C
clutter measurement sites near,
37
Canadian Rocky Mountains,
37
CDC (Clutter Data Collection),
257
cell-level aggregation,
99
CFAR (constant-false-alarm rate),
292,
314
circular polarization,
598
amplitude distributions,
22
azimuthal smearing of,
287
in shadowed terrain regions,
398
lack of range dependency in,
305
percent circumference in,
300,
351
percent of circumference vs range in,
299,
312
percentage of cells in,
351
spectral power density,
616,
617
spillover into shadowed regions,
402–403
within wide annular regions,
379–387
clutter amplitude distributions
angle of illumination and,
43
at negative depression angles,
95
dependence of spread on depression angle,
289
depression angle and,
68–71
depression angle vs shadowing,
59
high-relief agricultural terrain,
495
level agricultural terrain,
505–506
low-relief agricultural terrain,
499
repeat sector patches,
209
rural/low-relief patches,
100
standard deviation-to-mean ratio,
222–227
upper and lower bounds,
275
from visible regions of terrain,
297
overall ensemble distribution of,
74–75
parametric dependencies in,
24
probability distributions,
544
spatial cell-to-cell variability of,
544
spatial correlation of,
290
statistical measures of,
24
MTI improvement factor of,
617
radiation between radar and,
24
spectral power ratio in,
581
vertical scatterers in,
25
as area-density function,
Clutter Data Collection (CDC),
257
site-specific prediction of,
287
clutter measurements, ,
13–16
effect of radar resolution on,
110–111
DTED (digitized terrain elevation data) in,
65–67
ensemble aggregations of cell-level statistics in,
98
non-patchy approaches to,
290
site-specific approach to,
23,
343
two-distribution approach,
334
cell-to-cell variability within,
16
classification by terrain slope,
65
Gull Lake West, Manitoba,
47–50
in terms of landform,
409
interclutter visibility and,
microshadowing within,
275,
317
terrain descriptive information,
127
Wolseley, Saskatchewan,
442
output from single delay-line canceller,
617
predicting in Doppler cells,
604
clutter prediction,
16–22
empirical approach to,
17
simplified approach to,
440
from area-extensive terrain surfaces,
46
current vs historical measurements,
659–661
effects of instrumentation on,
672–674
fast-diffuse exponential component,
665
L-band measurements of,
667
matching with analytic shapes,
662
wideband background component,
666
kurtosis, coefficient of,
130
sampling populations,
425
skewness, coefficient of,
130
cell-to-cell variability in,
261
classification by land cover,
65
classification by landform,
65
cumulative distributions of,
127
depression angle and,
20,
415
diurnal variability and,
235
effects of antenna height on,
201
effects of illumination angle on,
66
effects of microshadowing on,
317
effects of polarization on,
414
effects of weather and season on,
231–234
percentile levels of,
389
polarization dependence on,
212–215
seasonal differences in,
235
clutter strength number,
408
clutter to noise power ratio
See (CNR)
CNR (clutter to noise power ratio),
621
coefficient of determination,
135
coherent processing interval
See (CPI)
clutter patch histograms,
126
low-angle clutter measurements,
312–314
multifrequency clutter measurements,
177
terrain elevation data at,
313
constant-false-alarm rate
See (CFAR)
Convair 580 aircraft,
106
antenna height variations at,
197–201
repeat sector measurements,
163–164
correlation distance,
335
vs radar carrier frequency,
338
CPI (coherent processing interval),
581
cumulative distribution function,
127,
548
D
Defence Evaluation and Research Agency,
307
Defence Research Establishment Ottawa
See (DREO)
degrees of freedom
See (DOF)
effects on clutter histogram shapes,
56
effects on spread in clutter amplitude statistics,
415
equation for computing,
56
terrain elevation and,
415
clutter strength vs depression angle,
297
LCE clutter spectrum for,
585
strength vs radar frequency,
545
detection, probability of,
622
digital-to-analog (D/A) converter,
253
digitized terrain elevation data
See (DTED)
Dirac delta function,
577
direction-of-arrival
See (DOA)
in visible terrain regions,
398
DOA (direction-of-arrival),
625
DOF (degrees of freedom),
628
dominant-to-Rayleigh reflector ratio,
335
clutter cross section in,
605
exponential clutter distribution in,
617–618
Gaussian clutter distribution in,
