The NASA/GSFC 94 GHz Airborne Solid State Cloud Radar System (CRS)

AbstractThe NASA/Goddard Space Flight Center’s (GSFC’s) W-band (94 GHz) Cloud Radar System (CRS) has been comprehensively updated to modern solid-state and digital technology. This W-band (94 GHz) radar flies in nadir-pointing mode on the NASA ER-2 high-altitude aircraft, providing polarimetric reflectivity and Doppler measurements of clouds and precipitation. This paper describes the design and signal processing of the upgraded CRS. It includes details on the hardware upgrades (SSPA transmitter, antenna, and digital receiver) including a new reflectarray antenna and solid-state transmitter. It also includes algorithms, including internal loop-back calibration, external calibration using a direct relationship between volume reflectivity and the range-integrated backscatter of the ocean, and a modified staggered-PRF Doppler algorithm that is highly resistant to unfolding errors. Data samples obtained by upgraded CRS through recent NASA airborne science missions are provided.

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Design and Implementation of Multi-Frequency Digital Receiver Based on FPGA

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.643.117 ◽

2014 ◽

Vol 643 ◽

pp. 117-123

Author(s):

Yu Peng Liu ◽

Chao Du ◽

Dong Lin Liu

Keyword(s):

Digital Technology ◽

Wide Band ◽

Radar System ◽

Center Frequency ◽

Beam Forming ◽

Digital Receiver ◽

Effective Implementation ◽

Great Performance ◽

Implementation Method ◽

Band Signal

Recently, the concept of software radar has been proposed. The wide application of the digital technology has become a trend. With the development of modern radar system, the system requires higher and higher performance to the radar receiver. The technology of digital receiver has become an effective implementation method for high-accuracy and wide-band radar receiving systems. However, most of the digital receiver can only receive one wide-band signal with one center frequency. A multi-frequency digital receiver which can receive several center frequencies of signal simultaneously [1] is discussed in this paper. We also describe the theory and the design about digital receiver, introduce digital downconversion (DDC), FIR and decimation, digital beam forming and channel calibration. Based on the research, a realization of multi-frequency digital receiver based on FPGA is put forward. The analysis and simulation is made and the result shows the design of great performance.

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POSIBILITY OF CREATING A PRINTED SINGLE-LAYER TRANSREFLECTOR WITH INCREASED PHASE EFFICIENCY

Issues of radio electronics ◽

10.21778/2218-5453-2019-5-139-145 ◽

2019 ◽

pp. 139-145

Author(s):

A. N. Mikhailov

Keyword(s):

Printed Circuit Board ◽

Single Layer ◽

Circuit Board ◽

Horizontal Polarization ◽

Radiation Characteristics ◽

Printed Circuit ◽

W Band ◽

New Type ◽

Reflectarray Antenna ◽

Geometrical Dimensions

A new type of single‑layer transrefleсtor structure based on microstrip reflective antenna array is described. The developed device is a single‑layer printed circuit board on one side of which a system of printed reflectors is located, and on the other is a polarization structure consisting of parallel metal conductors, in contrast to a microstrip reflectarray antenna. The shape and geometrical dimensions of printed reflectors arranged in a rectangular or hexagonal (triangular) pattern are chosen in such a way that they transform a spherical front of an incident vertically polarized electromagnetic wave into a flat front of reflected wave. In the case of irradiation of the developed transreflector with a horizontal polarization wave, the printed structure makes minimal electromagnetic energy loss during its passage. The results of characteristics modeling (including phase curves) of an element of the reflective lattice in the W‑band for different angles of incidence of the wave on the planar structure under study are given. Based on the results obtained, the sizes of the reflective elements of the transreflector, which provide for the correction of the incident wave with the necessary phase discrete, are determined and an electrodynamic model of the transreflector antenna is built. The simulation of the main radiation characteristics of the antenna with the developed single‑layer transreflector was carried out.

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Feasibility evaluations of three-dimensional-printed high-gain reflectarray antenna for W-band applications

IEICE Communications Express ◽

10.1587/comex.2018xbl0038 ◽

2018 ◽

Vol 7 (6) ◽

pp. 230-235 ◽

Cited By ~ 1

Author(s):

Shunichi Futatsumori ◽

Kazuyuki Morioka ◽

Akiko Kohmura ◽

Nobuhiro Sakamoto ◽

Tomio Soga ◽

...

