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Produced by the NASA Center for Aerospace Information (CASI) https://ntrs.nasa.gov/search.jsp?R=19770008624 2020-03-22T10:44:26+00:00Z
UNIVERSITY OF ILLINOIa
URBANA
z^
Library of Congress ISSN 0368-0581
AERON0MY'REP',C_","1'RT
NO. 74
THE DRBAN4 METEOR-RADAR SYSTEM: DESIGN,
DEVELOPMENT, AND FIRST OBSERVATIONS(ait:jh-1-.,.' 1-+J.301,)AllitivL+lrui liL_vl.l it U. j, ., i /- 1_)567
THE URBANA METEOR - ,RADAR SYSTEM; DESIGN,
DEVELOPMENT, AND FIRST OBSERVATIONS
(Illinois Univ.) 351 p HC A16/8F A01Unclas
CSCL 04A G3/46 59673
by^ti, .r j
G. C. Hessnh^'
11.1. A. GellerC ^,^B19s co,
1•d 9^i
October 1, 1976
. - n
Supported byAeronomy Laboratory
National Aeronautics and Space AdministrationDepartment of Electrical Engineering
Grant NGR 14-005-181 andUniversity of Illinois
National Science Foundation Grant ATM-76-01773Urbana, Illinois ,r f
UILU-ENG 76 2505
A E R O N O M YR E P O R T
N 0.74
THE URBANA METEOR-RADAR SYSTEM: DESIGN,
DEVELOPMENT, AND FIRST OBSERVATIONS
by
G. C. Hess
M. A. Gelleri
i
October 1, 1976
ii
Supported by
National Aeronautics and SpaceAeronomy Laboratory
Administration Grant NGR 14-005-181Department of Electrical Engineering National Science FoundationUniversity of IllinoisGrant ATM 76-01773Urbana, Illinois iii
3ABSTRACT
The design, development, and first observations of a high-power meteor- radar system located near Urbana, Illinois are described. The roughly five- fold increase in usable echo rate compared to other facilities, along with automated digital data processing and interferometry measurement of echo-^ arrival angles, permits unsurpassed observations of tidal structure and shorter period waves. Such observations are discussed at length. Also, the technique of using echo decay rates to infer density and scale height and the technique of inferring wind shear from radial acceleration are examined. Lastly, an original experiment to test a theory of the D-region winter anomaly is presented. i a 'i IV
TABLE OF CONTENTS
ABSTRACT............................
TABLE OFCONTENTS ........................iv
1.INTRODUCTION........................1
1.1Upper Atmosphere Winds ....................1
1.2Experimental Techniques....................2
1.2.1Direct methods....................4
1.2.2Indirect methods..................5
1.3Unique Aspects of the Urbana Meteor-Radar System. . . . ....7
1.4Summary of 1975-1976 Urbana Meteor-Radar Campaign . . . ....9
1.5Objectives and Scope of this Study...... ......11
2.UNIVERSITY OF ILLINOIS METEOR-RADAR SYSTEM ............13
2.1Scientific Criteria and Specifications........13
2.1.1Scientific objectives................13
2.1.2Echo rate and measurement accuracy requirements. ...13
2. 1.3Estimate of system echo rate .........15
2.1.4Estimate of system height accuracy ...........19
2.1.4.1Estimate of systemrange accuracy......20
2.1.4.2Estimate of systemDoppler accuracy.........21
2.1.4.3Estimate of systemazimuth accuracy.........22l
2.1.4.4Estimate of systemelevation accuracy.......26
2.2System Description..... , ..._ ...............26
2.2.1Block diagram........26
2.2.2Hardware subsystems.................29
2.2.2.1Radar director..29
V
2.2.2.1.1Frequency synthesizer...........29
2.2.2.1,2Target generator.............,.32
2.2.2.2Transmitter................37
2.2.2.3Transmitting antenna...............43
2.2.2.4Receiving antennas................56
2.2.2.5Receivers...............56
2.2.2.6Phase detectors..................62
2.2.2.7Computer and interface ..............67
2.2.3Measurement algorithms...............69
2.2.3.1Range determination by curve fitting .... ....69
2.2.3.1.1Overview of the ranging problem.........69
2.2.3.1.2Ratio method ...............77
2.2.3.1.3Parabola method..............f.77
2.2.3.1.4_ Range algorithm accuracy .......80