618–619
transformation from Doppler velocity,
616
of windblown clutter spectra,
579
transformation to Dopper frequency,
616
DREO (Defence Research Establishment Ottawa),
397,
655
DTED (digitized terrain elevation data), ,
62–64
clutter strength vs grazing angle,
62–63
for hypotheitical hilltop sites,
360
geometric terrain visibility in,
307
in clutter prediction,
45,
542
in defining depression angle,
19
photogrammetric source,
312
prediction of shadowed regions,
398
G
Gaussian shape parameter,
622,
640
general mixed rural terrain
land clutter coefficients for,
429–436
clutter strength and,
353
GIS (geographic information system),
316
goodness-of-fit hypothesis test,
570
grain storage elevators,
74
clutter strength vs depression angle,
297
antenna mast height and,
58
dependence of background clutter on,
400
in clutter data analysis,
415
Great Salt Lake Desert,
202
effects of polarization,
414
effects of terrain shadowing,
371–379
high-range resolution,
46
low-range resolution,
44–46
source of intrinsic fluctuation,
575
variability in mean strength of,
243
ground clutter measurements,
13–16
dominant clutter sources,
43
Gull Lake East, Manitoba,
52
Gull Lake West, Manitoba,
47–50
multifrequency ground clutter maps,
154
repeat sector measurements,
155
seasonal effects on clutter measurements in,
112
H
harmonic oscillators,
642
Hewlett Packard signal generator,
250
strength vs radar range,
58–60
high-range resolution,
46
high-relief agricultural terrain
clutter amplitude distributions,
495
mean clutter strength for,
493
clutter amplitude distributions,
532
clutter amplitude distributions,
511
VHF polarization bias in,
511 See also forest
high-relief landform,
158
high-speed data recorders,
250
computation of clutter statistics,
129
of classified groups,
420
vs vertical polarization,
432
L
Laboratoire Central de Telecommunications,
658
backscattering coefficient,
42
long-range diffraction-illuminated,
25
low-range resolution,
44–46
strength vs radar frequency,
168
land clutter coefficients
high-relief agricultural terrain,
493–496
high-relief general mixed rural terrain,
429–434
level agricultural terrain,
501–506
low-relief agricultural terrain,
496–501
low-relief general mixed rural terrain,
434–436
land clutter measurements
as backscatter sources,
318
discrete vertical features in,
62
mean clutter strength in classes of,
308–309
mean clutter strength in classes of,
308–309
vertical features on,
43,
62
desert clutter spectra,
611
mean clutter strength vs polarization at,
213
STAP system performance at,
631–635
L-band Clutter Experiment.
See LCE
primary design objective of,
584
leaf velocity distribution,
650
mountain clutter measurements at,
268–272
repeat sector measurements,
172
level agricultural terrain
clutter amplitude distributions,
505–506
clutter amplitude distributions,
535,
536
mean clutter strength,
536
frequency dependencies of clutter in,
163–165
Lincoln Laboratory, ,
242
clutter measurement program, ,
13–16
lognormal distributions,
416
within wide annular regions,
379–387
long-range mountain clutter
low range resolution,
44–46
low reflectivity areas,
115
low-angle clutter, ,
56–58
cell-to-cell variability in,
110
clutter strength vs range,
58
depression angle characteristics of,
104
dominant sources of,
43,
344
effects of trees on,
91–93
high-relief terrain in,
82
low-relief terrain in,
82
multifrequency results of,
243
spatial amplitude distributions,
115
spatial resolution in,
18
low-observable technology,
low-relief agricultural terrain
clutter amplitude distributions,
499
mean clutter strength,
496
patch-to-patch variability in,
500
clutter amplitude distributions,
535
clutter amplitude distributions,
517
intermediate depression angle and,
180–182
low depression angle,
183
terrain elevation data,
513
uncertain outliers in,
516
low-relief terrain,
66,
75,
82
M
predicting the existence of,
289
azimuth averaging through,
387
spatial dilution of clutter with,
307
clutter patch measurements,
555–558
clutter patch selection at,
409–410
mountain clutter measurements at,
268–272
clutter strength vs depression angle,
297
effect on terrain visibility,
360–364
agricultural terrain,
106
high-relief agricultural terrain,
493
low-relief agricultural terrain,
496
one-sigma variability of,
417
vs median clutter strength,
102
