In desperate need of some income to supplement her husbands low salaries, Norwood sold blouses in a New Haven department store. This job was something she wouldn't have gotten if she had disclosed her MIT degree. Norwood was steadfast throughout her extensive training on how to read a salestax chart. She also challenged herself by taking advanced math classes at Yale. She sold frilly blouses, but she preferred tailored clothes until she was hired to teach business math at the Junior College of Commerce in New Haven.Although teaching math was a good step, Norwood's real career began when a friend invited her to visit New Jersey's US Army Signal Corps Laboratories. They jumped at the opportunity to work at Evans Signal Lab together in 1948.Follow the windNorwood was assigned to the labs meteor radar group at the same time radar was being used in meteorology. He was asked to create a radar reflector to weather balloons to allow them to track high-altitude winds.You can sit down and think about a problem and then the solutions will come to you. The device was suspended from fishing swivels and would spin in wind to produce a distinctive pulsating signal that radar could track. Meteorologists were able to accurately determine wind velocity above 100,000 feet, which is the height at that weather balloons burst. This feat enabled long-term weather prediction to be possible for the first. Norwood, at the age of 22, developed the device. It was later patentable.Norwood at Storm Detector Radar Set, US Army Signal Corps Labs. Drawings of her patented radar reflector to weather balloons. NASA's Surveyor (right photograph) sent the image of a moonrock back to Earth in 1966 via Norwoods transmitter. NASAJPL; COURTESY of VIRGINIA, NORWOOD; NASA/JPL(SURVEYOR); NOWOOD VIA GOOGLE PENTS (DIAGRAMS).Lab members began discussing the design of telemetry towers to be used in a missile range at Cape Canaveral, Florida. One of the lab members said, "Oh, let's make them 1,000 feet tall." She recalls being amazed at her colleague's proposal to build towers almost as tall. One tower was intended to be constructed several hundred miles off shore, but Norwood realized it would be costly to build and vulnerable to hurricanes.Norwood used historical temperature and wind data to determine the height of the towers. To get the data, several male colleagues went to Washington, DC, but came back empty-handed. Norwood met Frances Whedon herself, the US Signal Corps meteorologist who refused to release her data. Whedon had a 1924 MIT meteorology degree. Norwood says that she was initially brusque with men but took a liking to me and quickly obtained permission to go to the archives where Whedons weather logs were stored.Norwood estimated that towers should be about 100 feet tall. She claims that they were determined to build 1,000-foot towers. I was able to prove through data that they could live with towers shorter than their recommended height. They were used in missile tests in 1950s and 1960s.Learn a tradeNorwood claims that despite having a patent awarded for her first assignment in weather radar, she did more important work once she joined the antenna group. The Signal Corps was interested to explore different types of radar antennas. They were inspired by the microwave radar technology that was developed at MIT's Radiation Lab. The antenna group at Evans was one of the first to develop antennas and transmitters using microwaves at shorter wavelengths. They also figured out how this technology could be used. Norwood was granted a second patent in that same group for his long-range classified-tracking antenna. Its feed did not have to rotate in order to track an incoming signal. Instead, it used polarization for identifying the signals angle and direction. It turned out that being part of an antenna group would be a valuable asset as the field of microwave radio antennas grew. Norwood said, "I learned a trade."She and her husband moved to California in 1953. She quickly found a job at Sylvania Electronic Defense Labs. There she set up an antenna testing range and sourced equipment from Bill Hewlett (SM 36) and Dave Packard. She and her baby girl moved to Los Angeles a year later with her husband. There, she joined Hughes Aircraft's antenna lab. Norwood says she went to work with Lester Van Atta who had done pioneering radar research at MIT Rad Lab in early days of wartime and managed one of the most impressive antenna outfits in America. Some of the most interesting antennas were built by us, some of which I can share with you.Norwood in her Brass Rat carries a slide rule from 1963. COURTESY OF VIRGINIA NOWOODShe designed an antenna to identify friends and foes in one of the now classified projects. To prevent warplanes shooting down their own aircraft, the IFF must pick up a unique signal from all US aircraft. She had to ensure that the IFF antenna would not block another larger antenna behind it, a long-distance surveillance radar scanning the horizon looking for missiles or aircraft. Hughes holds a patent on the folding S-shaped dipole antenna that she invented. She says it worked but she is only half-joking. The friend-or-foe identification system is so important that the development of its components was divided to ensure that no one would have access to it all.How to manage microwaves (and how to manage men)Norwood was appointed to head the microwave group at Hughes' missile laboratory in 1957. Hughes was not pleased to see a woman rise in the ranks. She shed was the first woman to join technical staff. At first, a permit was denied for the lot because only men could park there. However, a colleague told her that women with children should not work in the labs. Norwood was only three days away when her second child, a girl named Alice, was born in 1959. One man quit after he was given the charge of circuitry for missiles and microwave antennas. He asked Norwoods to join him in Hughes's group several years later. She refused.Norwood and Hughes antenna colleagues in 1956; an patented antenna she invented; with Ethelwyn Pecora (the wife of Landsat champion William Pecora), after she won the 1979 Pecora Prize for her contributions to remote sensing. COURTESY OF VIRGINIA NOWOODShe and her team developed antennas