Atmospheric and Fog Effects on Ultra-Wide Band Radar Operating at Extremely High Frequencies
The wide band at extremely high frequencies (EHF) above 30 GHz is applicable for high resolution directive radars, resolving the lack of free frequency bands within the lower part of the electromagnetic spectrum. Utilization of ultra-wideband signals in this EHF band is of interest, since it covers...
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| Format: | Article |
| Language: | English |
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MDPI AG
2016-05-01
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| Series: | Sensors |
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| Online Access: | http://www.mdpi.com/1424-8220/16/5/751 |
| _version_ | 1811304018708791296 |
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| author | Nezah Balal Gad A. Pinhasi Yosef Pinhasi |
| author_facet | Nezah Balal Gad A. Pinhasi Yosef Pinhasi |
| author_sort | Nezah Balal |
| collection | DOAJ |
| description | The wide band at extremely high frequencies (EHF) above 30 GHz is applicable for high resolution directive radars, resolving the lack of free frequency bands within the lower part of the electromagnetic spectrum. Utilization of ultra-wideband signals in this EHF band is of interest, since it covers a relatively large spectrum, which is free of users, resulting in better resolution in both the longitudinal and transverse dimensions. Noting that frequencies in the millimeter band are subjected to high atmospheric attenuation and dispersion effects, a study of the degradation in the accuracy and resolution is presented. The fact that solid-state millimeter and sub-millimeter radiation sources are producing low power, the method of continuous-wave wideband frequency modulation becomes the natural technique for remote sensing and detection. Millimeter wave radars are used as complementary sensors for the detection of small radar cross-section objects under bad weather conditions, when small objects cannot be seen by optical cameras and infrared detectors. Theoretical analysis for the propagation of a wide “chirped” Frequency-Modulated Continuous-Wave (FMCW) radar signal in a dielectric medium is presented. It is shown that the frequency-dependent (complex) refractivity of the atmospheric medium causes distortions in the phase of the reflected signal, introducing noticeable errors in the longitudinal distance estimations, and at some frequencies may also degrade the resolution. |
| first_indexed | 2024-04-13T07:58:20Z |
| format | Article |
| id | doaj.art-c4cafa6817d0445497130b6478148007 |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-04-13T07:58:20Z |
| publishDate | 2016-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-c4cafa6817d0445497130b64781480072022-12-22T02:55:21ZengMDPI AGSensors1424-82202016-05-0116575110.3390/s16050751s16050751Atmospheric and Fog Effects on Ultra-Wide Band Radar Operating at Extremely High FrequenciesNezah Balal0Gad A. Pinhasi1Yosef Pinhasi2Faculty of Engineering, Ariel University, Ariel 40700, IsraelFaculty of Engineering, Ariel University, Ariel 40700, IsraelFaculty of Engineering, Ariel University, Ariel 40700, IsraelThe wide band at extremely high frequencies (EHF) above 30 GHz is applicable for high resolution directive radars, resolving the lack of free frequency bands within the lower part of the electromagnetic spectrum. Utilization of ultra-wideband signals in this EHF band is of interest, since it covers a relatively large spectrum, which is free of users, resulting in better resolution in both the longitudinal and transverse dimensions. Noting that frequencies in the millimeter band are subjected to high atmospheric attenuation and dispersion effects, a study of the degradation in the accuracy and resolution is presented. The fact that solid-state millimeter and sub-millimeter radiation sources are producing low power, the method of continuous-wave wideband frequency modulation becomes the natural technique for remote sensing and detection. Millimeter wave radars are used as complementary sensors for the detection of small radar cross-section objects under bad weather conditions, when small objects cannot be seen by optical cameras and infrared detectors. Theoretical analysis for the propagation of a wide “chirped” Frequency-Modulated Continuous-Wave (FMCW) radar signal in a dielectric medium is presented. It is shown that the frequency-dependent (complex) refractivity of the atmospheric medium causes distortions in the phase of the reflected signal, introducing noticeable errors in the longitudinal distance estimations, and at some frequencies may also degrade the resolution.http://www.mdpi.com/1424-8220/16/5/751extremely high frequenciesFMCW radaratmospheremillimeter wavesTera-Hertz frequencies |
| spellingShingle | Nezah Balal Gad A. Pinhasi Yosef Pinhasi Atmospheric and Fog Effects on Ultra-Wide Band Radar Operating at Extremely High Frequencies Sensors extremely high frequencies FMCW radar atmosphere millimeter waves Tera-Hertz frequencies |
| title | Atmospheric and Fog Effects on Ultra-Wide Band Radar Operating at Extremely High Frequencies |
| title_full | Atmospheric and Fog Effects on Ultra-Wide Band Radar Operating at Extremely High Frequencies |
| title_fullStr | Atmospheric and Fog Effects on Ultra-Wide Band Radar Operating at Extremely High Frequencies |
| title_full_unstemmed | Atmospheric and Fog Effects on Ultra-Wide Band Radar Operating at Extremely High Frequencies |
| title_short | Atmospheric and Fog Effects on Ultra-Wide Band Radar Operating at Extremely High Frequencies |
| title_sort | atmospheric and fog effects on ultra wide band radar operating at extremely high frequencies |
| topic | extremely high frequencies FMCW radar atmosphere millimeter waves Tera-Hertz frequencies |
| url | http://www.mdpi.com/1424-8220/16/5/751 |
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