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The azimuthal resolution (better known as crossrange resolution) depends on the beamwidth of the radar antenna. It is derived from the ratio of the physical size of the antenna (the real aperture) to the wavelength used. By the spreading of the beam it is also dependent on the slant range.
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The range resolution (the ability to separate the pixels of the image perpendicular to the direction of flight) of a SLAR depends on the length of the transmitted pulse. At the ground of Earth the range resolution has an inverse relationship with the depression angle:
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It is apparent that SLAR antennas as real aperture could not be built large enough to achieve the desired azimuth resolution. In fact, SLAR was never feasible to be used in space because the antennas would be too large and their launch in space too expensive.
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For the approximation of a flat earth – which is usual for airborne radar with short to medium range – the grazing angle and the depression angle can be assumed to be equal
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229:.) The antenna illuminates an area, the so-called footprint. The direction of the incoming wave relative to the horizontal plane may be measured also. This angle
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between the x-axis and the projection of the line of sight to the (x; y)-plane is called azimuth angle. Cone- and azimuth angle are related by cos
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183:(nonperpendicular) mode is also possible. SLAR can be fitted with a standard antenna (real aperture radar) or an antenna using
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with respect to the vertical axis at this point. (In some publications the incident angle is denominated to as
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and the highest the range resolution, but the lower the echo signal. This limitation can be overcome using
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324:(in the figures shown as a red arrow) pointing from the antenna to a ground scatterer. The variables
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The platform of the radar moves in direction of the x-axis. The radar "looks" with the looking angle
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741:{\displaystyle \delta _{Az}={\frac {\rho \lambda }{2L}}={\frac {H\lambda }{L\sin \gamma }}}
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245: + 90° is used for a mathematical description in a spherical coordinate system.
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This article is about the imaging radar. For the rugby union competition also known as
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as the azimuth angle between the line of sight and the x-axis (direction of flight).
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refers to a method for improving the azimuth resolution (not range resolution).
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between x-axis and the line of sight (LOS) is called cone angle, the angle
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are directional cosines with respect to the x; y; z axes. The variable
444:= duration of the (may be compressed in matched receiver) radar pulse
880:"Side-Looking Airborne Radar (SLAR) Mosaics | The Long Term Archive"
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412:{\displaystyle \delta _{g}={\frac {\tau c_{0}}{2\cos \gamma }}}
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pointing perpendicular to the direction of flight (hence
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68:. Unsourced material may be challenged and removed.
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144:Definition of angles in the vertical plane of SLAR
599:. Using a step-frequency waveform of bandwidth
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264:. The so-called LOS-vector is a unit vector
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795:= antenna length (in direction of flight)
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128:Learn how and when to remove this message
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171:) is an aircraft- or satellite-mounted
317:{\displaystyle {\vec {u}}=(u,v,w)^{t}}
521:is typically 0.4 ... 1 μs, i.e.
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647:{\displaystyle \delta _{r}=c_{0}/2B}
66:adding citations to reliable sources
237:is called grazing angle. The angle
658:Azimuthal resolution (along track)
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160:SLAR radar at ILA Berlin Air Show
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348:Range resolution (across track)
53:needs additional citations for
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260: = 180° –
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77:"Side looking airborne radar"
33:Súper Liga Americana de Rugby
588:{\displaystyle \delta _{g}}
541:{\displaystyle \delta _{g}}
165:Side-looking airborne radar
18:Side-looking airborne radar
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256:and the incident angle is
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937:Synthetic aperture radar
848:Synthetic aperture radar
839:= height of the platform
766:{\displaystyle \lambda }
603:the range resolution is
488:{\displaystyle \gamma }
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561:{\displaystyle \tau }
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866:Notes and references
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62:improve this article
912:"A Sideways Glance"
152:Geometry of an SLAR
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495:= depression angle
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198:angle). The angle
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832:{\displaystyle H}
788:{\displaystyle L}
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79: –
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73:Find sources:
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51:This article
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887:. Retrieved
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773:= wavelength
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177:side-looking
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60:Please help
55:verification
52:
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926:Categories
889:2018-02-25
568:the lower
88:newspapers
805:ρ
761:λ
733:γ
730:
719:λ
696:λ
693:ρ
675:δ
612:δ
577:δ
556:τ
530:δ
509:τ
483:γ
432:τ
404:γ
401:
380:τ
365:δ
278:→
118:June 2015
854:See also
181:squinted
914:a 1966
326:u, v, w
102:scholar
916:Flight
104:
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31:, see
340:with
196:nadir
179:). A
109:JSTOR
95:books
169:SLAR
81:news
29:SLAR
727:sin
398:cos
332:is
64:by
928::
882:.
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187:.
892:.
827:H
783:L
724:L
716:H
710:=
704:L
701:2
687:=
682:z
679:A
642:B
639:2
635:/
629:0
625:c
621:=
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601:B
581:g
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342:α
338:α
334:u
330:u
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302:w
299:,
296:v
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290:u
287:(
284:=
275:u
262:θ
258:β
254:ε
250:γ
243:ε
239:θ
235:β
231:γ
226:i
224:θ
220:β
216:ε
212:φ
208:α
204:φ
200:α
192:θ
167:(
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125:(
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116:(
106:·
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