New Method of Measuring Phase Characteristics of Antenna Using Doppler Frequency Measurement Technique

2004 ◽  
Vol 52 (12) ◽  
pp. 3312-3318 ◽  
Author(s):  
Q. Liu ◽  
S. Tsuruta ◽  
K. Asari ◽  
J. Ping ◽  
F. Kikuchi ◽  
...  
Keyword(s):  
Measurement Technique ◽  
Doppler Frequency ◽  
Frequency Measurement ◽  
New Method

Enhancement of Radar Imagery by Maximum Entropy Processing

1977 ◽  
Vol 21 (3) ◽  
pp. 241-243 ◽  
Author(s):  
Clanton E. Mancill
Keyword(s):  
Maximum Entropy ◽  
Signal To Noise Ratio ◽  
Super Resolution ◽  
Doppler Frequency ◽  
Frequency Measurement ◽  
Entropy Method ◽  
Frequency Resolution ◽  
Sampled Data ◽  
Maximum Entropy Spectrum ◽  
Using Data

The maximum entropy spectrum (MES), a sampled data power spectrum estimator, is applied to the enhancement of imagery obtained by synthetic array radar (SAR) imaging systems. MES offers better frequency resolution than conventional Fourier transform methods for certain signal classes. Since azimuth ground resolution in SAR systems is obtained by doppler frequency measurement of the radar return, the method is capable of enhancing the resolution of SAR maps. The principal signal requirement is adequate signal-to-noise ratio. The maximum entropy method has been tested using data obtained by the Hughes FLAMR radar system. The super-resolution capabilities of the method are demonstrated using FLAMR images of corner reflector arrays.

A New Airborne Passive DF Method only Based on Frequency Difference

2011 ◽  
Vol 219-220 ◽  
pp. 846-850
Author(s):  
Tao Yu
Keyword(s):  
Direction Cosine ◽  
Doppler Frequency ◽  
Frequency Measurement ◽  
Frequency Difference ◽  
Baseline Length ◽  
Direct Proportion ◽  
Unknown Parameters ◽  
Flight Direction ◽  
Phase Interference ◽  
Circular Functions

If three antenna units are divided into two set and two baselines are placed at right angles to each other in flight plain, in which the direction of one baseline is parallel to the actual flight direction of air vehicle, the sine and cosine function of target bearing respectively in two baseline directions can be simultaneously obtained according to the analysis principle of the direction cosine change rate. The angulations’ formula only based on Doppler frequency difference can be derived after eliminating the unknown parameters including angular velocity and wavelength by the specific value of two circular functions. The analog calculation shows that the relative error is in direct proportion to the baseline length provided that the incident wave is parallel in derivation. But the error analysis depicts that the measurement accuracy is in direct proportion to the baseline length. Moreover, the measurement error relies on mainly the accuracy of frequency measurement. Furthermore, the derived formula has irregularity in airborne axis direction. However, since the new method is not associated with wavelength, this new DF only based on Doppler frequency difference will be more adapted to passive sounding as compared with phase interference method.

Acceleration measurement improvement by application of novel frequency measurement technique for FDS based INS

2014 ◽  
Author(s):  
Fabian N. Murrieta-Rico ◽  
Daniel Hernandez-Balbuena ◽  
Vitalii Petranovskii ◽  
Juan Ivan Nieto Hipolito ◽  
Alexey Pestryakov ◽  
...  
Keyword(s):  
Measurement Technique ◽  
Frequency Measurement ◽  
Acceleration Measurement

scholarly journals Development of a Pressure-Sensitive Coating Using Platinum Octaethylporphyrin

Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1093
Author(s):  
George Catalin Cristea ◽  
Sorina Ilina ◽  
George Pelin ◽  
Adriana Stefan ◽  
Cristina Elisabeta Pelin
Keyword(s):  
High Resolution ◽  
Surface Pressure ◽  
Measurement Technique ◽  
New Method ◽  
Optical Technique ◽  
Pressure Sensitive Paint ◽  
Image Capture ◽  
Pressure Distributions ◽  
Pressure Sensitive ◽  
Sensitive Coating

In recent years, researchers have developed a new method of measuring the pressure on the surface using sensitive paints. This is an optical technique for determining surface pressure distributions by measuring changes in the intensity, emitted by certain excited molecules. The main advantage of the method over traditional techniques is the high resolution of the information. The only limitation of the resolution of a global map generated by the PSP (pressure-sensitive paint) technique is given by the capabilities of the image capture device. This paper describes the development of a technology for obtaining pressure-sensitive paint, in laboratory conditions, as an advanced measurement technique. The method has an application in many fields such as automotive, aerospace, or even medical.

scholarly journals New Method for Cut-off Frequency Measurement of Picoammeter

1982 ◽  
Vol 18 (7) ◽  
pp. 699-703
Author(s):  
Kiyoaki KIKUCHI ◽  
Koji OKAMOTO ◽  
Akira SUZUKI
Keyword(s):  
Frequency Measurement ◽  
New Method

Research on Fm Telemetry Signal Demodulation Based on Instantaneous Frequency Measurement

2014 ◽  
Vol 602-605 ◽  
pp. 2225-2228
Author(s):  
Hui Zhi Zou
Keyword(s):  
Instantaneous Frequency ◽  
Measurement Theory ◽  
Implementation Process ◽  
Doppler Frequency ◽  
Frequency Measurement ◽  
Signal Demodulation ◽  
Frequency Demodulation ◽  
The Impact ◽  
Demodulation Method ◽  
Instantaneous Frequency Measurement

According instantaneous frequency measurement theory, we propose a new PCM/FM telemetry signal demodulation method. This paper introduces the basic principles of this demodulation method and implementation process, the influence of instantaneous frequency measurement accuracy and the impact of factors on the Doppler frequency demodulation performance is proposed to improve the accuracy and instantaneous frequency measurement method demodulation performance. Simulation results show that this method is superior demodulation performance, strong anti-jamming capability, ease of software programming and DSP devices to achieve.

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