The present disclosure generally relates to techniques for processing complex-valued array data representing an image. The techniques may include obtaining an electronic representation of an array of complex numbers representing an image, converting the array of complex numbers to an array of scaled coordinate pair values in a magnitude-phase plane, replacing each coordinate pair value with data representing a respective nearest node in a quantized magnitude-phase plane, such that an array of scaled quantized coordinate value pairs is produced, arranging into a sequence of bit values ordered according to decreasing bit significance, from most-significant bit values to least-significant bit values, the scaled quantized coordinate value pairs, and transmitting the sequence of bit values to a receiver, such that the receiver rearranges and rescales the sequence of bit values and obtains the image represented by the array of complex numbers.

Various embodiments of the present technology generally relate to systems, methods, and computer-readable media for simulating synthetic aperture radar (SAR) images to be captured by a radar-based imaging system. SAR technology can be used to capture large areas on Earth, from a satellite in space for example, over a single pass. A further pass over the target area can help identify changes in the landscape, scenery, and/or infrastructure providing insight on change detection, temporal analysis, or other measures; however, repeat passes over the target area may have been made from differing angles resulting in artifacts in one or both of the processed images from the two passes. In various embodiments, information about the topology of the target area, and information about the SAR platform's flight path are used to simulate the slant range distortion effects that are to be expected in the SAR image of for that pass.

A temperature compensation method for a SAR sensor (3) of a terminal, and a terminal are disclosed. The terminal comprises: a temperature sensing unit (1), a processor (2), and an SAR sensor (3); the temperature sensing unit (1) is configured to send a first trigger signal to the processor (2) in response to detecting that a temperature change amount of the SAR sensor (3) exceeds a preset value; the processor (2) is configured to send a first temperature control signal to the SAR sensor (3) upon receiving the first trigger signal; and the SAR sensor (3) is configured to activate a second-order temperature compensation of the SAR sensor (3) according to the first temperature control signal, and the second-order temperature compensation compensates for baseline data of the SAR sensor (3) together with a first-order temperature compensation of the SAR sensor (3). Therefore, real-time tracking of the temperature change amount by the baseline data of the SAR sensor (3) can be ensured, and the problem in the terminal of false trigger of the SAR sensor (3) caused by drastic temperature change can be avoided.

Described is a stripmap SAR system on a vehicle comprising an antenna that is fixed and directed outward from the side of the vehicle, a SAR sensor, a storage, and a computing device. The computing device comprises a memory, one or more processing units, and a machine-readable medium on the memory. The machine-readable medium stores instructions that, when executed by the one or more processing units, cause the stripmap SAR system to perform various operations. The operations comprise: receiving stripmap range profile data associated with observed views of a scene; transforming the received stripmap range profile data into partial circular range profile data; comparing the partial circular range profile data to a template range profile data of the scene; and estimating registration parameters associated with the partial circular range profile data relative to the template range profile data to determine a deviation from the template range profile data.

A method for using Synthetic Aperture Radar (SAR) to perform a maneuver in a land vehicle is provided. The method includes: receiving digitized radar return data from a radar transmission from a SAR onboard the vehicle; accumulating a plurality of frames of the digitized radar return data; applying a RADON transform to the accumulated plurality of frames of the digitized radar return data and odometry data from the vehicle to generate transformed frames of data for each three-dimensional point, wherein the RADON transform is configured to perform coherent integration for each three-dimensional point, project a radar trajectory onto each three-dimensional point, and project Doppler information onto each three-dimensional point; generating a two-dimensional map of an area covered by the radar transmission from the SAR based on the transformed frames of data for each three-dimensional point; and performing a maneuver with the land vehicle by applying the generated two-dimensional map.

A method for using Synthetic Aperture Radar (SAR) to perform a maneuver in a land vehicle is provided. The method includes: receiving digitized radar return data from a radar transmission from a SAR onboard the vehicle; accumulating a plurality of frames of the digitized radar return data; applying a RADON transform to the accumulated plurality of frames of the digitized radar return data and odometry data from the vehicle to generate transformed frames of data for each three-dimensional point, wherein the RADON transform is configured to perform coherent integration for each three-dimensional point, project a radar trajectory onto each three-dimensional point, and project Doppler information onto each three-dimensional point; generating a two-dimensional map of an area covered by the radar transmission from the SAR based on the transformed frames of data for each three-dimensional point; and performing a maneuver with the land vehicle by applying the generated two-dimensional map.

The present invention provides an apparatus for compensating a phase error of an RF band chirp signal by pre-distorting a base band chirp signal, including: a waveform generator to output the base band chirp signal; an RF modulator to output the RF band chirp signal by upconverting the base band chirp signal; an error calculation unit to calculate a phase error over time for a predetermined time by comparing the RF band chirp signal with an ideal chirp signal; a section division unit to divide the predetermined time into a plurality of time sections; a section combination unit to combine neighboring time sections based on the phase error; and a phase distortion unit to distort phase of the base band chirp signal in the combined time sections based on the phase error.

A learning data generation device includes: a target object image generating unit for simulating radar irradiation to a target object using a 3D model of the target object to generate a target object-simulated radar image that is a simulated radar image of the target object; a background image acquiring unit for acquiring a background image using radar image information generated by the radar device performing radar irradiation; an image combining unit for generating a combined pseudo radar image obtained by combining the background image and the target object-simulated radar image by pasting the target object-simulated radar image generated by the target object image generating unit to a predetermined position in the background image acquired by the background image acquiring unit; and a learning data generating unit for generating learning data that associates combined simulated radar image information indicating the combined pseudo radar image generated by the image combining unit with class information indicating a type of the target object.

The present invention provides an apparatus for compensating a phase error of an RF band chirp signal by pre-distorting a base band chirp signal, including: a waveform generator to output the base band chirp signal; an RF modulator to output the RF band chirp signal by upconverting the base band chirp signal; an error calculation unit to calculate a phase error over time for a predetermined time by comparing the RF band chirp signal with an ideal chirp signal; a section division unit to divide the predetermined time into a plurality of time sections; a section combination unit to combine neighboring time sections based on the phase error; and a phase distortion unit to distort phase of the base band chirp signal in the combined time sections based on the phase error.

Described is a stripmap SAR system on a vehicle comprising an antenna that is fixed and directed outward from the side of the vehicle, a SAR sensor, a storage, and a computing device. The computing device comprises a memory, one or more processing units, and a machine-readable medium on the memory. The machine-readable medium stores instructions that, when executed by the one or more processing units, cause the stripmap SAR system to perform various operations. The operations comprise: receiving stripmap range profile data associated with observed views of a scene; transforming the received stripmap range profile data into partial circular range profile data; comparing the partial circular range profile data to a template range profile data of the scene; and estimating registration parameters associated with the partial circular range profile data relative to the template range profile data to determine a deviation from the template range profile data.