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US Navy’s new unhackable GPS alternative.
https://www.popularmechanics.com/mil...al-navigation/
The Navy’s Automated Celestial Navigation System would replace manual shipboard measurements with something more accurate, while Special Operations Command experts are developing a handheld device for commandos. Both pieces of tech are aiming for GPS-level precision. “The best accuracy for celestial navigation with certainty is within a couple of meters,” says Benjamin Lane of the Advanced Position, Navigation & Timing Instrumentation unit at Draper Laboratory in Cambridge, Massachusetts. “In practice, we are within a factor of a few of that.” SPOOFING, HACKING, OR DESTROYING THE STARS? NOT HAPPENING. The new systems use infrared rather than visible light for locating stars, allowing daytime navigation. The stars shine just as brightly in the day sky as they do at night, but their light is masked by sunlight scattered by the atmosphere. The scattering is strongest at short wavelengths. If you’ve ever glimpsed the sky, you know that blue light is scattered the most. But glimpse that same sky with a filter that allows only infrared light, and the sky suddenly becomes dark—and filled with stars. “Twenty years ago, these infrared sensors were quite expensive,” says George Kaplan, a consultant for the U.S. Naval Observatory. “Since then, costs have been going down and the pixel count is getting higher.” The rise of celestial navigation is also helped along with another piece of tech called a “phased optical array,” which does not need to be pointed at a section of the sky like a telescope does. This type of sensor does not have a lens to focus, but instead has an array of tiny meta-material antennas to capture light. A processing unit can phase-shift the signal from each antenna to achieve the same effect as a movable, focusing lens. |
Every thing old is new again, SR-71 used a star tracker as its prime means of navigation.
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Originally Posted by megan
(Post 11038876)
Every thing old is new again, SR-71 used a star tracker as its prime means of navigation.
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And with several civil alternatives, the Pentagon's GPS decommissioning is in the future
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Originally Posted by flighthappens
(Post 11038879)
Depending on who you believe, 3 blokes did that a little over 2000 years ago!
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How BIG is the device?
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This is what the SR-71 had.
https://timeandnavigation.si.edu/mul...igation-system 90 Meters precision at Mach 3+ is not that bad. This device is said to have inspired the "character" R2D2 from Star Wars. |
Defeated by cloud though, que the enemy developing weather control.
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Clouds at FL850?
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Originally Posted by Less Hair
(Post 11039175)
Clouds at FL850?
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Clouds at FL850? |
Originally Posted by Less Hair
(Post 11039008)
This is what the SR-71 had.
https://timeandnavigation.si.edu/mul...igation-system 90 Meters precision at Mach 3+ is not that bad. This device is said to have inspired the "character" R2D2 from Star Wars. Thanks - needs a bit of work to fit on my wrist I think........... but then the original GPS units wouldn't fit on my kitchen table |
It is using stars. Celestial navigation. Data fed into the aircraft nav system. The SR-71 was meant to be used for Post-SIOP reconnaissance when no working satellite or nav-emitter would exist anymore.
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US Army I think still use the DAGR which has anti-spoofing technology, they did a while back anyhow when I worked for them, although have not ever heard of a case of spoofing a GPS in theatre - nobody I spoke to about it seemed too worried, and many folk carried/wore a consumer Foretrex 401, which seemed to do the job at least as well (using MGRS setting, civilian satellites, and for 1/10th of the price).
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Royal Navy still teaches the use of a sextant. The US Navy has only in recent years re-introduced teaching it.
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Be nice to get a system that alos doesn't lose accuracy in the event of a major solar storm heating the ionosphere and changing the signal path for the GPS signals.
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Originally Posted by flash8
(Post 11039347)
US Army I think still use the DAGR which has anti-spoofing technology, they did a while back anyhow when I worked for them, although have not ever heard of a case of spoofing a GPS in theatre - nobody I spoke to about it seemed too worried, and many folk carried/wore a consumer Foretrex 401, which seemed to do the job at least as well (using MGRS setting, civilian satellites, and for 1/10th of the price).
https://www.voanews.com/silicon-vall...gps-disruption https://www.defensenews.com/global/e...ng-nato-drill/ |
Salute!
Do not diss those folks at Draper and other places that developed and fielded nav gear that used the stars to help their inertial systems. I worked with the Draper folks and the USN to develop ways to check on the guidance systems of the Trident missiles. Parts were hard to get because many vendors had gone outta business. Meanwhile, the subs were cruising about with all those missiles and the USN wanted to make sure their guidance systems still worked as advertised. Our company was hired to help with a test program that verified the specified accuracy of the missile's guidance system. . During the Reagan years, many documents about the Trident missile were put on the street. Was like us "catch us if you can" challenge. The basics were well known, but nobody else could come close to making such a system work. Lemme put this into perspective...... the sub could launch a missile from 3,000 or 4,000 miles away and it would hit inside a futbol field. The thing that amazed me was the guidance unit had an optical component that was programmed to look for a star during mid-flight and correct the inertial system. A series of holes in the gimbal housings would line up and find the star and then correct the inertial and then.... Remember, these folks were the ones that developed and fielded the Apollo guidance units, and we know what they did. I like the idea of using stars versus satellites. A bad guy could seriously wreck havok on the sats, but how could they move the stars? I have always wondered about depending too much on the sats. And I helped with the original JDAM mission planning efforts. Gums sends... |
The U.K. has been working on a “quantum compass” (far more accurate INAS) for years.
First example is large and only suitable for boats (new Trident subs?). But compare the size of the very first INAS unit (USS Nautilus) and recent commercial INAS units..... https://www.imperial.ac.uk/news/1889...ation-without/ https://www.zdnet.com/article/gps-ki...ee-navigation/ https://cimg8.ibsrv.net/gimg/pprune....795a05282.jpeg https://insideunmannedsystems.com/wo...now-available/ https://cimg2.ibsrv.net/gimg/pprune....cc2bfc02c.jpeg |
Originally Posted by Less Hair
(Post 11039175)
Clouds at FL850?
https://weather.com/science/weather-...ates-june-2019 |
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