An Automatic Detection Scheme for Periodic Signals Based on Spectrum Analyzer Measurements

2004 ◽  
Vol 53 (3) ◽  
pp. 847-853 ◽  
Author(s):  
D. Rabijns ◽  
G. Vandersteen ◽  
W. Van Moer
Keyword(s):  
Automatic Detection ◽  
Spectrum Analyzer ◽  
Detection Scheme ◽  
Periodic Signals

Design on Transmission Accuracy Testing System of Actuator

2014 ◽  
Vol 912-914 ◽  
pp. 633-637
Author(s):  
Ping He ◽  
Chao Liu ◽  
Ying Li ◽  
Zhi Qiang Zhao
Keyword(s):  
Attitude Control ◽  
High Efficiency ◽  
Low Cost ◽  
Automatic Detection ◽  
Measured Parameter ◽  
Testing System ◽  
Detection Scheme ◽  
Executive Mechanism ◽  
Test Requirements ◽  
Hardware Circuit

Actuator is the main executive mechanism for the attitude control of aircraft in the aerospace industry and aviation field. With the further development of technology, higher quality of product research and detection has been required. According to the test requirements, the actuator nonlinear parameter testing system is designed to realise the automatic detection for actuator transmission mechanism on the basis of the research in nonlinear measured parameter of tranmission accuracy. Firstly, the principle and detection scheme of the system was presented. Then the overall structure of the system was designed. After that, the hardware circuit of the system which used TMS320F2812 as main control chip was designed. It mainly consisted of the function of each module and the working process of the system. Finally, the software of the image acquisition system was presented. With the experimental verification, the system realises the automatic detection for tranmission accuracy and has advantages of low cost, high efficiency and strong resistance to interference. The functions and indexes achieved the design requirements..

scholarly journals Automatic Detection of Small Icebergs in Fast Ice Using Satellite Wide-Swath SAR Images

2019 ◽  
Vol 11 (7) ◽  
pp. 806 ◽  
Author(s):  
Ingri Soldal ◽  
Wolfgang Dierking ◽  
Anton Korosov ◽  
Armando Marino
Keyword(s):  
Spatial Resolution ◽  
Barents Sea ◽  
Computation Time ◽  
Automatic Detection ◽  
False Alarms ◽  
Constant False Alarm Rate ◽  
Sar Images ◽  
Detection Scheme ◽  
Fast Ice ◽  
Wide Swath

Automatic detection of icebergs in satellite images is regarded a useful tool to provide information necessary for safety in Arctic shipping or operations over large ocean areas in near-real time. In this work, we investigated the feasibility of automatic iceberg detection in Sentinel-1 Extra Wide Swath (EWS) SAR images which follow the preferred image mode in operational ice charting. As test region, we selected the Barents Sea where the size of many icebergs is on the order of the spatial resolution of the EWS-mode. We tested a new approach for a detection scheme. It is based on a combination of a filter for enhancing the contrast between icebergs and background, subsequent blob detection, and final application of a Constant False Alarm Rate (CFAR) algorithm. The filter relies mainly on the HV-polarized intensity which often reveals a larger difference between icebergs and sea ice or open water. The blob detector identifies locations of potential icebergs and thus shortens computation time. The final detection is performed on the identified blobs using the CFAR algorithm. About 2000 icebergs captured in fast ice were visually identified in Sentinel-2 Multi Spectral Imager (MSI) data and exploited for an assessment of the detection scheme performance using confusion matrices. For our performance tests, we used four Sentinel-1 EWS images. For judging the effect of spatial resolution, we carried out an additional test with one Sentinel-1 Interferometric Wide Swath (IWS) mode image. Our results show that only 8–22 percent of the icebergs could be detected in the EWS images, and over 90 percent of all detections were false alarms. In IWS mode, the number of correctly identified icebergs increased to 38 percent. However, we obtained a larger number of false alarms in the IWS image than in the corresponding EWS image. We identified two problems for iceberg detection: 1) with the given frequency–polarization combination, not all icebergs are strong scatterers at HV-polarization, and (2) icebergs and deformation structures present on fast ice can often not be distinguished since both may reveal equally strong responses at HV-polarization.

Complex spectrum analyzer of low-frequency periodic signals

1983 ◽  
Vol 26 (8) ◽  
pp. 674-677
Author(s):  
Yu. K. Rybin ◽  
V. P. Budeikin
Keyword(s):  
Low Frequency ◽  
Spectrum Analyzer ◽  
Complex Spectrum ◽  
Periodic Signals
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