2.2.3.2Doppler measurement.............82
2.2.3.3Spaced antenna phase comparisons for angles ofarrival.......... _85
2.2.3.4Echo height determination............90
2.2.4System software.................92
2.2.4.1METPb collection and processing software .. . ..92
2.2.4.2Standard post-processing analysis package formeteor radar...........104
3.POST COLLECTION ANALYSIS OF ECHO DATA ................106
3.1Obtaining Wind Values Uniformly Spaced in Time and Height. .106
3.2Effects ofEcho Selection Criteria on Meteor-Radar Wind
Results......_.....................115
3.3Averaging Effect of a Meteor-Radar System without Height
Resolution................130
4..METEOR CHARACTERISTICS..........._ .........136
Vi 4
4.2Meteoric Particles.....................136
4.3Meteor Trails .....................143
4.4Reflection Properties of Individual Trails ... ......149
5.GENERAL COLLECTION STATISTICS..................155
5.1Rcho Strength Distribution................155
5.2Geophysical Noise..................156
5.3Diurnal Parameter Variations .................160
5.4Annual Parameter Variations................174
6.TIDES IN THE UPPER ATMOSPHERE ....................176
6.1Review of Atmospheric Tidal Theory...............176
6.2Tides - Comparisons with Theory and Previous Meteor-Radar
observations ....................182
6.2.1Early observations..........182
6.2.2Seasonal tidal behavior at Adelaide...........183
6.2.3Seasonal tidal behavior at Garchy............184
6.2.4Day-to-daze variations.............192
6.2.5University of Illinois meteor-radar tidal observations194'
6.2.6Discussion of University of Illinois observations. ....194
6.3The TerdiurnaZ Tide...................215
6.4Space-Quadrature Winds ...................218
7.INTERNAL ACOUSTIC-GRAVITY WAVES IN THE UPPER ATMOSPHERE. . ..222
7.1Review of Internal Acoustic-Gravity Wave Theory. . .. . ..222
7.2Partial Reflections of Internal Gravity Waves. .. ..232
7.3Discussion of Short Period Observations............233
7.3.1Garchy studies...........233
7.3.2Ticamarca studies...,.................234
7.3.3Urbana studies.....................235
vii
8.SIMULTANEOUS PARTIAL-REFLECTION AND METEOR-RADAR WIND OBSERVATIONS
AT URBANA,ILLINOIS......................248
8.1Introduction....................248
8.2Differential Absorption Technique............249
8.3Results..........................250
8.4Discussion.......................253
9.INFERENCES ABOUT DENSITY AND SCALE HEIGHT VARIATIONS IN THE UPPER
ATMOSPHERE ............................257
10. SINGLE STATION MEASUREMENTS OF WIND SHEARS IN THE METEOR REGION. . .271
10.1Radial Acceleration Technique.............271
10.2Interpolated Winds Technique .......... .279
11. SUMMARY AND SUGGESTIONS FOR FUTURE RESEARCH...........285
11.1Summary ..........................285
11.2Suggestions for Future Research.......287
REFERENCES.......................289
APPENDIX IFREQUENCY SYNTHESIZER AND TARGET GENERATOR SCHEMATICS..302 APPENDIX IICOMPUTER PROGRAMS....................316 APPENDIX IIIBIAS OF CLIPPED MEAN ESTIMATOR ............333 APPENDIX IVBIAS OF ZERO CROSSING ALGORITHMS WHICH DISCRIMINATE AGAINST
LOW VELOCITIES...................335
I (i
LIST OF TABLES
Tables
viii Page
1.1Meteor-radar facilities..................8
p1.2Summary of University of Illinois meteor-radar operation.10
2.1Frame arrangement for stacked Yagi interferometer ......71
2.2Ratio of the highest sample to the higher of its two neighbors*^
for offset 1Tl front 0-5 us..(a) Receiver bandwidth from 20-
150 kHz; transmitted pulse width is 5 Ps; transmitted pulse
and receiver bandpass are Gaussian [Baekof and BowhiZZ, 1974]. (b) Receiver bandwidth from 20-200 kHz; transmitted pulse width is 10 us and rectangular in shape; receiver bandpass is Gaussian [Edwards,1973a]...........78
2.3Meteor-radar software............94F
