Virginia Norwood, 'Mother' of Satellite Imaging Systems, Dies At 96 (nytimes.com) 27
Virginia Norwood, an aerospace pioneer who invented the scanner that has been used to map and study the earth from space for more than 50 years, has died at her home in Topanga, Calif. She was 96. The New York Times reports: Her death was announced by the United States Geological Survey, whose Landsat satellite program relies on her invention. Her daughter, Naomi Norwood, said her mother was found dead in her bed on the morning of March 27. The Landsat satellites, speeding 438 miles above the surface, orbit the earth every 99 minutes and have captured a complete image of the planet every 16 days since 1972. These images have provided powerful visual evidence of climate change, deforestation and other shifts affecting the planet's well-being.
Ms. Norwood, a physicist, was the person primarily responsible for designing and championing the scanner that made the program possible. NASA has called her "the mother of Landsat." At the dawn of the era of space exploration in the 1950s and '60s, she was working at Hughes Aircraft Company developing instruments. One of a small group of women in a male-dominated industry, she stood out more for her acumen. "She said, 'I was kind of known as the person who could solve impossible problems,'" Naomi Norwood told NASA for a video on its website. "So people would bring things to her, even pieces of other projects." [...]
Over the next 50 years, new Landsat satellites replaced earlier ones. Ms. Norwood oversaw the development of Landsat 2, 3, 4 and 5. Currently, Landsat 8 and 9 are orbiting the earth, and NASA plans to launch Landsat 10 in 2030. Each generation satellite has added more imaging capabilities, but always based on Ms. Norwood's original concept. The Landsat program has mapped changes in the planet brought on by climate change and by human actions. They include the near disappearance of the Aral Sea between Kazakhstan and Uzbekistan, the shrinking of the Great Salt Lake in Utah, the evolving shape of the Mississippi Delta, and the deforestation and increasing agricultural use of land in Turkey and Brazil.
Ms. Norwood, a physicist, was the person primarily responsible for designing and championing the scanner that made the program possible. NASA has called her "the mother of Landsat." At the dawn of the era of space exploration in the 1950s and '60s, she was working at Hughes Aircraft Company developing instruments. One of a small group of women in a male-dominated industry, she stood out more for her acumen. "She said, 'I was kind of known as the person who could solve impossible problems,'" Naomi Norwood told NASA for a video on its website. "So people would bring things to her, even pieces of other projects." [...]
Over the next 50 years, new Landsat satellites replaced earlier ones. Ms. Norwood oversaw the development of Landsat 2, 3, 4 and 5. Currently, Landsat 8 and 9 are orbiting the earth, and NASA plans to launch Landsat 10 in 2030. Each generation satellite has added more imaging capabilities, but always based on Ms. Norwood's original concept. The Landsat program has mapped changes in the planet brought on by climate change and by human actions. They include the near disappearance of the Aral Sea between Kazakhstan and Uzbekistan, the shrinking of the Great Salt Lake in Utah, the evolving shape of the Mississippi Delta, and the deforestation and increasing agricultural use of land in Turkey and Brazil.
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imagen (Score:1)
The line between genius and madness (Score:3)
When I was in college, many moons ago, I was doing some machine vision stuff and I came across an early tool called the Haralick Matrix for classifying satellite images into land use types. From Landsat images, if memory serves.
Later on I came across his face on the History channel ... talking about bible codes.
https://en.m.wikipedia.org/wik... [wikipedia.org]
Genius and madness...
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When I was in college, many moons ago, I was doing some machine vision stuff and I came across an early tool called the Haralick Matrix for classifying satellite images into land use types. From Landsat images, if memory serves.
Later on I came across his face on the History channel ... talking about bible codes.
https://en.m.wikipedia.org/wik... [wikipedia.org]
Genius and madness...
I am both an Mechanical Engineer and Historian. It has been my observation that most all Geniuses pay for that Genius in some way. It can be a quirk, it can be a full blown madness, but it happens. Top rated mathematical people were all known (at least they used to) to enjoy cheesy porn books to the point where they would pass the books amongst themselves until the covers literally fell off. John Nash, the brilliant mathematician, was a a schizophrenic.Some brilliant authors have went off the deep end. It i
Re: The line between genius and madness (Score:2)
Hehe...cheesy math porn...bonus points for passing off infinity over capital xi as a topless woman in a skirt.
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Hehe...cheesy math porn...bonus points for passing off infinity over capital xi as a topless woman in a skirt.
What is really fascinating and has never been truly documented is that MANY top level fiction writers had pen names and wrote porn books in the 60's and 70's. It was a "dirty little secret" in the industry but it sold books for authors and provided them a nice side income. Anne McCaffrey mentions it in her book "Get Off the Unicorn" as she nearly penned one with the title being the name of the book collection.
In modern terms, (Score:2)
Multispectral Scanner System (Score:5, Informative)
The summary doesn't describe what she invented -- the Multispectral Scanner System. This is a scanner that reads pixels along crosswise lines as satellites move in polar orbits around the Earth. It uses a rotating mirror to direct light to the sensors and can read 3-6 wavelengths for each pixel. This allows complete imaging of the earth at several wavelengths every 16-18 days.
There's a good article about her work at https://www.technologyreview.com/2021/06/29/1025732/the-woman-who-brought-us-the-world/ [technologyreview.com].
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It's very nifty technology because it means you only need one sensor, rather than an array of them like a camera, or a scanner.
The technique has also been adopted for high end negative and slide scanners. One super high end colour sensor and a mirror, scanning one pixel at a time.
She invented THAT MS scanner, not MS scanning. (Score:5, Informative)
The summary doesn't describe what she invented -- the Multispectral Scanner System.
