Jitter - Revision history

Lwcamp at 19:02, 7 March 2026

2026-03-07T19:02:52Z

← Older revision		Revision as of 12:02, 7 March 2026
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	==References==		==References==

	[[Category:Lasers]][[Category:Beams]][[Category:Physics & Engineering‏‎]]		[[Category:Lasers]][[Category:Beams]][[Category:Physics & Engineering‏‎]][[Category:Physics & Math & Engineering]]

Lwcamp: /* All that ugly math */

2025-09-20T22:27:29Z

All that ugly math

← Older revision		Revision as of 15:27, 20 September 2025
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	S ≈ R σ.		S ≈ R σ.
	</div>		</div>
	If your target ~~has~~ a profile area A in your view, your chance of hitting with a single shot will be approximately		If S is much smaller than the cross sectional dimensions of your target in your field of view, jitter is unimportant to the problem of hitting your target. If the jitter is much larger than the dimensions of your target hitting becomes a matter of probability. For a target with a profile area A in your view, your chance of hitting with a single shot when the jitter S is much larger than your target will be approximately
	<div class="center" style="width: auto; margin-left: auto; margin-right: auto;">		<div class="center" style="width: auto; margin-left: auto; margin-right: auto;">
	p ≈ 4 A / (π S²).		p ≈ 4 A / (π S²).

Lwcamp: /* How much jitter? */

2025-07-23T01:55:39Z

How much jitter?

← Older revision		Revision as of 18:55, 22 July 2025
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	==How much jitter?==		==How much jitter?==

	How much of a problem is jitter, really? The angle base motion disturbance of satellites in orbit tend to be around a few tens of microradians (a few times 10<sup>-6</sup> radians)<ref name="ADA464385">[https://apps.dtic.mil/sti/citations/ADA464385 J. Negro and S. Griffin, "Inertially Stabilized Platforms for Precision Pointing: Applications to directed-energy weapons and space-based lasers", US Government report ADA464385, Aug 17 2006]</ref>, while for aircraft in flight it can be closer to a few hundred microradians<ref name="ADA464385"></ref>. If this is not corrected, this is the jitter a weapons system will have to deal with. Fortunately, there are ways to stabilize weapons mounts and reduce the native jitter of the parent vehicle<ref name="ADA464385"></ref>. As of 2006, a stable platform jitter reduction system can reduce the jitter by at least 42 dB (four orders of magnitude), and potentially more depending on the primary frequencies where the jitter is occurring<ref name="ADA464385"></ref>.		How much of a problem is jitter, really? The angle base motion disturbance of satellites in orbit tend to be around a few tens of microradians (a few times 10<sup>-5</sup> radians)<ref name="ADA464385">[https://apps.dtic.mil/sti/citations/ADA464385 J. Negro and S. Griffin, "Inertially Stabilized Platforms for Precision Pointing: Applications to directed-energy weapons and space-based lasers", US Government report ADA464385, Aug 17 2006]</ref>, while for aircraft in flight it can be closer to a few hundred microradians<ref name="ADA464385"></ref>. If this is not corrected, this is the jitter a weapons system will have to deal with. Fortunately, there are ways to stabilize weapons mounts and reduce the native jitter of the parent vehicle<ref name="ADA464385"></ref>. As of 2006, a stable platform jitter reduction system can reduce the jitter by at least 42 dB (four orders of magnitude), and potentially more depending on the primary frequencies where the jitter is occurring<ref name="ADA464385"></ref>.