3.1CURFIT performance in extracting prevailing wind and tidali
parameters versus echo rate, based on fit to mean + 24 + 12 +8 hrcomponents...................110
3.2Comparison of 2, 3, and 5 harmonic curve fit results,
September 13-14, 1975................114
3.3Low pass nature of the amplitude bias of interpolated winds116
3.4Comparison of three analysis methods on meteor-radar data117
3.5Standard deviation and standard deviation of mean for
methodsin Table3.4.................118
3.6Paired differences for threeanalysis methods of meteor-
radardata.._ ...............120
3.7Meteor echo acceptance criteria for the Perseid run data. . .121
3.8Winds deduced from Fresnel frames only of meteor-radar data .123
3.9Summary of "clipped" data analysis for various thresholds
and rejection percentages................126 T_. ix
3.10Comparison of four analysis methods used to evaluate pre-
vailing wind, diurnal and semidiurnal tides from meteor- radar data,January 17-18,1975...............127
4.1Order of magnitude estimates of the properties of sporadic
meteors[Sugar,1964].................138
4.2Meteor echo collection rate at Urbana, Illinois .....142
5.1University of Illinois meteor radar flux law parameters . . .157
5.2Vertical wind structure at Urbana, January 18, 1975 .....159
5.3Average meteor-radar collection statistics versus time of
day, based on eight decay height runs, January - August, 1975163
5.4Harmonic fits to hourly mean parameter data, eight radar3
runs,January - August,1975................165
5.5(a) Mean correlation coefficient matrix for decay height
runs.(b) Correlation coefficient statistics for decay heightruns ....................166
5.6Hourly interferometer echo height..............169
5.7Average meteor-radar collection statistics versus time of
day, based on eight stacked Yagi runs, September, 1975 -
January,1976...................171
5.8Harmonic fits to hourly mean parameter data, eight stacked
Yagi runs, September, 1975 - January, 1976......172
5.9(a) Correlation coefficientmatrix for stacked Yagi runs.
(b) Correlation coefficient statistics for stacked Yagi runs.173
5.10Summary of average parameter values versus time of year175
6.1Seasonal tidal behavior at Garchy [FeUous et aL., 1975].. .191
6.2Diurnal tide amplitude and phase versus height........195-
6.3Semidiurnal tide amplitude and phase versus height... . .197
fII^-• X
6.4Amplitude shear and vertical wavelength for Sl(v) and S2(v) .199
6.5Mean tidal parameters versus height based on 16 collection
'Iperiods,January,1975 - January,1976............200
6.690 km seasonal tidal statistics for January, 1975 - January,
1976data.........................201
J6.7All height seasonal tidal gradient statistics for January,
6.8Prevailing and tidal winds at Urbana, October 13-17, 1975 ...2141
6.9Terdiurnal tide wavelengths, actual, and nonlinear inter-
actionestimate....................217
6.10Space-quadrature wind components at Urbana...........220
7.1Sample short period wave amplitude and phase height structure236
7.2Least square curve fit parameters for partially reflected
internal gravity waves................237
7.3Wavenumbers and vertical and horizontal wavelengths of short
period waves observed at Urbana................238 7.4I Histograms of short period vertical wavelengths and
7.5Summary of power law fits to averaged wind spectra over
3-24 cycle/day ........ 244
8.1Summary of meteor-radar and partial-reflection observations'
early in1975................252
8.2Summary of all simultaneous meteor-radar and partial-
reflection observations at Urbana ..............254
8.3Correlation coefficient matrix - winter anomaly runs.....255
.9.1Decay height ceilings imposed by software acceptance criteria255
9.2Linear regression analysis of log b and true height h data. .. 262
i
T.... .......................... _,,,..,,,^
