of a target area, where the environment factor data includes total precipitation data, soil temperature data, soil water data, and vegetation index data; extracting fluctuation features corresponding to the environment factor data through wavelet transform, where the fluctuation features include a precipitation fluctuation feature corresponding to the total precipitation data, a soil temperature fluctuation feature corresponding to the soil temperature data, a soil water fluctuation feature corresponding to the soil water data, and a vegetation fluctuation feature corresponding to the vegetation index data; and predicting time when the desert locust presents in the target area based on the fluctuation features.

Abstract: A method and an apparatus were disclosed for measuring wood density of live timber. The method comprising: measuring a diameter of a test part of the live timber at a first height from a ground surface; transmitting and receiving microwave in a preset frequency range in air at a first distance greater than the diameter, measuring a first ratio of a transmitted microwave signal to a first received microwave signal at different frequencies; transmitting microwave in the air at the first height and microwave penetrates the test part, receiving the microwave at the first distance from the microwave transmitting position, measuring a second ratio of a transmitted microwave signal to a second received microwave signal at different frequencies, calculating a dielectric constant and an attenuation constant; calculating the wood density according to a relationship between the wood density and the dielectric constant and the attenuation constant.

Abstract: An optical satellite remote sensing transfer calibration method based on near-space aerostat, including: performing a temporal-spatial matching between first observation image data of a target region collected by a benchmark radiometric payload and second observation image data of the target region collected by a satellite-borne payload, to obtain a plurality of matchups of observation image data (S1); obtaining an average radiance of the benchmark radiometric payload from a plurality of first observation image data (S2); obtaining an average DN captured by the satellite payload in the target region from a plurality of second observation image data (S3); obtaining a matching radiance for an observation band of the benchmark radiometric payload corresponding to the satellite payload based on the average radiance of the benchmark radiometric payload (S4); and obtaining a calibration coefficient of the satellite payload based on the matching radiance and the average DN (S5).

Abstract: A system and a method are provided. The system includes an airborne detection system and a ground assistance system. The airborne detection system includes an unmanned aerial vehicle, a receiving device, a transmitting device, and a connecting device. The transmitting device includes a transmitting sub-device, a transmitting coil, and a bucking coil. The receiving device includes a receiving sub-device and a three-component magnetic sensor. The connecting device includes a signal and rope composite cable and is used to connect the UAV, the transmitting device, and the receiving device. The three-component magnetic sensor is used to acquire three-component electromagnetic data. The bucking coil is disposed on an inner side of the transmitting coil, and coil winding direction of the transmitting coil and the bucking coil causes current directions flowing through the transmitting coil and the bucking coil to be opposite to each other, to reduce an electromagnetic interference.

Abstract: A stability control method and device based on particle active disturbance rejection are provided. The method includes: establishing an active disturbance rejection controller model based on a dynamic model and a speed loop control model of a tethered balloon system, where the speed loop control model is established through theoretical modeling of executive components of a control system of the tethered balloon system; and optimizing to-be-optimized parameters of the active disturbance rejection controller model using a particle swarm optimization algorithm, determining an optimal active disturbance rejection controller model, and using the optimal active disturbance rejection controller model to implement stability control of a photoelectric pod. An active disturbance rejection controller is optimized by using a particle swarm optimization algorithm, which can effectively isolate the internal and external disturbances of the photoelectric pod and improve the imaging stability of the photoelectric pod.

Abstract: The present disclosure discloses an extraction method of raft culture area based on multi-temporal optical remote sensing images, including: constructing a raft culture marker sample library including culture types such as fish, shellfish, and algae; optimizing the deep learning model of the UNet network by using ASPP (Atrous Spatial Pyramid Pooling) and the shape constraint module; using the deep learning model to extract a corresponding multi-temporal raft culture area by using the multi-temporal optical remote sensing images with medium resolution in the target area; combining prior knowledge, fusing the extraction results of the raft culture area to obtain a final extraction results of the raft culture area.

Abstract: This invention discloses a practical method for landslide detection in large space, which comprises the following steps: image synthesis, ice and snow detection, removal of non-potential landslide area, detection of potential landslide area, feature calculation, landslide detection model construction and precision validation; this invention avoids radiometric correction and outlier by detecting landslide from synthetic image. That guarantees practical applicability of the proposal. Firstly, detecting potential landslides can avoid the imbalanced sample distribution issue between background objects and landslides when training the landslide detection model. The landslide is further detected by building a random forest model based on the spectral features and textural features of potential landslide pixels in different neighboring time domains. It fully considers the changes of objects in different time domains, and lays a foundation for efficient landslide extraction.

Abstract: A magnetic compensation method based on an aeromagnetic compensation error model includes: acquiring an upper limit of an error of a magnetic noise caused by both an environmental background field in an exploration area and an aeromagnetic flight platform, by using the aeromagnetic compensation error model, before an actual flight; determining, according to the upper limit, whether the environmental background field and the aeromagnetic flight platform are suitable for the actual flight, and if so, performing a calibration flight to acquire a compensation coefficient; and acquiring data of an attitude term by performing the actual flight, calculating an interference magnetic field by the data of the attitude term and the compensation coefficient, and performing magnetic compensation.

Abstract: A method for extracting an oil storage tank based on a high-spatial-resolution remote sensing image is provided, including: acquiring an oil storage tank sample, and randomly dividing the oil storage tank sample into a training set and a testing set; building an oil storage tank extraction model based on a Res2-Unet model structure, wherein the Res2-Unet is a deep learning network based on a UNet semantic segmentation structure, and a Res2Net convolution block is configured to change a feature interlayer learning to a granular learning and is arranged in a residual mode; and performing a precision verification on the testing set.

Abstract: A method for soil moisture retrieval using multi-channel collaboration algorithm and passive microwave radiometry including: establishing mathematical relationship formula between brightness temperatures at any two channels according to microwave radiative transfer equation; collecting actual brightness temperatures of core channel and collaborative channels; selecting parameters to be retrieved including soil moisture value; giving a series of estimated values of parameters to be retrieved, calculating a series of predicted brightness temperatures of collaborative channels according to actual brightness temperature of core channel, microwave radiative transfer equation and mathematical relationship formula, comparing predicted brightness temperatures with actual brightness temperature, and determining soil moisture value.

Abstract: A system for numerical simulation and test verification of icing characteristics of an aerostat includes an aerostat icing characteristic calculation model and an aerostat icing characteristic test system. The aerostat icing characteristic calculation model is configured to obtain icing data of the aerostat through numerical simulation, and the aerostat icing characteristic test system is configured to obtain icing characteristic data of the aerostat through a physical simulation test. The calculation result obtained through the numerical simulation and the test result obtained through the physical simulation test are mutually verified and improved, so as to facilitate the in-depth research and accurate analysis of the icing characteristics of the aerostat.

Abstract: A system for numerical simulation and test verification of icing characteristics of an aerostat includes an aerostat icing characteristic calculation model and an aerostat icing characteristic test system. The aerostat icing characteristic calculation model is configured to obtain icing data of the aerostat through numerical simulation, and the aerostat icing characteristic test system is configured to obtain icing characteristic data of the aerostat through a physical simulation test. The calculation result obtained through the numerical simulation and the test result obtained through the physical simulation test are mutually verified and improved, so as to facilitate the in-depth research and accurate analysis of the icing characteristics of the aerostat.