TELESCOPE WITH A WIDE FIELD OF VIEW INTERNAL OPTICAL SCANNER

• US 20110051121A1
• Filed: 08/25/2009
• Published: 03/03/2011
• Est. Priority Date: 08/25/2009
• Status: Active Grant

• Current Assignee: Intergraph Corporation (Hexagon AB)
• Original Assignee: Sigma Space Corp. (Hexagon AB)
• Inventors: Degnan, John James III, Zheng, Yunhui
• Granted Patent: US 8,144,312 B2
• Time in Patent Office: Days
• US Class Current: 356/5.05
• CPC Class Codes: G01C 3/04 Adaptation of rangefinders for combination with telescopes or binoculars
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/0208 using focussing or collimating elements, e.g. lenses or mirrors; performing aberration correction
• CPC Class Codes: G01J 3/0224 using polarising or depolarising elements
• CPC Class Codes: G01J 3/36 Investigating two or more bands of a spectrum by separate detectors
• CPC Class Codes: G02B 23/06 having a focussing action, e.g. parabolic mirror
• CPC Class Codes: G02B 23/14 Viewfinders for photographic apparatus G03B13/02
• CPC Class Codes: G02B 26/108 having one or more prisms as scanning elements
• CPC Class Codes: H01L 27/14601 Structural or functional details thereof
• CPC Class Codes: H01L 27/14625 Optical elements or arrangements associated with the device

Abstract

A telescope with internal scanner utilizing either a single optical wedge scanner or a dual optical wedge scanner and a controller arranged to control a synchronous rotation of the first and/or second optical wedges, the wedges constructed and arranged to scan light redirected by topological surfaces and/or volumetric scatterers. The telescope with internal scanner further incorporates a first converging optical element that receives the redirected light and transmits the redirected light to the scanner, and a second converging optical element within the light path between the first optical element and the scanner arranged to reduce an area of impact on the scanner of the beam collected by the first optical element.

Claims

1. A telescope with internal scanner comprising:

a wedge optical scanner comprising a first optical wedge and a controller arranged to control a synchronous rotation of the first optical wedge, the wedge being constructed and arranged to scan light redirected by topological surfaces and/or volumetric scatterers;

a first converging optical element that receives the redirected light and transmits the redirected light to the scanner; and

a second converging optical element within the light path between the first optical element and the scanner arranged to reduce an area of impact on the scanner of the beam collected by the first optical element.

2. The telescope with internal scanner of claim 1, the wedge optical scanner further comprising a second optical wedge, wherein the controller is arranged to synchronize the rotation of the first and second optical wedge to a laser pulse rate.

3. The telescope with internal scanner of claim 2 wherein the synchronization of the rotation of the wedges is achieved utilizing laser pulses rate as a clock oscillator frequency.

5. The telescope with internal scanner of claim 2 wherein the laser pulse rate is between 8 kHz and 30 kHz.

6. The telescope with internal scanner of claim 1, wherein the telescope further comprises a primary converging optical element.

7. The telescope with internal scanner of claim 6, wherein the primary converging optical element is a converging mirror.

8. The telescope with internal scanner of claim 7, wherein the telescope further comprises a secondary mirror.

9. The telescope with internal scanner of claim 8, wherein the primary and secondary mirrors are constructed and arranged to form a Cassegrain configuration.

10. The telescope with internal scanner of claim 9, wherein the Cassegrain configuration is chosen from a group of Cassegrain configurations consisting of:

classic Cassegrain, Schmidt-Cassegrain, Maksutov-Cassegrain, Argunov-Cassegrain, Ritchey-Chré

tien, and Dall-Kirkham.

11. The telescope with internal scanner of claim 7, wherein the converging mirror is an off-axis primary mirror.

12. The telescope with internal scanner of claim 11, wherein the off-axis primary mirror is an off-axis parabolic primary mirror.

13. The telescope with internal scanner of claim 11, further comprising at least one secondary mirror wherein the off-axis primary and the secondary mirrors are constructed and arranged to form a configuration chosen from a group of configurations consisting of:

Schiefspiegler, Yolo, Multi-Schiefspiegler, and multi-mirror Yolo configurations.

14. The telescope with internal scanner of claim 1, wherein the telescope has a linear aperture smaller than 200 cm.

15. The telescope with internal scanner of claim 1, wherein the telescope has a linear aperture smaller than 100 cm.

16. The telescope with internal scanner of claim 1, wherein the telescope has a linear aperture smaller than 50 cm.

17. The telescope with internal scanner of claim 1, wherein the optical dual wedge scanner is constructed and arranged to simultaneously scan light emitted by a laser and the light redirected by topological surfaces and/or volumetric scatterers.

18. The telescope with internal scanner of claim 1, wherein the optical dual wedge scanner is positioned coaxially adjacent to the second converging optical element on the opposite side of the second converging optical element relative to the side of the converging optical element where the first converging optical element is positioned.

19. The telescope with internal scanner of claim 1, wherein the optical dual wedge scanner has a wedge diameter smaller than a linear aperture of the telescope.

4. The telescope with internal scanner of 2 wherein the laser pulse rate is in the kilohertz range.

20. The telescope with internal scanner 1, wherein the optical dual wedge scanner has the wedge diameter smaller than 10% of a linear aperture of the telescope.

21. The telescope with internal scanner 1, wherein the optical dual wedge scanner has the wedge diameter smaller than 25% of a linear aperture of the telescope.

