Airborne systems and methods for the detection, location and obtaining of images of buried objects and for the characterization of the composition of the subsoil. The systems comprise at least one aerial module with a radar unit that emits and/or captures radar signals and a positioning and guidance system with an accuracy equal to or less than 3 cm, and a ground station with a flight control system and a radar signal processing unit where radar signal processing algorithms are applied. The invention also comprises a method for the detection, localization and obtaining of images of buried objects and a method for the characterization of the composition of the subsoil. Applicable in sectors where it is necessary to perform the detection of buried objects, as for example in civil applications (detection of antipersonnel mines), pipeline inspection or in archaeology.

Systems and methods in accordance with various embodiments of the present disclosure provide high efficiency synthetic aperture radar satellite designs that achieve higher power efficiency and higher antenna aperture size to satellite mass ratios than the current state of the art. In various embodiments, a high efficiency synthetic aperture radar satellite includes a satellite bus and a parabolic reflector antenna coupled to the satellite bus. The satellite system may further include a traveling wave tube amplifier configured to drive the parabolic reflector antenna, and a body-mounted steering system configured to mechanically steer the satellite system to direct the parabolic reflector antenna. The satellite system may further include a processor configured to combine the pulse reflections and generate image data representing the region of interest, in which the image data is effectively obtained with a synthetic aperture greater than the actual antenna aperture.

A microwave and millimeter wave imaging system. In either a far-field or a near-field detection mode, a radially-polarized probe transmits an imaging signal along a predetermined scan path to detect a target in a sample. The imaging signal's orientation is independent of the target's orientation and changes at each target as the probe transmits the signal during scanning. A measurement system receives scattered waves reflected from the sample via a single channel and images the sample and the target based on the reflected waves independent of the orientation of the target.

A quad-pol synthetic aperture radar (SAR) system reduces the effects of range ambiguities in a quad-pol SAR data. Pulses are transmitted in two sub-bands at respective ones of two different linear orientations. For each sub-band and orientation, returns are received in two orientations, and filtered to attenuate the other sub-band. A scattering matrix may be determined from the results. Additionally or alternatively, a Faraday rotation angle associated with acquired quad-pol SAR data is estimated, and used to correct a scattering matrix. Estimation may occur before, after, or both before and after acquisition of the quad-pol SAR data.

X-band and P-band synthetic aperture radars are used to simultaneously gather swaths of reflected radar data over a specific area simultaneously. The P-band is used to penetrate surface clutter that may be on the top of an ice formation as well as to penetrate an ice mass. X-band is used to map surface clutter on the top of an ice formation as well as to map the top of snow that may appear on an ice formation. Digital elevation maps of the top of the snow or ice clutter, the top of the ice, and the bottom of the ice and or ice thickness are constructed. By summing these various digital elevation maps a measurement of the thickness of sea ice can be determined. Further analysis of DEM, MAG and CRV layers provides an indication of the quality of the ice, for example cracks and pressure ridges, and its weak points.

In an approach to improve detecting and identifying objects through orbital synthetic aperture radar satellites, embodiments arrange an array of elements in a predetermined configuration, and process, by a threshold and signature analysis, detected peaks in processed image data. Further, embodiments generate a list of objects detections based on the processed peaks, and identify an object based on amplitude, polarization ratio, and polarization phase difference. Additionally, embodiments, classify the identified object based on the generated list of objects, and output, by a user interface, a list of probable object detections with position coordinates and identifications based on the classified identified objects, wherein the list of probable objects are above or within a predetermine threshold of confidence.

Synthetic aperture radar (SAR) imaging systems that transmit repeated waveforms based upon pseudonoise sequences to generate SAR imaging data in accordance with various embodiments of the invention are disclosed. A synthetic aperture radar in accordance with one embodiment of the invention includes: a transmitter configured to transmit superchirps, where the superchirp is generated by convolving a kernel with a pseudonoise modulated impulse sequence having a flat power spectrum; a receiver configured to receive backscatters of transmitted superchirps and digitize the received backscatters; and signal processing circuitry configured to perform matched filtering on digitized backscatters.

A digital beamforming synthetic aperture radar (SAR) mixes a first analog signal to generate a frequency-shifted first signal having a first spectral band, mixes a second analog signal to generate a frequency-shifted second signal having a second spectral band, positioned at a defined frequency offset from the first spectral band, and positioned non-overlapping relation with the first spectral band, combines the first and second frequency-shifted signals to generate a combined analog receive signal, and band-pass samples the combined analog receive signal to generate a digital baseband signal representative of the first and second analog signals. The SAR may mix the second analog signal to position the second spectral band in the Nyquist bandwidth, and in non-overlapping relationship with the first spectral band. Mixing may include down converting the analog signal.

Embodiments of the invention are directed to a method of determining underground liquid content (e.g., water, sewage, etc.). Embodiments may include: receiving, from a radiofrequency radiation sensor, a main scan of an area, the main scan may include reflections from the area at RF range, and receiving typical roughness values of one or more types of water sources. Embodiments may further include: filtering from the main scan undesired water source types according to their typical roughness values, identifying a desired type of water source in the filtered main scan and receiving from the RF radiation sensor a set of scans of the area, each scan of the area includes reflections in the RF range taken prior to the receiving of the main scan. Embodiments may include calculating the underground water content at locations in the area based on the identified first type of water source and the received set of scans.

A method comprises at least the following steps: a step of acquiring data by radar to obtain an SAR image covering a given geographical domain; a step of acquiring at least one secondary image covering the domain, produced by a source external to the radar, the image supplying information on the colors of the constituent elements of the SAR image; a step of superimposing the SAR image and the secondary image; a step of assigning colors to the elements on the basis of their position in the superimposed secondary image.