mean-to-median ratio,
427
in clutter histograms,
422
median clutter strength,
427
vs mean clutter strength,
102
vs percent tree cover,
92
method of moments,
25,
259
effects of depression angle on,
413–414
effects on clutter strength,
317
in clutter measurements,
51–52
in low-relief forest,
514
vs angle of illumination,
43
vs depression angle in clutter patches,
102
minimum least squares
See (MLS)
MIT Radiation Laboratory,
594
MLS (minimum least squares),
636
of clutter amplitude distributions,
376
bi-modal distributions of,
80–82
multifrequency measurements of,
172–174
clutter amplitude distributions,
539
clutter strength vs radar frequency in,
172–174
moving target indicator
See (MTI)
MTI (moving target indicator),
23
impact of windblown clutter spectra on,
621–623
signal-to-interference power ratio,
621–623
multifrequency clutter measurements
Gull Lake West, Manitoba,
155
multipath reflections,
44
interference on direct illumination,
161
P
parabolic equation,
25,
259
patch amplitude distributions,
308
classification by terrain slope,
65
statistical convergence,
100
pattern propagation factor F,
16,
161
clutter strength and,
163,
413
Peace River, Alberta,
287
clutter patch measurements,
555–558
percent circumference,
351
of long-range clutter strength,
389
Phase One clutter measurements
360-degree survey data,
146
clutter strength vs antenna height,
201
repeat sector patches,
160
seasonal revisits of,
235
clutter strength vs antenna height,
201
microshadowing vs depression angle,
102
standard deviation-to-mean vs depression angle,
101
summer vs winter data,
112
elevation pattern gain variation,
123–125
schematic diagram of,
118
plan position indicator.
See PPI
clutter patches at,
77–80
repeat sector measurements,
172–174
dependence of clutter strength on,
212–215
effects on ground clutter strength,
414
invariance with clutter spectra shape,
597–598
Weibull mean strength and,
418
spectral shape function,
582
power spectral density
See (PSD)
PPI (plan position indicator), ,
36
Peace River, Alberta,
287
precision IF attenuator,
14,
36
in Phase Zero receiver,
118
PRF (pulse repetition frequency),
327,
583
PRI (pulse repetition interval),
336
input clutter power within,
616
probability density function,
136
probability of detection,
622
probability of false alarm,
622
PSD (power spectral density),
576
pulse repetition frequency.
See PRF
pulse repetition interval.
See PRI
land clutter coefficients for,
440
R
AEW (airborne early-warning),
620
detection performance of,
417,
621
finite sensitivity limits,
371
PRI (pulse repetition interval),
119
Raytheon Mariners Pathfinder 1650/9XR,
118
signal strength calibration,
121–123
radar cross section
See (RCS)
Radar Data Processor,
253
Radar Directive File,
258
correlation times and,
338
dependence of ground clutter on,
209–211
insensitivity of distribution shape to,
419
Weibull mean strength and,
418
radar spatial resolution,
27
effects on spread in clutter amplitude distributions,
413
ensemble amplitude distributions and,
110–111
Weibull shape parameter and,
418
as discrete clutter sources,
115
correlation coefficient,
341
thresholding process for,
118
dependence of clutter strength on,
216–221
windblown clutter spectra for,
615–616
ratio of standard deviation-to-mean,
222
voltage distribution,
412,
416
RCS (radar cross section),
discrete sources of clutter and,
Regina Plain, Saskatchewan,
193
Booker Mountain, Nevada,
202
diurnial variability and,
235
Gull Lake West, Manitoba,
155
mean strength vs polarization,
212–215
terrain classification in,
158
RF (radio frequency),
154
Rosetown, Saskatchewan,
82
repeat sector measurements,
194
clutter modeling for,
545
rural/high-relief terrain
clutter strength vs depression angle,
296
depression angle distributions for,
68–70
overall amplitude distribution in,
75–77
clutter amplitude distributions,
100
clutter strength vs depression angle,
296
depression angle distributions for,
68–70
overall amplitude distribution in,
75–77
S
sampling populations,
425
SAR (synthetic aperture radar),
106
image data compression in,
291
mean clutter strength vs polarization at,
213
mean clutter strengths at,
185
oscillatory motions in,
642
clutter strength from steep forest at,
166
effects on ground clutter strength of,
231–234
SEKE propagation code,
262
sensitivity time control.