	We can look at modern telescopes for more information on the extent to which jitter affects directed energy weapons, because a telescope is really just a laser beam pointer operating in reverse. What we see is that for visible and near-visible colors of light, you can put in enough work to get the jitter angles close enough to the limits imposed by diffraction or turbulence that they are no longer a problem<ref name="Keck Telescope and Facility Instrument Guide">[https://www2.keck.hawaii.edu/observing/kecktelgde/ktelinstupdate.pdf Keck Telescope and Facility Instrument Guide]</ref><ref name="HST pointing control">[https://www.nasa.gov/content/goddard/hubble-space-telescope-pointing-control-system Hubble Space Telescope: Observatory - Pointing Control]</ref><ref name="Bely_May">[https://www.sciencedirect.com/science/article/pii/S1474667017496881 P.Y.Bély and B.S.May, "The Pointing Stability of the Hubble Space Telescope and Proposed Concepts for the Pointing Control of the Next Generation Space Telescope (NGST)", IFAC Proceedings Volumes, Volume 25, Issue 22, September 1992, Pages 457-462]</ref><ref name="ELT">Cédric Plantet, Benoît Neichel, Guido Agapito, Lorenzo Busoni, Carlos M. Correia, Thierry Fusco, Marco Bonaglia, and Simone Esposito, "Sky coverage assessment for the European ELT: a joint evaluation for MAORY/MICADO and HARMONI", Journal of Astronomical Telescopes, Instruments, and Systems, Vol. 8, Issue 2, 021509 (May 2022). https://doi.org/10.1117/1.JATIS.8.2.021509</ref><ref name="JWST">[https://jwst-docs.stsci.edu/jwst-observatory-characteristics/jwst-pointing-performance JWST Pointing Performance]</ref>.		We can look at modern telescopes for more information on the extent to which jitter affects directed energy weapons, because a telescope is really just a laser beam pointer operating in reverse. What we see is that for visible and near-visible colors of light, you can put in enough work to get the jitter angles close enough to the limits imposed by diffraction or turbulence that they are no longer a problem<ref name="Keck Telescope and Facility Instrument Guide">[https://www2.keck.hawaii.edu/observing/kecktelgde/ktelinstupdate.pdf Keck Telescope and Facility Instrument Guide]</ref><ref name="HST pointing control">[https://www.nasa.gov/content/goddard/hubble-space-telescope-pointing-control-system Hubble Space Telescope: Observatory - Pointing Control]</ref><ref name="Bely_May">[https://www.sciencedirect.com/science/article/pii/S1474667017496881 P.Y.Bély and B.S.May, "The Pointing Stability of the Hubble Space Telescope and Proposed Concepts for the Pointing Control of the Next Generation Space Telescope (NGST)", IFAC Proceedings Volumes, Volume 25, Issue 22, September 1992, Pages 457-462]</ref><ref name="ELT">Cédric Plantet, Benoît Neichel, Guido Agapito, Lorenzo Busoni, Carlos M. Correia, Thierry Fusco, Marco Bonaglia, and Simone Esposito, "Sky coverage assessment for the European ELT: a joint evaluation for MAORY/MICADO and HARMONI", Journal of Astronomical Telescopes, Instruments, and Systems, Vol. 8, Issue 2, 021509 (May 2022). https://doi.org/10.1117/1.JATIS.8.2.021509</ref><ref name="JWST">[https://jwst-docs.stsci.edu/jwst-observatory-characteristics/jwst-pointing-performance JWST Pointing Performance]</ref>.

Lwcamp: /* All that ugly math */

2025-04-08T23:15:16Z

All that ugly math

← Older revision		Revision as of 16:15, 8 April 2025
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	==All that ugly math==		==All that ugly math==

	If you know the amount of jitter ~~<math>\sigma_j</math>~~ of your beam pointer in radians, at a range of ~~<math>~~R~~</math>~~ the diameter of the spot your beam will wander over is		If you know the amount of jitter σ of your beam pointer in radians, at a range of R the diameter of the spot your beam will wander over is
	<div class="center" style="width: auto; margin-left: auto; margin-right: auto;"~~><math~~>		<div class="center" style="width: auto; margin-left: auto; margin-right: auto;">
	~~S_j~~ = 2 \, R ~~\, \~~tan(~~\sigma_j~~/2).		S = 2 R tan(σ/2).
	~~</math>~~</div>		</div>
	For small jitter angles (and if your weapon is going to be at all useful, the angles had better be small), this is approximately		For small jitter angles (and if your weapon is going to be at all useful, the angles had better be small), this is approximately
	<div class="center" style="width: auto; margin-left: auto; margin-right: auto;"~~><math~~>		<div class="center" style="width: auto; margin-left: auto; margin-right: auto;">
	~~S_j \approx~~ R ~~\, \sigma_j~~.		S ≈ R σ.
	~~</math>~~</div>		</div>
	If your target has a profile area ~~<math>~~A~~</math>~~ in your view, your chance of hitting with a single shot will be approximately		If your target has a profile area A in your view, your chance of hitting with a single shot will be approximately
	<div class="center" style="width: auto; margin-left: auto; margin-right: auto;"~~><math~~>		<div class="center" style="width: auto; margin-left: auto; margin-right: auto;">
	p ~~\approx \frac{~~A}{(~~\pi/4~~) ~~\, S_j^2}~~.		p ≈ 4 A / (π S²).
	~~</math>~~</div>		</div>