22. The telescope with internal scanner 1, wherein the dual wedge optical scanner has the wedge diameter smaller than 50% of a linear aperture of the telescope.

23. A 3D imaging system comprising:

a light source that can emit a beam of light;

a telescope with internal scanner comprising;

an optical wedge scanner comprising a first optical wedge and a controller arranged to control a synchronous rotation of the first optical wedge, the wedge being constructed and arranged to scan light redirected by topological surfaces and/or volumetric scatterers;

a first converging optical element that receives the redirected light and transmits the redirected light to the scanner; and

a second converging optical element within the light path between the first optical element and the scanner arranged to reduce an area of impact on the scanner of the beam transmitted by the first optical element;

a detector module arranged to detect light collected by the telescope and generate signals responsive to the detected light; and

a processor constructed to process signals generated by the detector.

24. The imaging LIDAR/Polarimeter of claim 23, the optical wedge scanner further comprising a second optical wedge, wherein the light source is a pulsed laser and the controller is arranged to synchronize the rotation rates of the first and second optical wedges to the laser pulse rate.

25. The imaging LIDAR/Polarimeter of claim 24, wherein the laser is a frequency-doubled Nd:

YAG laser that transmits a laser beam containing photons having substantially a wavelength of the principle Nd;

YAG laser transitions and frequency-doubled photons having substantially a wavelength of one half of the wavelength of the principle Nd;

YAG laser transitions.

26. The imaging LIDAR/Polarimeter of claim 24, further comprising a laser start detector arranged to detect start times of each laser pulse and provide the start times data to the controller.

27. The imaging LIDAR/Polarimeter of claim 23, wherein the optical dual wedge scanner is constructed and arranged to simultaneously scan light emitted by the light source and the light redirected by topological surfaces and/or volumetric scatterers.

28. The imaging LIDAR/Polarimeter of claim 24, further comprising a laser beam expander arranged to expand the diameter of the laser beam.

29. The imaging LIDAR/Polarimeter of claim 24, further comprising a laser beam dividing device arranged to divide the laser beam into an array of substantially equal energy beamlets.

30. The imaging LIDAR/Polarimeter of claim 29, where the laser beam dividing device is a diffractive beam dividing device.

31. The imaging LIDAR/Polarimeter of claim 29, where the laser beam dividing device is a Holographic Optical Element (HOE).

32. The imaging LIDAR/Polarimeter of claim 23, further comprising an annular mirror arranged to selectively transmit light emitted by the pulsed laser and to reflect the light collected by the telescope toward the detector module.

33. The imaging LIDAR/Polarimeter of claim 23, wherein the detector module comprises a 3D imaging leg and a polarimeter leg.

34. The imaging LIDAR/Polarimeter of claim 33, wherein the 3D imaging leg comprises a dichroic beam splitter arranged to separate components of collected light into a 3D imaging beamlets comprising the frequency-doubled photons and a polarimetry beam comprising the photons with wavelength substantially equal to the wavelength of the principle Nd:

YAG laser transitions.

35. The imaging LIDAR/Polarimeter of claim 33, wherein the 3D imaging leg and the polarimeter leg comprise a spectral filters and a spatial filters constructed and arranged to reduce the noise background seen by the detectors.

36. The imaging LIDAR/Polarimeter of claim 33, wherein the 3D imaging leg further comprises a Dove prism constructed and arranged to adjust azimuthal positions of the beamlets with respect to the optical axis of the 3D imaging leg.

37. The imaging LIDAR/Polarimeter of claim 33, wherein the 3D imaging leg further comprises a multichannel photodetector, Dove prism, and a telephoto lens assembly constructed and arranged to spatially match the beamlets to individual pixels of the multichannel photodetector.

38. The imaging LIDAR/Polarimeter of claim 37, wherein the multichannel photodetector is chosen from the set of multichannel photodetectors consisting of photodiodes and photodiode arrays, PIN diodes and PIN diode arrays, phototransistors and phototransistor arrays, CCD and CMOS photodetector arrays.

39. The imaging LIDAR/Polarimeter of claim 37, wherein the multichannel photodetector is a multi-anode photomultiplier.

40. The imaging LIDAR/Polarimeter of claim 37, wherein the multichannel photodetector is a microchannel plate photomultiplier.

41. The imaging LIDAR/Polarimeter of claim 33, wherein the polarimeter leg further comprises a polarizer and at least two photodetectors constructed and arranged to detect the depolarization of the photons having the wavelength substantially equal to the wavelength of the principal Nd:

YAG laser transition.

42. The imaging LIDAR/Polarimeter of claim 23 further comprising a transmitter optical dual wedge scanner comprising a first optical wedge, a second optical wedge.

43. The imaging LIDAR/Polarimeter of claim 42 where the telescope with internal scanner is arranged and positioned such that any optical component of the telescope does not intersect or focus the transmitter laser beam.

44. The imaging LIDAR/Polarimeter of claim 42 where the telescope with internal scanner is arranged such that backscatter of the transmitter laser beam light into the detector module is substantially eliminated.

45. The imaging LIDAR/Polarimeter of claim 42 wherein the controller is arranged to synchronize the rotation of the first and second optical wedges of the optical dual wedge scanner and the transmitter optical dual wedge scanner to a laser pulse rate.

46. The imaging LIDAR/Polarimeter of claim 42 further comprising a transmitter beam expander constructed and arranged to expend the diameter of a laser beam impacting the transmitter optical dual wedge scanner.