A compact highly sensitive radiometer for thermal sounding of atmosphere in 5 MM band

Хайкин, В. Б.; Radzikhovsky, V.N.; Kuzmin, S.E.; Shlenzin, S.V.; Shaposhnikov, A.V.

doi:10.1109/mrrs.2008.4669547

Cited by 3 publications

(3 citation statements)

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“…In this paper we consider a wide angle smooth-walled spline-profile horn as the MFPA feed for the RATAN-600 radio telescope operating in a multi-beam mode [4]. For an edge taper of −13 dB, a feed spacing of 14 mm (d s =3.2 w 0 ) and reduced (15%→20%) horizontal aperture of the main mirror, we expect a beam spacing of q sÀMin ¼ 2 HPBW without the focal-plane quasi-optics.…”

Section: Multi-beam Mode Of a Radio Telescopementioning

confidence: 99%

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Compact Efficient Feed-Horn at 30–38 GHz for a Multi-beam Radio Telescope

Chernobrovkin

Popenko

Хайкин

et al. 2010

J Infrared Milli Terahz Waves

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The requirements for a feed suitable for a radio telescope multi-beam focal plane array are considered. A smooth-walled spline-profile horn covering the 30-38 GHz frequency band to be used in a multi-beam receiving array of a radio telescope has been optimized, manufactured and tested. The achieved cross-section aperture size of the horn allows us to provide a neighboring beam spacing equal or less than 2HPBW for the RATAN-600 radio telescope. The measured sidelobe levels of the radiation pattern is less than−30dB/−24dB/−26dB in H/E/45 0 -planes, cross-polarization levels better than−20 dB, an input return loss better than −18 dB and the −3dB/−10dB-beamwidths are of the order of 40º/ 80º over the frequency band. Mutual-coupling of adjacent horns is less than−38 dB.

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Section: Multi-beam Mode Of a Radio Telescopementioning

confidence: 99%

“…Another type of array element where the compact packing can occur is the dielectric-rod horn with volume-surface types of waves and axial radiation of the HE 11 mode as a travelling wave. Simulated results of a dielectric-rod horn, its optimization for the multi-beam receiving array, and tests are given in [4].…”

mentioning

confidence: 99%

Compact Efficient Feed-Horn at 30–38 GHz for a Multi-beam Radio Telescope

Chernobrovkin

Popenko

Хайкин

et al. 2010

J Infrared Milli Terahz Waves

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“…For stable aircraft, such as transport planes, the impact of motion error on SAR performance is generally negligible [21][22][23]. However, for drones, atmosphere turbulence can cause a significant motion-induced error compared to manned aircraft [24]. Moreover, due to payload limitations, drone SARs are typically designed with higher frequencies to shorten the wavelength and reduce the size and weight of the RF device, resulting in significant phase error caused by motion error [25].…”

Section: Introductionmentioning

confidence: 99%

Spatially Variant Error Elimination for High-Resolution UAV SAR with Extremely Small Incident Angle

et al. 2023

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Airborne synthetic aperture radar (SAR) is susceptible to atmospheric disturbance and other factors that cause the position offset error of the antenna phase center and motion error. In close-range detection scenarios, the large elevation angle may make it impossible to directly observe areas near the underlying plane, resulting in observation blind spots. In cases where the illumination elevation angle is extremely large, the influence of range variant envelope error and phase modulations becomes more serious, and traditional two-step motion compensation (MOCO) methods may fail to provide accurate imaging. In addition, conventional phase gradient autofocus (PGA) algorithms suffer from reduced performance in scenes with few strong scattering points. To address these practical challenges, we propose an improved phase-weighted estimation PGA algorithm that analyzes the motion error of UAV SAR under a large elevation angle, providing a solution for high-order range variant motion error. Based on this algorithm, we introduce a combined focusing method that applies a threshold value for selection and optimization. Unlike traditional MOCO methods, our proposed method can more accurately compensate for spatially variant motion error in the case of scenes with few strong scattering points, indicating its wider applicability. The effectiveness of our proposed approach is verified by simulation and real data experimental results.

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