The effect of signal saturation on wind velocity estimates using MF radar signals

Yamazaki, Ryozo; Igarashi, K.; Nagayama, M.; Nishimuta, I.

doi:10.1016/s0273-1177(99)00922-9

Cited by 7 publications

(6 citation statements)

References 2 publications

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“…which contains a division by the determinant of the coefficient matrix, AB − H2 ≡ ∆. Yamazaki et al (2000) found that the extremely high values occurred when AB ≈ H2, meaning ∆ ≈ 0. AB ≈ H2 implies that equation 2 describes an ellipse with a high axial ratio, i.e.…”

Section: Relationship With Pattern Axial Ratiomentioning

confidence: 95%

“…The relationship between high axial ratio and extremely high wind measurements was discussed by Yamazaki et al (2000).…”

Section: Relationship With Pattern Axial Ratiomentioning

confidence: 99%

“…They performed a study of the FCA technique which involved storing and manipulating raw radar signals to observe the behaviour on the outcomes of the FCA calculation. Yamazaki et al (2000) found that by artificially clipping raw radar signals before applying FCA, the resulting wind speeds sometimes reach extremely high values at low levels of saturation. They point out that the source is the final step in the FCA calculation, which involves solving the following system of linear equations:…”

Section: Relationship With Pattern Axial Ratiomentioning

confidence: 99%

“…listed by Briggs (1984) (albeit with a misstatement of the direction of the inequality). Interestingly, Yamazaki et al (2000) present scenarios with both AB > H2 and AB < H2 for their unsaturated results, suggesting that this rejection criteria was not included in their analysis.…”

Section: Relationship With Pattern Axial Ratiomentioning

confidence: 99%

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Mesospheric winds measured by MF radar with Full Correlation Analysis: error properties and impacts on studies of wind variance

Gibbins¹,

Kavanagh²

2019

Preprint

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Abstract. The mesosphere is one of the most difficult parts of the atmosphere to sample; too high for balloon measurements and too low for in-situ satellites. Consequently there is a reliance on remote sensing (either from the ground or from space) to diagnose this region. Ground based radars have been used since the second half of the 20th century to probe the dynamics of the mesosphere; Medium Frequency (MF) radars provide estimates of the horizontal wind fields and are still used to analyse tidal structures and planetary waves that modulate the meridional and zonal winds. The variance of the winds has traditionally been linked qualitatively to the occurrence of gravity waves. In this paper the method of wind retrieval (full correlation analysis) employed by MF radars is considered with reference to two systems in Antarctica at different latitude (Halley at 76° S and Rothera at 67° S). It is shown that the width of the velocity distribution and occurrence of ‘outliers’ is related to the measured levels of anisotropy in the received signal pattern. The magnitude of the error distribution, as represented by the wind variance, varies with both insolation levels and geomagnetic activity. Thus it is demonstrated that for these two radars the influence of gravity waves may not be the primary mechanism that controls the overall variance.

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Section: Relationship With Pattern Axial Ratiomentioning

confidence: 95%

“…The relationship between high axial ratio and extremely high wind measurements was discussed by Yamazaki et al (2000).…”

Section: Relationship With Pattern Axial Ratiomentioning

confidence: 99%

Section: Relationship With Pattern Axial Ratiomentioning

confidence: 99%

Section: Relationship With Pattern Axial Ratiomentioning

confidence: 99%

See 2 more Smart Citations

Mesospheric winds measured by MF radar with Full Correlation Analysis: error properties and impacts on studies of wind variance

Gibbins¹,

Kavanagh²

2019

Preprint

View full text Add to dashboard Cite

show abstract

“…Location of the two MF radars used in this study (Halley and Rothera) marked as red squares, with the locations of the geocentric (black) and geomagnetic (purple) south poles. The dashed black lines give estimates of the extent of the polar vortex from May (inner) to August (outer) (from Zhang et al, 2017). The greenshaded region shows the statistical location of the auroral oval for quiet geomagnetic activity (Holzworth and Meng, 1975).…”

Section: Introductionmentioning

confidence: 99%

Mesospheric winds measured by medium-frequency radar with full correlation analysis: error properties and impacts on studies of wind variance

Gibbins

Kavanagh

2020

Geosci. Instrum. Method. Data Syst.

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Abstract. The mesosphere is one of the most difficult parts of the atmosphere to sample; it is too high for balloon measurements and too low for in situ satellites. Consequently, there is a reliance on remote sensing (either from the ground or from space) to diagnose this region. Ground-based radars have been used since the second half of the 20th century to probe the dynamics of the mesosphere; medium-frequency (MF) radars provide estimates of the horizontal wind fields and are still used to analyse tidal structures and planetary waves that modulate the meridional and zonal winds. The variance of the winds has traditionally been linked qualitatively to the occurrence of gravity waves. In this paper, the method of wind retrieval (full correlation analysis) employed by MF radars is considered with reference to two systems in Antarctica at different latitude (Halley at 76∘ S and Rothera at 67∘ S). It is shown that the width of the velocity distribution and occurrence of “outliers” is related to the measured levels of anisotropy in the received signal pattern. The magnitude of the error distribution, as represented by the wind variance, varies with both insolation levels and geomagnetic activity. Thus, it is demonstrated that for these two radars the influence of gravity waves may not be the primary mechanism that controls the overall variance.

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15.3: Development of Side‐Roll and Top‐Roll Panels for an RGBW High‐Resolution Flexible Display Using a White OLED with Microcavity Structure

Kataish

Sasaki

Toyotaka

et al. 2014

Symp Digest of Tech Papers

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The effect of signal saturation on wind velocity estimates using MF radar signals

Cited by 7 publications

References 2 publications

Mesospheric winds measured by MF radar with Full Correlation Analysis: error properties and impacts on studies of wind variance

Mesospheric winds measured by MF radar with Full Correlation Analysis: error properties and impacts on studies of wind variance

Mesospheric winds measured by medium-frequency radar with full correlation analysis: error properties and impacts on studies of wind variance

15.3: Development of Side‐Roll and Top‐Roll Panels for an RGBW High‐Resolution Flexible Display Using a White OLED with Microcavity Structure

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