	If you have an acceptable probability of hit ~~<math>~~p~~</math>~~ you're willing to begin firing at a target with profile area ~~<math>~~A~~</math>~~, then the range at which you may fire when ready is approximately:		If you have an acceptable probability of hit p you're willing to begin firing at a target with profile area A, then the range at which you may fire when ready is approximately:
	<div class="center" style="width: auto; margin-left: auto; margin-right: auto;"~~><math~~>		<div class="center" style="width: auto; margin-left: auto; margin-right: auto;">
	R ~~\approx \sqrt{\frac{~~A~~}{(\pi~~/~~4) \,~~ (~~\sigma_j)^2 \,~~ p~~} } = \sqrt{\frac{4 \times A}{\pi \, p\, (\sigma_j~~)~~^2 } }~~.		R ≈ √[4 A / (π p σ²) ].
	~~</math>~~</div>		</div>

	==Credit==		==Credit==

Lwcamp: /* How much jitter? */

2025-03-23T22:56:52Z

How much jitter?

← Older revision		Revision as of 15:56, 23 March 2025
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	<table border=1>		<table border=1>
	<tr><td> Instrument <td> Jitter (radians)		<tr><td> Instrument <td> Jitter (radians)
	<tr><td> Keck Telescope <td~~> <math~~>3.9\times 10^{-7}</~~math~~><ref name="Keck Telescope and Facility Instrument Guide"></ref>		<tr><td> Keck Telescope <td> 3.9 × 10<sup>-7</sup><ref name="Keck Telescope and Facility Instrument Guide"></ref>
	<tr><td> Hubble Space Telescope <td~~> <math~~>3.4\times 10^{-8}</~~math~~><ref name="HST pointing control"></ref><ref name="Bely_May"></ref>		<tr><td> Hubble Space Telescope <td> 3.4 × 10<sup>-8</sup><ref name="HST pointing control"></ref><ref name="Bely_May"></ref>
	<tr><td> James Webb Space Telescope <td~~> <math~~>4.8\times 10^{-9}</~~math~~><ref name="JWST"></ref>		<tr><td> James Webb Space Telescope <td> 4.8 × 10<sup>-9</sup><ref name="JWST"></ref>
	<tr><td> Extremely Large Telescope (predicted) <td~~> <math~~>5 \times 10^{-8}</~~math~~> – ~~<math>~~1 \times 10^{-8}</~~math~~><ref name="ELT"></ref>		<tr><td> Extremely Large Telescope (predicted) <td> 5 × 10<sup>-8</sup> – 1 × 10<sup>-8</sup><ref name="ELT"></ref>
	<tr><td> Stratospheric Observatory for Infrared Astronomy (SOFIA) <td~~> <math~~>1.0 \times 10^{-5}</~~math~~> – ~~<math>~~2.0 \times 10^{-6}</~~math~~><ref name="SOFIA Observer's Handbook"></ref><ref name="simulating SOFIA"></ref>		<tr><td> Stratospheric Observatory for Infrared Astronomy (SOFIA) <td> 1.0 × 10<sup>-5</sup> – 2.0 × 10<sup>-6</sup><ref name="SOFIA Observer's Handbook"></ref><ref name="simulating SOFIA"></ref>
	<tr><td> Boeing YAL-1 <td~~> <math~~>1.0 \times 10^{-6}</~~math~~><ref>[https://apps.dtic.mil/sti/citations/ADA451655 Roger M. Glaese, Eric H. Anderson, and Paul C. Janzen, "Active Suppression of Acoustically Induced Jitter for the Airborne Laser" ADA451655]</ref>		<tr><td> Boeing YAL-1 <td> 1.0 × 10<sup>-6</sup><ref>[https://apps.dtic.mil/sti/citations/ADA451655 Roger M. Glaese, Eric H. Anderson, and Paul C. Janzen, "Active Suppression of Acoustically Induced Jitter for the Airborne Laser" ADA451655]</ref>
	<tr><td> Space Integrated Controls Experiment (SPICE) <td~~> <math~~>2 \times 10^{-7}</~~math~~><ref name="SPICE Precision Pointing Experiment"></ref><ref name="SPICE Program"></ref>		<tr><td> Space Integrated Controls Experiment (SPICE) <td> 2 × 10<sup>-7</sup><ref name="SPICE Precision Pointing Experiment"></ref><ref name="SPICE Program"></ref>
	<tr><td> Space Active Vibration Isolation (SAVI) <td~~> <math~~>1 \times 10^{-7}</~~math~~><ref name="SAVI"></ref>		<tr><td> Space Active Vibration Isolation (SAVI) <td> 1 × 10<sup>-7</sup><ref name="SAVI"></ref>
	</table>		</table>