for Falcon missiles. Norwood also created the microwave receiver and transmitter for the first communication satellite. Syncom 2, short for Synchronous Communication, was used to make the first satellite call between heads. In 1963, President Kennedy called Prime Minister Abubakar Tafawa Balewa from Nigeria aboard a US vessel in Lagos Harbor. One year later, Syncom3 was used to broadcast to the US the 1964 Tokyo Olympics.Data transfer from the MoonNASA needed a scouting device to report on the suitability for a landing site as it was preparing to send the first man to Mars. Norwood recalls that they didn't want the man to slip down a crack on the moon.Although previous reconnaissance devices had taken images of the approach to the moon, none of them had returned any images upon landing. This rendered them ineffective for studying the surface. Norwood says that there was much debate about what was beneath the moon's top layer. There was a lot of debate about what was below the top layer of moon. Some even believed that the moon was a hollow shell. NASA did not buy into these theories but needed a craft capable of surviving the landing to take photographs on the surface and collect soil samples for analysis.Hughes had already tackled the problem, but Norwood and her microwave team took on the challenge of making Surveyor able to receive commands, send images, and transmit data back to Earth. She says that she was used to having to fit tiny antennas and transmitters between the missile's delicate fins. We were therefore the natural choice to do this job.She was actually the one who designed the transmitter that transmitted all Surveyors data back from Earth. She was also responsible for the design of the system antenna. This planar array, which is much smaller than the usual curved parabolas, folds down compactly for flight, and opens on the moon. The solar panel attached it to the solar panel, which captured the energy needed to power all lunar lander systems.Surveyor was launched on May 31, 1966. Norwood, who had already moved to the space systems division, recalled being at Hughes, looking at screens that showed the command center at Jet Propulsion Lab (JPL), as Surveyor reached the moon on June 2. The JPL team confirmed that Surveyor had successfully landed thanks to Norwood's communications equipment. A huge yell was heard. NASA was able confirm the site was hard enough to allow a manned craft landing when the signals Surveyor transmitted back to Norwoods transmitter were converted into images and data.Get ready to see the Earth from a closer perspectiveNorwood began to think about a project that didn't have anything to do with weapons or space exploration, and that would not involve classified data. She says it was not fun to enter a "black chamber" where your work had to be stored in a safe each time you left the room.NASA and the US Geological Survey had been discussing building a satellite to monitor Earth's resources and observe it. She says that satellites can be used to reach the highest mountain peaks and other places geologists have not yet been able to access. NASA planned to equip the satellite's return beam video (RBV) camerastelevision cameras, similar to the ones used in the lunar missions. Three RBVs were used to capture analog freeze frames of Earth with different filters. These filters would record the near-infrared, green, and red sections of electromagnetic spectrum.Norwood believed that a multispectral scan (MSS), could prove more beneficial. This scanner could capture both visible light and invisible light, and then sort it into multiple spectral bands. It would create a treasure trove full of information. One band could allow for the study of water quality, another could reveal the vigor and yield of crops, while a third could show the absorption of chlorophyll; others could be used in order to determine the soil moisture or density of snowpack.Agronomists have been flying spectrometers in planes to gather data from a sample of fields. A satellite scanner could gather images continuously, allowing agronomists to monitor exactly how many acres are being grown of each crop, anywhere in the world. Tree arborists can spot signs of disease or blight early and act before they spread. Managers of dams and watersheds will receive regular data feeds on soil moisture, flooding and other pertinent information. Managers of census could monitor how fast wild and agricultural land become urbanized. Economists could also gauge the relative economic success of different neighborhoods by comparing their green spaces.The scanner would also be digital. The scanner's detectors would record individual pixels. Each pixel represents an area approximately the same size as a football field. These pixels could be strung together to create lines of data, which could be combined to make images line-by-line. Computers could analyze digital images. Data from different spectral bands could then be compared, providing far greater precision than the visual analysis of analog images. The ability to analyze spectral data allowed for identification of the material being imaged. Fields of wheat and corn, for example, would appear identical from space but can be distinguished by unique spectral signatures. There are many possible uses for a multispectral scanner.Norwood and James Hodgson, Labor Secretary, discuss Landsats multispectral scanning at a 1972 conference. COURTESY OF VIRGINIA NOWOODNorwood presented her idea to Hughes' top brass and was awarded $100,000 to create a prototype for NASA.To find out the data needed by potential users, she met with them and narrowed down the six most important spectral bands. She then set about creating a system to efficiently image these bands and transmit the data back from Earth.NASA had calculated that the satellite would orbit the poles at 500 nautical miles high. The satellite would travel from north to south as the planet rotates beneath it. Norwoods scanner would record the light reflecting off a 100-nautical mile wide diagonal strip of Earth. Each orbit would show Earth rotating, and a new strip of 100-nautical miles would be prepared for scanning. The entire planet could then be scanned in 18 days. Because the scanner is always in the same