j1 1^t 1 xi
9.3Harmonic fits to inferred density ..............266
9.4Scale height harmonic analysis ................268
10.1Behavior of key parameters in the radial acceleration
technique.........................273
10.2Mean differential velocity squared versus displacement....276
10.3Standard deviation of Doppler acceleration magnitude versus
echo duration and signal-to-noise ratio using zero-Doppler
10.4Wind gradient histogram for specially selected echoes ....280
10.5Vertical wind shear magnitude versus time of day.. ...281
10.6Vertical wind shear magnitude versus height ........283
10.7Vertical wind shear magnitude grouped by run and time of day.284
x xii
LIST OF FIGURES
Figurepage
1.1Experimental methods in exploring the atmosphere
VedeZe, 1968] . . . . . . . . . . . . . . . . . . . . . . .3
2.1(a) Peak signal-to-noise ratio versus q, electron lime
density, (b) Peak receiver voltage (50 9 load) versus q, electron line density.. . . . . . . . . r. .. .17
2.2Illustration of the various angles of measurement.. . .23
2.3(a) Range error, (b) Doppler error, (c) Azimuth error versus
number of calculations averaged. .. .. .. . . .25
2.4(a) Four antenna interferometer, (b) Stacked Yagi inter-
ferometer. . . .. . . . .. . .. . ., . . .. .27
2.5Meteor-radar system block diagram.. . . . . . . . .28}
2.6Radar director block diagram. .. . . . . . . . .30
2.7(a) Adjustable secondary target, (b) Dual target and re-
ceiver response.. .. . . .. ..35 -2.8Floor plan of the transmitter. . . . .. . . . . . . . . .38
2.9(a) Dipole geometry, (b) Line of point sources geometry.,
(c) Ground plane geometry, (d) Row of elements geometry. . .45
2.10(a) Total pattern, single row array, (b) Total pattern,
double row array.. . . . . . . . .. . . . . .52
2.11Meteor-radar transmitting antenna feed system. . . . ..55
2 12Block dia ram of receiver ARI model PR-40A58
2.13(a) Receiver passband characteristics [Harrington and
GeZZer, 1975], (b) Receiver transfer functions60
2.14Six receiver diode blanker . .. ... .. ., .61
2.15Five-way splitter for receiver local oscillator... .63
r1r^_ xiii
FigurePage
2.16Balanced demodulator....................65
2.17(a) Quadrature phase comparator waveforms, (b) Video-
balanced demodulator pulse responses ...........66
2.18Four-way splitters for quadrature phase detector reference
signals ...........................68
2.19A/D multiplexer interface ..................70
2.20Meteor-echo region [Backof and BowhiZZ,1974]. .......73
2.21Typical receiver output pulse, with sampling superimposed
[Backof and BowhiZ Z,19741...............,75
2.22Representative wideband receiver range offset error curve
[Harrington and GeUer,1975] ................81
2.23(a) Velocity standard deviation (Backof algorithm),(b)
.Azimuth standard deviation (-y=11°),(c) Elevation standard deviation (a=45°) versus additive noise [Backof and BowhiZZ,
1974] ..........................84
2.24Bowhill velocity ni.gorithm standard deviation versus
(a) Velocity and signal-to-noise ratio,(b) Number of velo a- ities averaged, signal-to-noise ratio, and velocity magni- tude........................86
2.25Histogram of velocities, January 17-18, 1975 ........87
2.26Measurement setup for transmitter output cavity pair phase
difference...............91
3.1Prevailing and tidal winds versus echo rate, mean plus three
harmonicsfit...............112
3,2Prevailing and tidal winds versus echo rate, mean plus five
harmonics fit........113 xiv
FigurePage
3.3Comparison of winds deduced using interferometer and decay
height values, September 13-14,1975............129
4.1(a) Variation in the space density of meteors along the
earth's orbit [Sugar, 1964], (b) Diurnal variation of meteor =t9s ..............*.............140quotesdbs_dbs8.pdfusesText_14
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