Lwcamp: /* How much jitter? */

2025-03-23T22:52:53Z

How much jitter?

← Older revision		Revision as of 15:52, 23 March 2025
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	==How much jitter?==		==How much jitter?==

	How much of a problem is jitter, really? We can look at modern telescopes for ~~some idea~~, because a telescope is really just a laser beam pointer operating in reverse. What we see is that for visible and near-visible colors of light, you can put in enough work to get the jitter angles close enough to the limits imposed by diffraction or turbulence that they are no longer a problem<ref name="Keck Telescope and Facility Instrument Guide">[https://www2.keck.hawaii.edu/observing/kecktelgde/ktelinstupdate.pdf Keck Telescope and Facility Instrument Guide]</ref><ref name="HST pointing control">[https://www.nasa.gov/content/goddard/hubble-space-telescope-pointing-control-system Hubble Space Telescope: Observatory - Pointing Control]</ref><ref name="Bely_May">[https://www.sciencedirect.com/science/article/pii/S1474667017496881 P.Y.Bély and B.S.May, "The Pointing Stability of the Hubble Space Telescope and Proposed Concepts for the Pointing Control of the Next Generation Space Telescope (NGST)", IFAC Proceedings Volumes, Volume 25, Issue 22, September 1992, Pages 457-462]</ref><ref name="ELT">Cédric Plantet, Benoît Neichel, Guido Agapito, Lorenzo Busoni, Carlos M. Correia, Thierry Fusco, Marco Bonaglia, and Simone Esposito, "Sky coverage assessment for the European ELT: a joint evaluation for MAORY/MICADO and HARMONI", Journal of Astronomical Telescopes, Instruments, and Systems, Vol. 8, Issue 2, 021509 (May 2022). https://doi.org/10.1117/1.JATIS.8.2.021509</ref><ref name="JWST">[https://jwst-docs.stsci.edu/jwst-observatory-characteristics/jwst-pointing-performance JWST Pointing Performance]</ref>.		How much of a problem is jitter, really? The angle base motion disturbance of satellites in orbit tend to be around a few tens of microradians (a few times 10<sup>-6</sup> radians)<ref name="ADA464385">[https://apps.dtic.mil/sti/citations/ADA464385 J. Negro and S. Griffin, "Inertially Stabilized Platforms for Precision Pointing: Applications to directed-energy weapons and space-based lasers", US Government report ADA464385, Aug 17 2006]</ref>, while for aircraft in flight it can be closer to a few hundred microradians<ref name="ADA464385"></ref>. If this is not corrected, this is the jitter a weapons system will have to deal with. Fortunately, there are ways to stabilize weapons mounts and reduce the native jitter of the parent vehicle<ref name="ADA464385"></ref>. As of 2006, a stable platform jitter reduction system can reduce the jitter by at least 42 dB (four orders of magnitude), and potentially more depending on the primary frequencies where the jitter is occurring<ref name="ADA464385"></ref>.

