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Optomechanical accelometry for inertial navigation
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Joe Gwinn
Sep 17, 2021, 7:07:09 PM9/17/21
to
I recently attended a lecture on Optomechanical accelometry for
inertial navigation, from NIST (National Institute for Science and
Technology in the US).
It's very clever, probably an advance in the art. They are at the
noise floor for such devices. One fundamental limitation they
mentioned was "laser noise" causing a 1/f noise peak at low
frequencies. This rang a bell - didn't Phil Hobbs invent a way to
cancel laser relative intensity noise (RIN)?
Yes. And it seems to be a perfect place to use this method, so I told
the speakers of US patent 5,134,276 and the companion article in the
literature. They had heard of Phil and have his book on electro
optics. It would be dead simple to cancel RIN in their application,
so I bet they will do it.
The application:
.<https://www.nist.gov/people/feng-zhou>
Look at the first two papers listed under "Publications", "Broadband
thermo mechanically limited sensing with an Optomechanical
accelerometer" and "Electrooptic frequency combs for rapid
interrogation in cavity optomechanics".
More papers are likely to emerge.
Joe Gwinn
inertial navigation, from NIST (National Institute for Science and
Technology in the US).
It's very clever, probably an advance in the art. They are at the
noise floor for such devices. One fundamental limitation they
mentioned was "laser noise" causing a 1/f noise peak at low
frequencies. This rang a bell - didn't Phil Hobbs invent a way to
cancel laser relative intensity noise (RIN)?
Yes. And it seems to be a perfect place to use this method, so I told
the speakers of US patent 5,134,276 and the companion article in the
literature. They had heard of Phil and have his book on electro
optics. It would be dead simple to cancel RIN in their application,
so I bet they will do it.
The application:
.<https://www.nist.gov/people/feng-zhou>
Look at the first two papers listed under "Publications", "Broadband
thermo mechanically limited sensing with an Optomechanical
accelerometer" and "Electrooptic frequency combs for rapid
interrogation in cavity optomechanics".
More papers are likely to emerge.
Joe Gwinn
DecadentLinux...@decadence.org
Sep 17, 2021, 7:45:32 PM9/17/21
to
Joe Gwinn <joeg...@comcast.net> wrote in
news:r86akg5d0o1mi0pgj...@4ax.com:
The IRU (Inertial Reference Unit) we used was housed in an 8 inch
cube made by GE. It was $50k. We sold it for $100k. They are some
of the most accurate devices of the type known.
<https://www.google.com/url?sa=i&url=http%3A%2F%2Fwww.mce-asic.co.uk%
2Fmilitary%2Fsystems%2Favionics%2Fdocs%2FIRU-land-
navigation.pdf&psig=AOvVaw0LADLrwmBNYV_0fmJcaU4q&ust=1632008640585000
&source=images&cd=vfe&ved=0CAkQjRxqFwoTCPi2vIyYh_MCFQAAAAAdAAAAABAD>
news:r86akg5d0o1mi0pgj...@4ax.com:
cube made by GE. It was $50k. We sold it for $100k. They are some
of the most accurate devices of the type known.
<https://www.google.com/url?sa=i&url=http%3A%2F%2Fwww.mce-asic.co.uk%
2Fmilitary%2Fsystems%2Favionics%2Fdocs%2FIRU-land-
navigation.pdf&psig=AOvVaw0LADLrwmBNYV_0fmJcaU4q&ust=1632008640585000
&source=images&cd=vfe&ved=0CAkQjRxqFwoTCPi2vIyYh_MCFQAAAAAdAAAAABAD>
Phil Hobbs
Sep 17, 2021, 7:48:31 PM9/17/21
to
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510
http://electrooptical.net
http://hobbs-eo.com
Joe Gwinn
Sep 19, 2021, 2:42:34 PM9/19/21
to
Interesting. How does it compare with the FOG-based IMUs from iXblue?
I'm guessing that canceling the RIN noise will reduce the bias error,
which typically dominates errors important in dead-reckoning
navigation.
Joe Gwinn
DecadentLinux...@decadence.org
Sep 19, 2021, 9:54:38 PM9/19/21
to
Joe Gwinn <joeg...@comcast.net> wrote in
news:mo0fkg1ept3d0au1a...@4ax.com:
think)they were very long fiber optic coils in three axis, IIRC.
I seem to remember seeing something in one of the of hard copy tech
publications I used to read, like NASA Tech Briefs or such. That was
a long time ago. I am sure they have come a long way since on
accuracy improvement, etc. You know... all the stuff that counts in
such an instrument.
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