CONICAL SCAN WEATHER RADAR
A new measurement approach is disclosed that facilitates significantly smaller size, weight, and power (SWaP) spaceborne radar systems that can provide wide swath, high resolution observations. Multiple beams employed in the scan and the complex volume and/or surface backscatter signals of each beam is recorded. Each beam is electronically swept in azimuth where each beam is held at a constant incidence angle over the azimuth sector that covers the swath. Once the sweep is complete, the platform moves forward, by one along track pixel, and the sweep is repeated in order to provide continuous mapping of the volume and surface covered by the swath. Complex volume backscatter is recorded and mapped to each altitude layer to provide full mapping of the atmosphere.
1 . A method comprising:
causing an electronically steerable radar array suspended above a surface at a high elevation to generate, on a common scan pass, at least a first pencil beam having a first direction and a second pencil beam having a second direction different from the first direction, including indexing each of the first and second pencil beams generated by said electronically steerable radar array to define points on a grid having a cross track perpendicular to a direction of travel of said radar array and an along track in line with said direction of travel of said radar array;
causing the electronically steerable radar array to independently direct the first pencil beam and the second pencil beam at respective fixed incidence angles along at least one scan path that sweeps across said cross track and illuminates the points on the grid; causing the electronically steerable radar array to receive first pencil beam return signals and second pencil beam return signals, the received first pencil beam return signals and second pencil beam return signals comprising combinations of atmospheric layer return signals and surface return signals; and
causing processing of the received first pencil beam return signals and second pencil beam return signals to generate information based on combinations of atmospheric layer return signals and surface return signals.
2 . The method of claim 1 further including at least one digital signal processor using the generated information to enable observation of at least one of an atmospheric layer and the surface.
3 . The method of claim 1 wherein the return signals represent backscatter.
4 . The method of claim 1 wherein the radar array is suspended on a satellite platform.
5 . The method of claim 1 wherein the generated information indicates one or more weather conditions.
6 . The method of claim 1 wherein the generated information is based on multiple samples on return signals separated from each of the first pencil beam and the second pencil beam.
7 . The method of claim 1 further including mapping an aspect of the return signals to an atmospheric altitude layer.
8 . The method of claim 7 further including using the return signals to provide a complete mapping of a scanned volume.
9 . The method of claim 1 further causing the electronically steerable radar array to perform multiple scans of said first and second pencil beams on the same scan pass.
10 . The method of claim 1 further including causing the electronically steerable radar array to perform multiple scans on multiple incidence and/or azimuth angles in different scan passes.
11 . The method of claim 1 wherein receiving comprises receiving multiple parameters representing observed weather conditions.
12 . The method of claim 1 wherein receiving comprises receiving multiple parameters representing observed surface processes.
13 . The method of claim 1 further including causing the radar array to scan a plurality of altitude slices with each of the first pencil beam and the second pencil beam.
14 . The method of claim 1 wherein the return signals provide samples of one or more selected altitude slices based at least in part on separation of returned backscatter signal(s) from each of the first pencil beam and the second pencil beam.
15 . The method of claim 1 further comprising separating atmospheric layer return signals from surface return signals.
16 . A method comprising:
causing an electronically steerable radar array suspended above a surface at a high elevation to generate, on a first scan pass, to direct a first pencil beam along a first, fixed incident angle along at least one scan path that sweeps across a cross track perpendicular to a direction of travel of said radar array and an along track in line with said direction of travel of said radar array, and illuminates points on a grid;
causing the electronically steerable radar array suspended above the surface at the high elevation to generate, on a second scan pass different from the first scan pass, to direct a second pencil beam at a second, fixed incident angle different from the first, fixed incident angle along the at least one scan path that sweeps across the cross track perpendicular to the direction of travel of said radar array and the along track in line with said direction of travel of said radar array, and illuminates additional points on the grid;
causing the electronically steerable radar array to receive first pencil beam return signals and second pencil beam return signals, the received first pencil beam return signals and second pencil beam return signals each comprising a combination of atmospheric layer return signals and surface return signals; and
causing processing of the received first pencil beam return signals and second pencil beam return signals to generate information based on combinations of atmospheric layer return signals and surface return signals.
17 . The method of claim 16 further including at least one digital signal processor using the generated information to enable observation of an atmospheric layer and/or the surface.
18 . The method of claim 16 wherein the return signals represent backscatter.
19 . The method of claim 16 wherein the radar array is suspended on a satellite platform.
20 . The method of claim 16 wherein the generated information indicates one or more weather conditions.
21 . The method of claim 16 wherein the generated information is based on multiple samples on return signals separated from each of the first pencil beam and the second pencil beam.
22 . The method of claim 16 further including mapping an aspect of the return signals to an atmospheric altitude layer.
23 . The method of claim 22 further including using the return signals to provide a complete mapping of a scanned volume.
24 . The method of claim 16 further causing the electronically steerable radar array to perform multiple scans of each of said first and second pencil beams.
25 . The method of claim 16 further including causing the electronically steerable radar array to perform multiple scans on multiple incidence and/or azimuth angles in different scan passes.
26 . The method of claim 16 wherein receiving comprises receiving multiple parameters representing observed weather conditions.
27 . The method of claim 16 wherein receiving comprises receiving multiple parameters representing observed surface processes.
28 . The method of claim 16 further including causing the radar array to scan a plurality of altitude slices with each of the first pencil beam and the second pencil beam.
29 . The method of claim 16 wherein the return signals provide samples of one or more selected altitude slices based at least in part on separation of returned backscatter signal(s) from each of the first pencil beam and the second pencil beam.
30 . The method of claim 16 further comprising separating atmospheric layer return signals from surface return signals.