			We can look at modern telescopes for more information on the extent to which jitter affects directed energy weapons, because a telescope is really just a laser beam pointer operating in reverse. What we see is that for visible and near-visible colors of light, you can put in enough work to get the jitter angles close enough to the limits imposed by diffraction or turbulence that they are no longer a problem<ref name="Keck Telescope and Facility Instrument Guide">[https://www2.keck.hawaii.edu/observing/kecktelgde/ktelinstupdate.pdf Keck Telescope and Facility Instrument Guide]</ref><ref name="HST pointing control">[https://www.nasa.gov/content/goddard/hubble-space-telescope-pointing-control-system Hubble Space Telescope: Observatory - Pointing Control]</ref><ref name="Bely_May">[https://www.sciencedirect.com/science/article/pii/S1474667017496881 P.Y.Bély and B.S.May, "The Pointing Stability of the Hubble Space Telescope and Proposed Concepts for the Pointing Control of the Next Generation Space Telescope (NGST)", IFAC Proceedings Volumes, Volume 25, Issue 22, September 1992, Pages 457-462]</ref><ref name="ELT">Cédric Plantet, Benoît Neichel, Guido Agapito, Lorenzo Busoni, Carlos M. Correia, Thierry Fusco, Marco Bonaglia, and Simone Esposito, "Sky coverage assessment for the European ELT: a joint evaluation for MAORY/MICADO and HARMONI", Journal of Astronomical Telescopes, Instruments, and Systems, Vol. 8, Issue 2, 021509 (May 2022). https://doi.org/10.1117/1.JATIS.8.2.021509</ref><ref name="JWST">[https://jwst-docs.stsci.edu/jwst-observatory-characteristics/jwst-pointing-performance JWST Pointing Performance]</ref>.
	If your diffraction-limited spot size is 1 cm across, no one will care if the point of aim is jumping around by 3 mm or so. This is not trivial, but it is achievable. And once they get the jitter control good enough, they stop trying to make it better because that would just be a needless expense. In extreme cases, they’ve taken astronomical telescopes mounted on airplanes, subject not only to the vibrations of the turbines but also being buffeted by near-sonic wind speeds, and made the jitter small enough that you could get more-or-less diffraction-limited pictures at most wavelengths of interest<ref name="SOFIA Observer's Handbook">[https://www.sofia.usra.edu/science/proposing-and-observing/sofia-observers-handbook-cycle-4/7-instruments-iv-forcast/71-2 SOFIA Observer's Handbook for Cycle 4, 7.1.2 Camera Performance]</ref><ref name="simulating SOFIA">[https://www.researchgate.net/publication/319495615_Simulating_SOFIA's_image_jitter_performance_and_how_the_results_compare_to_in-flight_measurements Simulating SOFIA's image jitter performance and how the results compare to in-flight measurements]</ref>. So diffraction-limited operation of visible and near-visible colored lasers even in noisy and vibration prone environments looks to be achievable.		If your diffraction-limited spot size is 1 cm across, no one will care if the point of aim is jumping around by 3 mm or so. This is not trivial, but it is achievable. And once they get the jitter control good enough, they stop trying to make it better because that would just be a needless expense. In extreme cases, they’ve taken astronomical telescopes mounted on airplanes, subject not only to the vibrations of the turbines but also being buffeted by near-sonic wind speeds, and made the jitter small enough that you could get more-or-less diffraction-limited pictures at most wavelengths of interest<ref name="SOFIA Observer's Handbook">[https://www.sofia.usra.edu/science/proposing-and-observing/sofia-observers-handbook-cycle-4/7-instruments-iv-forcast/71-2 SOFIA Observer's Handbook for Cycle 4, 7.1.2 Camera Performance]</ref><ref name="simulating SOFIA">[https://www.researchgate.net/publication/319495615_Simulating_SOFIA's_image_jitter_performance_and_how_the_results_compare_to_in-flight_measurements Simulating SOFIA's image jitter performance and how the results compare to in-flight measurements]</ref>. So diffraction-limited operation of visible and near-visible colored lasers even in noisy and vibration prone environments looks to be achievable.