See STC
clutter strength for,
319
statistical attributes of,
384
vs radar sensitivity,
377
multifrequency clutter measurements at,
195–197
land clutter coefficients,
518
signal-to-interference power ratio,
621
signal-to-noise ratio,
254
effect on terrain visibility of,
360–364
site-specific clutter model,
307
soil, moisture content of,
234
space-time adaptive processing
See (STAP)
space-time correlation coefficient,
626
spatial amplitude distributions,
for general terrain types,
68–70
parametric dependence in,
115
vs signal-strength threshold,
spatial occupancy map,
18
in clutter histograms,
422
Doppler velocity and,
668
effects of tree species on,
598–600
invariance with radar frequency,
594–597
invariance with radar polarization,
597–598
variations with wind speed,
589–594
in amplitude statistics,
413
STALO (stable local oscillator),
672
standard deviation-to-mean ratio,
222–227
in clutter histograms,
422
Weibull shape parameter and,
417
STAP (space-time adaptive processing),
23
effect of windblown clutter on,
625–629
statistical clutter amplitude distributions,
23
statistical estimation theory,
100
sampling populations,
425
STC (sensitivity time control),
253,
329
stereo aerial photographs,
37,
396
overlaying clutter maps onto,
46
clutter strength vs range,
327
discrete clutter sources at,
325–330
repeat sector clutter measurements at,
330
sum of squared deviations,
136
surface-area density function,
survival wind velocity,
247
synthetic aperture radar.
See SAR
T
as clutter sources,
58,
216
in range calibration of radars,
120
temporal correlation coefficient,
626
in windblown clutter spectra,
598
classification system,
243
clutter strength vs frequency,
168
effects on illumination,
259
geometric visibility of,
359
land clutter coefficients,
429
microwave backscatter from,
111–114
negative depression angle,
94–95
reflection coefficients,
44,
260
subcategorization of,
294
variability within class,
243
depression angle and,
415
terrain reflection coefficients,
44
effects on ground clutter distributions,
371–379
from topographic contour maps,
192
patch classification by,
65
terrain visibility,
51,
312
effects of varying mast heights on,
360–364
effects of varying site heights on,
360–364
overlaying clutter maps onto,
46
traveling wave tubes,
251
as discrete clutter source,
115
effects on low-angle clutter,
91–93
in spatial resolution cells,
62
wind-induced motion of,
575
clutter strengths at,
211
W
clutter strength vs depression angle at,
356
clutter strength vs frequency at,
149
LCE clutter spectral measurements at,
584
repeat sector measurements at,
172–174
high-range resolution,
228
low-range resolution,
228
effects on ground clutter strength,
231–234
Weibull clutter model,
543
Weibull cumulative distribution function,
71,
134,
416
Weibull median strength,
72
Weibull probability density function
Weibull probability distribution
mean-to-median ratio,
134
ratio of mean-to-median in,
549
ratio of standard deviation-to-mean,
549
ratio of variance to the square of the mean in,
549
standard deviation-to-mean ratio,
134
Weibull shape parameter, ,
20,
72
radar spatial resolution and,
418,
433
standard deviation-to-mean ratio and,
417
vs radar spatial resolution,
295
in probability distributions,
544
mean-to-median ratio for,
72,
416
clutter amplitude distributions,
526
vs level forest clutter,
91
dielectric constant of,
234
effect on STAP (space-time adaptive processing),
625–629
regions of spectral approximation,
606–609
spectra vs radar frequency,
594–597
spectral measurements of,
582
spectral shape vs radar polarization,
597–598
windblown clutter spectra
Doppler velocity extent of,
579
effects of system instabilities on,
672
effects of tree species on,
598–600
impact on MTI filter performance,
621–623
invariance with radar frequency of,
594–597
spatial resolutions cells with,
576–582
X-band clutter spectra for,
671–672
Wolseley, Saskatchewan,
442
farmland clutter data from,
340
repeat sector measurements at,
194
X-band clutter measurements at,
563–573