Keyword(s):

Three Dimensional ◽

High Gain ◽

W Band ◽

Reflectarray Antenna

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Concept for a low cost, high efficiency precipitation radar system based on ferroelectric reflectarray antenna

2009 IEEE Radar Conference ◽

10.1109/radar.2009.4977135 ◽

2009 ◽

Author(s):

Robert Romanofsky ◽

Carl Mueller ◽

Chandra V. Chandrasekar

Keyword(s):

High Efficiency ◽

Low Cost ◽

Radar System ◽

Precipitation Radar ◽

Reflectarray Antenna

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W-Band FMCW MIMO Radar System for High-Resolution Multimode Imaging With Time- and Frequency-Division Multiplexing

IEEE Transactions on Geoscience and Remote Sensing ◽

10.1109/tgrs.2020.2971998 ◽

2020 ◽

Vol 58 (7) ◽

pp. 5042-5057 ◽

Cited By ~ 2

Author(s):

Se-Yeon Jeon ◽

Sumin Kim ◽

Jeongbae Kim ◽

Seok Kim ◽

Seungha Shin ◽

...

Keyword(s):

High Resolution ◽

Mimo Radar ◽

Radar System ◽

Frequency Division Multiplexing ◽

Frequency Division ◽

W Band

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Ice Cloud Retrievals and Analysis with the Compact Scanning Submillimeter Imaging Radiometer and the Cloud Radar System during CRYSTAL FACE

Journal of Applied Meteorology ◽

10.1175/jam2250.1 ◽

2005 ◽

Vol 44 (6) ◽

pp. 839-859 ◽

Cited By ~ 71

Author(s):

K. Franklin Evans ◽

James R. Wang ◽

Paul E. Racette ◽

Gerald Heymsfield ◽

Lihua Li

Keyword(s):

Particle Diameter ◽

Submillimeter Wave ◽

Radar System ◽

Regional Study ◽

Bayesian Algorithm ◽

Ice Clouds ◽

Ice Cloud ◽

Cloud Radar ◽

Brightness Temperatures ◽

Ice Water

Abstract Submillimeter-wave radiometry is a new technique for determining ice water path (IWP) and particle size in upper-tropospheric ice clouds. The first brightness temperatures images of ice clouds above 340 GHz were measured by the Compact Scanning Submillimeter Imaging Radiometer (CoSSIR) during the Cirrus Regional Study of Tropical Anvils and Cirrus Layers (CRYSTAL) Florida Area Cirrus Experiment (FACE) campaign in July 2002. CoSSIR operated with 12 channels from receivers at 183, 220, 380, 487, and 640 GHz. CoSSIR and the nadir-viewing 94-GHz Cloud Radar System (CRS) flew on the NASA ER-2 airplane based out of Key West, Florida. A qualitative comparison of the CoSSIR brightness temperatures demonstrates that the submillimeter-wave frequencies are more sensitive to anvil ice cloud particles than are the lower frequencies. A Bayesian algorithm, with a priori microphysical information from in situ cloud probes, is used to retrieve the IWP and median mass equivalent sphere particle diameter (Dme). Microwave scattering properties of random aggregates of plates and aggregates of frozen droplets are computed with the discrete dipole approximation (DDA) and an effective medium approximation tuned to DDA results. As a test of the retrievals, the vertically integrated 94-GHz radar backscattering is also retrieved from the CoSSIR data and compared with that measured by the CRS. The integrated backscattering typically agrees within 1–2 dB for IWP from 1000 to 10 000 g m−2, and while the disagreement increases for smaller IWP, it is typically within the Bayesian error bars. Retrievals made with only the three 183- and one 220-GHz channel are generally as good or better than those including 380 ± 6.2 and 640 GHz, because the CoSSIR submillimeter-wave channels were much noisier than expected. An algorithm to retrieve profiles of ice water content and Dme from CRS and CoSSIR data was developed. This Bayesian algorithm also retrieves the coefficients of an IWC–radar reflectivity power-law relation and could be used to evaluate radar-only ice cloud retrieval algorithms.

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