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	Reference		Reference
	<ref~~>[https://apps.dtic.mil/sti/citations/~~ADA464385 ~~J. Negro and S. Griffin,~~ "~~Inertially Stabilized Platforms for Precision Pointing: Applications to directed-energy weapons and space-based lasers", US Government report ADA464385, Aug 17 2006]~~</ref>		<ref name="ADA464385"></ref>
	mentions that directed energy weapon systems must have sub-microradian (less than 10<sup>-6</sup>) accuracies, and that (as of the time of the report in 2006) existing technology provides such capabilities – although it then goes on to describe many of the engineering challenges involved. It mentions that the gas and fluid flow of the laser mechanism (typically for cooling, but possibly also involved in beam generation) makes laser jitter control more challenging than for telescopes which lack such flows. In addition, directed energy weapons often must turn significantly faster than telescopes, resulting in larger disturbances and increased issues with jitter.		mentions that directed energy weapon systems must have sub-microradian (less than 10<sup>-6</sup>) accuracies, and that (as of the time of the report in 2006) existing technology provides such capabilities – although it then goes on to describe many of the engineering challenges involved. It mentions that the gas and fluid flow of the laser mechanism (typically for cooling, but possibly also involved in beam generation) makes laser jitter control more challenging than for telescopes which lack such flows. In addition, directed energy weapons often must turn significantly faster than telescopes, resulting in larger disturbances and increased issues with jitter.

Lwcamp: /* How much jitter? */

2025-03-23T17:52:54Z

How much jitter?

← Older revision		Revision as of 10:52, 23 March 2025
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	Reference		Reference
	<ref>[https://apps.dtic.mil/sti/citations/ADA464385 J. Negro and S. Griffin, "Inertially Stabilized Platforms for Precision Pointing: Applications to directed-energy weapons and space-based lasers", US Government report ADA464385, Aug 17 2006]</ref>		<ref>[https://apps.dtic.mil/sti/citations/ADA464385 J. Negro and S. Griffin, "Inertially Stabilized Platforms for Precision Pointing: Applications to directed-energy weapons and space-based lasers", US Government report ADA464385, Aug 17 2006]</ref>
	mentions that directed energy weapon systems must have sub-microradian (less than 10<sup>-6</sup>) accuracies, and that (as of the time of the report in 2006) existing technology provides such capabilities – although it then goes on to describe many of the engineering challenges involved). It mentions that the gas and fluid flow of the laser mechanism (typically for cooling, but possibly also involved in beam generation) makes laser jitter control more challenging than for telescopes which lack such flows. In addition, directed energy weapons often must turn significantly faster than telescopes, resulting in larger disturbances and increased issues with jitter.		mentions that directed energy weapon systems must have sub-microradian (less than 10<sup>-6</sup>) accuracies, and that (as of the time of the report in 2006) existing technology provides such capabilities – although it then goes on to describe many of the engineering challenges involved. It mentions that the gas and fluid flow of the laser mechanism (typically for cooling, but possibly also involved in beam generation) makes laser jitter control more challenging than for telescopes which lack such flows. In addition, directed energy weapons often must turn significantly faster than telescopes, resulting in larger disturbances and increased issues with jitter.

	Jitter is reduced by making your pointing structure compact and stiff. Long extended objects (anything that looks like a gun barrel, for example) tend to be more wibbly and will increase the beam jitter.		Jitter is reduced by making your pointing structure compact and stiff. Long extended objects (anything that looks like a gun barrel, for example) tend to be more wibbly and will increase the beam jitter.

Lwcamp: /* How much jitter? */

2025-03-23T17:52:17Z

How much jitter?

← Older revision		Revision as of 10:52, 23 March 2025
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	In addition, thermal cycling (going from sunlight into the Earth's shadow, or vice versa) will cause significant additional jitter for the Hubble Space Telescope<ref name="Bely_May"></ref>.		In addition, thermal cycling (going from sunlight into the Earth's shadow, or vice versa) will cause significant additional jitter for the Hubble Space Telescope<ref name="Bely_May"></ref>.

	It is worth noting that reference <ref name="Bely_May"></ref> notes that with modern technology, the Hubble Space Telescope jitter could be even further reduced by the use of active optics. It is claimed that these active optics would also significantly help with the increased jitter of turning and thermal cycling.		It is worth noting that reference <ref name="Bely_May"></ref> notes that with modern (as of 1992) technology, the Hubble Space Telescope jitter could be even further reduced by the use of active optics. It is claimed that these active optics would also significantly help with the increased jitter of turning and thermal cycling.

