2.1 Subsurface Radar Investigation of Arched Wall Aperture
By: S. I. Ivashov, V.V. Razevig, A.P. Sheyko, and I.A. Vasilyev
Remote Sensing Laboratory, Ltd., Russia
and: D.J. Desmond
Sustainable Systems Research | Abstract: Subsurface holographic radar using a monochromatic signal has been developed. It is intended for surveying building structures and works. The characteristic feature of this device is the possibility of obtaining in a sounding plan the microwave images featuring a high resolution attaining 2...3 cm. The main application of this device includes the survey of building constructions to reveal their internal structure and defects. An arched aperture in brick wall was studied with help of the radar to search metallic beams. The goal of investigation was evaluation of load-carrying ability of the wall. |
2.2 Digital Local-Oscillator Generation Using a Delta-Sigma Technique
By: J. W. de Graaf and B.H. Cantrell
Naval Research Laboratory | Abstract: Local-oscillator (LO) signals in up/down converters for most radar systems are typically generated using synthesizers, bench sources, custom-built frequency sources or direct-digital synthesis (DDS). In a digital-array radar (DAR) concept, a single-bit delta-sigma technique was considered as a viable alternative to encode sine waves digitally for LO signal generation. This technique is applied to synthesize sinusoidal signals at a low frequency. These signals are then injected into a frequency multiplier system for generating LO signals. When independently coded delta-sigma sine waves are created offline on a per element basis for a phased array system, the in-band noise shaped response improves as a result of digital beam forming (DBF). In this paper, a single-bit encoding technique for LO signal generation is discussed. Some simulation results are provided as well as a candidate microwave design for a frequency multiplier system. |
2.3 Direction/ Time of Arrival (D/TOA) Estimation Characteristics of the MUSIC Algorithm for the Actual Extended Targets of the Chirp Pulse Tracking Radar
By: Michio Uneda
Kanazawa Institute of Technology
and: Hirokazu Hokazono
Japan Defense Agency | Abstract: This paper proposed the time space MUSIC technique using the chirp pulse signal of the tracking radar. Direction/Time of Arrivals (D/TOA) estimation characteristics were evaluated for the simulated point sources simulated extended air targets, and the actual extended air targets. It is shown that the proposed technique is enable to highly resolve and precisely estimate D/TOA of the actual targets covered by one radar beam width. |
2.4 Time and Frequency Synchronization in Multistatic Radar
By: Terje Johnsen
Norwegian Defence Research Establishment | Abstract: The use of time and frequency references disciplined to GPS has been studied in the context of use in multi-static radar. Several reference units with civilian GPS receivers were tested. Differences in 1PPS fluctuations were observed that would result in ranging errors when stable GPS signals were received. If GPS signals were lost further control of reference output depends on the stability of the reference unit. Drift in frequency and corresponding time deviation was observed according to reference quality. The stable rubidium references was found to give reliable synchronization output for long time without synchronization. |
2.5 AIRIES: A High-Resolution Shipboard Radar
By: Felix Perez, Alberto Asensio, Javier Gismero, and Jose I. Alonso
Universidad Politecnica de Madrid
and: Jose M. Monje, Fernando Casanova, and Rafael Cortijo
Indra Sistemas S.A., Spain
and: Jose F. Perez-Ojeda
Spanish Ministry of Defense | Abstract: This paper introduces the new ARIES radar, a high-resolution surveillance system designed for operation at sea. Its main characteristics are described, together with some remarkable experimental results regarding high-resolution observation of sea clutter and real targets. |
2.6 FOPEN SAR Imaging of Ground Moving Targets Using Rotational Time-Frequency-Radon Transforms
By: Victor C. Chen, Ronald Lipps, and Maitland Bottoms
Naval Research Laboratory | Abstract: In this paper, we introduce the basic concept of the rotational Fourier transform, the bilinear rotational time-frequency transforms, and the Radon transform. Based on a certain model of radar returns from moving targets, we propose a method using a rotational time-frequency-Radon transform for synthetic aperture radar imaging of moving targets in foliage. |
2.7 Frequency Coded Waveforms for Enhanced Delay-Doppler Resolution
By: Chieh-Fu Chang and Mark R. Bell
Purdue University | Abstract: In this research, we propose techniques for the construction of frequency coding sequences that give rise to frequency coded waveforms having ambiguity functions with a clear area containing no side-lobes in a connected region surrounding the main lobe. In this sense, the proposed sequences have excellent delay-Doppler resolution properties and achieve locally optimal ambiguity functions in the region surrounding the main lobe. These sequences are called pushing sequences. First, two important properties of pushing sequences are investigated: the group D4 dihedral symmetry property and the frequency omission property. We also note that Costas sequences have these two properties and the implications of this are investigated. Next, we show how to construct pushing sequences having ambiguity functions with arbitrary-size clear areas. Finally, we analyze the sidelobe distribution and provide the general form of all sidelobe peak positions, and both the lower and upper bound of each sidelobe peak level. |
2.8 Radar Breadboard for DSP Scatterometer
By: Dorothy K. Stosic and James P. Lux
Jet Propulsion Laboratory | Abstract: The design and test results for the Radio Frequency (RF) portion of a breadboard polarimetric scatterometer operating at 13.402 GHz are presented. To evaluate the feasibility of a programmable Digital Signal Processing (DSP) approach for a follow-on scatterometer similar to SeaWinds (scheduled for launch in winter 2002) an integrated breadboard has been developed at the Jet Propulsion Laboratory (JPL). Early breadboards of this type have been identified as valuable assets in developing effective subsystem requirements for the eventual flight instrument. Many compatibility and partitioning issues between the RF and DSP hardware are addressed with empirical results derived from the aforementioned breadboard. The RF portion of the breadboard consists of a dual channel receiver, heterodyning the received signal of 13.402 GHz down to an IF of 37 MHz and a single channel transmitter, that converts the I/Q baseband transmit waveform up to Ku band. The breadboard makes provision for emulating capabilities such as programmable attenuators, loop-back calibration, and saturation effects in an actual instrument's power amplifier. It also provides control interfaces to allow early verification of software control algorithms. |
2.9 Northrop Grumman Radar Simulation (AVSIM)
By: Richard H. Worsham
Northrop Grumman Corp. | Abstract: The Northrop Grumman Avionics Simulation (AVSIM) is one of a set of simulations focused on fighter class radar. It is designed to support a variety of analysis and development activities, spanning requirements analysis, radar software development, performance evaluation, and pilot interfaces. This paper describes AVSIM and the simulation architecture that surrounds it. The model provides high fidelity representations of Air-to-Air and Air-to-Ground radar modes, encompassing detection capability, measurement errors, tracking performance, and timelines. Analytical models are used to represent high data rate signal processing functions, while operational software is used for less intensive data processing such as radar control and tracking activities. AVSIM can be driven by models such as the Joint Integrated Mission Model (JIMM), or by tightly controlled scenarios from its own Scenario Generator. It can be run in real time as part of a cockpit simulator, or in Monte Carlo mode for detailed performance analysis. Extensive post processing capabilities provide insight into radar detection, measurement errors, tracking, and time-line performance. Scan patterns are also visualized, via playback capabilities. AVSIM represents a substantial advance in the state of the art for high fidelity multi-use avionics simulations. |