She didn't invent "Multispectral Scanner System", which was prior art and had been in use with aircraft platforms for some time. She invented a (brilliant!) variant of it more suited for use in a satellite.
This is a scanner that reads pixels along crosswise lines as satellites move in polar orbits around the Earth. It uses a rotating mirror to direct light to the sensors ...
Prior art scanners used a rotating mirror (e.g. a flat mirror at a 45 degree angle on the end of a motor shaft). Hers used a rocking mirror, scanning a narrow fan rather than the full circle (which from a spacecraft would be mostly dead time, spreading the scan lines out horribly along the satellite's path). A co-invenor did the rock-by-bouncing-the-mirror-off-bumpers part of the design (also brilliant), which lets the mirror be free-falling during the scan. (I'd have probably tried mountng it on torsion springs, which could conduct spacecraft vibrations. ... and can read 3-6 wavelengths for each pixel.
After the scanning mirror deflects the light into the telescope, if I recall correctly, it is brought to a first focus and apertured (at least along the dimension that will be "spread" by wavelength), to avoid smearing light from pixel to pixel according to wavelength), run through a spectrometer (e.g. bounced off a diffraction grating) to spread it by wavelength, and brought to a (two-dimensional) focus on a row of light sensors (one dimension to focus the wavelengths from across the input beam, the other just to collect light from each pixel along the other spacial-dimension. You get as many bands as you have sensors in the row. (Aircraft scanners might have as many as 14, limited by the number of tracks on then-current high-rate analog data recorders, although usually less.) The boundaries between the sensors along the row control the frequency range of each sensor and cross-row aperture the pixel in the dimension that wasn't wavelength-spread (if that wasn't done in the first aperture). Using a reflective diffraction grating and front-surface mirrors, rather than a transmissive grating or prisims and lenses avoids distortion by wavelength.
This allows complete imaging of the earth at several wavelengths every 16-18 days.
Aircraft could scan the length of the flight path. By putting the satellite in a polar orbit the path became infinite and repeating, and by sizing the scan width as wide as an integer fraction of the distance between passes (choosing the orbit so it crosses the same point on earth only after that number of days) one satellite can cover the planet - except maybe near the poles.
She also designed the optics to make the spacial dimension at the sensors the downrange dimension. That meant she could have several parallel rows of sensors and get several scans on each mirror oscillation, thus scanning more finely along the orbital path than the rate of the oscillation of the mirror.
Contemporary aircraft scanners recorded the signal on analog tape, which was digitized later on the ground. When they were developed the digitzation step was too slow, large (the A-D at the site where I worked was two full racks), and expensive to build and fly one on each scanner aircraft. Better to bring tapes from many to a separate site and play them back at a lower speed if desired. A-to-D once, record on digital tapes, and process those many times using various algorithms at whatever speed the algorithms ran.
The economics changes with spacecraft: Narrow communication bandwidth, enormous launch expense makes investment in equipment more worthwhile. Her design did the A-to-D (which includes crossrange pixelization selection) onboard. This greatly reduced the amount of data that needed to be recorded and downlinked, and also avoided synchronization issues between the scanner and the pixel digitizer.
Very early in my career (startin
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Better to bring [the analog] tapes from many [aircraft scanners) to a separate site and play them back at a lower speed if desired. A-to-D them ...
Or play them back at a substantially higher speed if the A-to-D is up to it. That lets you handle a lot more aircraft on you very co$tly A-to-D and computer, and still have lots of computer time left over for actually crunching the data.
inventor (Score:1)
All of these "inventor" claims by unlikely identity classes that I have researched have turned out to be false. This one probably is, also. Typically such a person makes some contribution. Maybe even gets on a patent. But the thing they allegedly "invented" was primarily done by someone else, or was a team effort. Nowadays due to editing you can't check this stuff on wikipedia, because anything contrary to the narrative or even questioning it will be swiftly removed by rightthink enforcers.
The result i
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All of these "inventor" claims by unlikely identity classes that I have researched have turned out to be false. This one probably is, also.
A similar case is Actress Hedy Lamarr. A brilliant woman, often claimed to be the inventor of spread Spectrum communications. No, she did not.
Lamarr and composer George Antheil came up with a very clever SS scheme, and patented it. It came along too late during WW2 to be implemented, but nonetheless a fine piece of work.
Then a few years ago, she and George were inducted into the Inventors hall of fame.
But the stories are pretty much told from a victim narrative and Really inaccurate. Lamarr is given s
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All of these "inventor" claims by unlikely identity classes that I have researched have turned out to be false. This one probably is, also.
A similar case is Actress Hedy Lamarr. A brilliant woman, often claimed to be the inventor of spread Spectrum communications. No, she did not.
Lamarr and composer George Antheil came up with a very clever SS scheme, and patented it. It came along too late during WW2 to be implemented, but nonetheless a fine piece of work.
Sorry, missed the end to the bolded text and gav us all a visual treat! 8^( Then a few years ago, she and George were inducted into the Inventors hall of fame.
But the stories are pretty much told from a victim narrative and Really inaccurate. Lamarr is given sole credit as the sole inventor of SS, and then there is a claim that the Inventors HOF snubbed her because of her sex.
And that's kind of sad - She deserves a hella lot of credit for what she and Anthiel did. There is zero reason to make stuff up, and apply a victim narrative to it. Making stuff up is counterproductive to the fact that women have the same intellectual capacity as men.
BTW, anyone wondering who Antheil was, his most well known piece of music was the theme song to "The 20th Century" Television show.
Signs of the times (Score:3)
My first thought on this was how much of this is real and how much is historical revisionism. A gross injustice to Ms Norwood and her contributions, but that's how things are reported these days.
Some technical detail would have been nice. I'm familiar with the AVHRR scanning systems on NOAA weather satellites, for example.
...laura