	Reference		Reference

Lwcamp: /* How much jitter? */

2025-03-23T17:50:07Z

How much jitter?

← Older revision		Revision as of 10:50, 23 March 2025
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	Reference		Reference
	<ref>[https://apps.dtic.mil/sti/citations/ADA464385 J. Negro and S. Griffin, "Inertially Stabilized Platforms for Precision Pointing: Applications to directed-energy weapons and space-based lasers", US Government report ADA464385, Aug 17 2006]</ref>		<ref>[https://apps.dtic.mil/sti/citations/ADA464385 J. Negro and S. Griffin, "Inertially Stabilized Platforms for Precision Pointing: Applications to directed-energy weapons and space-based lasers", US Government report ADA464385, Aug 17 2006]</ref>
	mentions that directed energy weapon systems must have sub-microradian (less than 10<sup>-6</sup>) accuracies, and that (as of the time of the report in 2006) ~~stable-platform gyros provide~~ such capabilities – although it then goes on to describe many of the engineering challenges involved). It mentions that the gas and fluid flow of the laser mechanism (typically for cooling, but possibly also involved in beam generation) makes laser jitter control more challenging than for telescopes which lack such flows. In addition, directed energy weapons often must turn significantly faster than telescopes, resulting in larger disturbances and increased issues with jitter.		mentions that directed energy weapon systems must have sub-microradian (less than 10<sup>-6</sup>) accuracies, and that (as of the time of the report in 2006) existing technology provides such capabilities – although it then goes on to describe many of the engineering challenges involved). It mentions that the gas and fluid flow of the laser mechanism (typically for cooling, but possibly also involved in beam generation) makes laser jitter control more challenging than for telescopes which lack such flows. In addition, directed energy weapons often must turn significantly faster than telescopes, resulting in larger disturbances and increased issues with jitter.

	Jitter is reduced by making your pointing structure compact and stiff. Long extended objects (anything that looks like a gun barrel, for example) tend to be more wibbly and will increase the beam jitter.		Jitter is reduced by making your pointing structure compact and stiff. Long extended objects (anything that looks like a gun barrel, for example) tend to be more wibbly and will increase the beam jitter.

Lwcamp: /* How much jitter? */

2025-03-23T17:44:38Z

How much jitter?

← Older revision		Revision as of 10:44, 23 March 2025
Line 41:		Line 41:
	Reference		Reference
	<ref>[https://apps.dtic.mil/sti/citations/ADA464385 J. Negro and S. Griffin, "Inertially Stabilized Platforms for Precision Pointing: Applications to directed-energy weapons and space-based lasers", US Government report ADA464385, Aug 17 2006]</ref>		<ref>[https://apps.dtic.mil/sti/citations/ADA464385 J. Negro and S. Griffin, "Inertially Stabilized Platforms for Precision Pointing: Applications to directed-energy weapons and space-based lasers", US Government report ADA464385, Aug 17 2006]</ref>
	mentions that directed energy weapon systems must have sub-microradian (less than 10<sup>-6</sup>) accuracies, and that (as of the time of the report in 2006) stable-platform gyros provide such capabilities – although it then goes on to describe many of the engineering challenges involved). It mentions that the gas and fluid flow of the laser mechanism (typically for cooling, but possibly also involved in beam generation) makes laser jitter control more challenging than for telescopes which lack such flows.		mentions that directed energy weapon systems must have sub-microradian (less than 10<sup>-6</sup>) accuracies, and that (as of the time of the report in 2006) stable-platform gyros provide such capabilities – although it then goes on to describe many of the engineering challenges involved). It mentions that the gas and fluid flow of the laser mechanism (typically for cooling, but possibly also involved in beam generation) makes laser jitter control more challenging than for telescopes which lack such flows. In addition, directed energy weapons often must turn significantly faster than telescopes, resulting in larger disturbances and increased issues with jitter.

	Jitter is reduced by making your pointing structure compact and stiff. Long extended objects (anything that looks like a gun barrel, for example) tend to be more wibbly and will increase the beam jitter.		Jitter is reduced by making your pointing structure compact and stiff. Long extended objects (anything that looks like a gun barrel, for example) tend to be more wibbly and will increase the beam jitter.