position relative to the sun at every latitude, the lighting will be consistent when the strips are assembled.Norwood knew from the beginning that the scanner wouldn't withstand the strain of constantly moving back and forth in order to capture the width. She came up with the idea of using a mirror to reflect light onto it that could pivot back and forth. The incoming light would then be divided into six spectral bands and directed to the detectors for each one. The scanner must capture six lines per second to keep up with orbit speed. Each spectral band requires six sensors. The sensor data would then be digitalized and sent to ground stations, where it could either be decoded into images or combined to create composite images.Norwood insisted that the data stream be digital. NASA was skeptical that the six-bit MSS data would produce high-quality images. She knew that it would be difficult to process an analog signal continuously accurately. Digital would allow you to calibrate each sensor's photon levels very precisely. She says that accuracy is important because otherwise, the data can be reconstructed into images in a messy manner. She worked with Hughes microwave colleagues to find the best way to digitize sensor data. The data from the MSS would be transmitted to US ground stations as the MSS images the US. Images of the rest of world would then be saved on videotape and sent down to US stations. (Later ground stations would be set up around the globe.NASA officials later told her that the MSS data would be NASA's first digitally transmitted data from space. It would also set the standard for future remote sensing.Norwood consulted Web Howe, an inventor at Hughes, to create the pivoting mirror setup. Howe came up with an innovative design that took advantage of the low gravity space. The pivoting mirror would rock back-and-forth as its edges hit bumpers on each side. It would be lightweight and free from any external forces. There would be no resistance to the mirror moving between bumpers at a constant rate of 13 times per second. The sensors would record six additional lines of data from the reflected sunlight for each spectral band as the mirror moved in one direction, keeping up with the satellite's progress south. Each time it rocked back, the mirror captured the light from the calibration lamp.Norwood was able to see the genius of Howes' design. However, she had to convince many naysayers that it would actually work. She says that Hughes people were primarily electronic people. They shuddered at this idea of a mechanical mirror.Hughes was skeptical at times, but NASA and US Geological Survey researchers were certain that the MSS could not possibly produce useful data. All of them were familiar with the vidicon TV cameras that were used on Surveyor and the early Apollo missions. They also knew how to capture full-frame analog images. They were hesitant about the idea of launching a new mechanical device that scans line by line and relied on a banging mirrored, of all things. For more than a decade, the debate about which system should win raged. Mapmakers such as myself were skeptical of the multispectral scanner. We couldn't believe it would have geometric integrity. Alden Colvocoresses, USGS cartographer, later admitted that they were wrong.Only a few people were skeptical of the idea. Norwood states that they knew there was a banging reflection. They felt it was too crude.NASA requested that the scanner's dimensions, weight and power requirements be reduced. Norwood and her team reduced the design of the scanner from having six bands to four. The prototype measured 89x59x40 cms and had a 9x13-inch oval mirror made of beryllium to withstand banging and not warp or vibrate. It also included the controversial bumpers that caused engineers to cringe. It weighed 48 kilograms or approximately 105 pounds.Norwood instructed researchers to load a breadboard version the scanner onto a truck. She says it was just a few boxes. It was possible to use any weight you wanted. Norwood was not surprised at the high quality test images after having spent so much time working out the specifications.This false-color image was captured by a test version of Norwoods multispectral scanning scanner from a truck two years before Landsat 1s launch. NASA - COURTESYNASA resolved the RBV-versus MSS debate by including both satellites. The prototype was used as it was, since Norwood's prototype wasn't ready to be made into a finished product. Naomi Norwood, her daughter, said that nobody expected the prototype to work, except my mother and other workers. The scanner was still considered experimental. Norwood said that the average person did not realize how distorted a TV camera can produce. We needed scientific precision.It's a stunning debutNorwood was seated with her husband and son at Vandenberg Air Force Base in California on July 23, 1972 as the Earth Resources Technology Satellite (later renamed Landsat 1) was launched. She had her MSS prototype aboard. She said that she had never witnessed a rocket launch in person. That was quite exciting.Researchers gathered at NASA's Goddard Space Flight Center two days later to view the first MSS data converted into images. A technician complained about the horrible moir pattern when images of clouds turned into images of land. They soon realized the image was actually of the Ouachita Mountains of Oklahoma. The wavy lines were accurate representations of the folds. One geologist was overcome with emotion. Another MSS skeptic, however, said that I was wrong. I won't eat crow. It's not big enough. I'm going to eat raven.One of the two satellite videotape recorders that stored RBV images and MSS data was destroyed by a powerful surge of power eleven days after launch. This occurred while the satellite was not accessible from the ground stations in the USA. A second surge of power caused by the RBVs rocked satellite three days later. This caused it to point away form Earth and threatened the mission. After the RBVs had been turned off, the satellite was able to correct itself and engineers decided to discontinue them for good. The stunningly sharp and clear images that Norwoods MSS was sending back from Earthdigitally were breathtaking.She says that she used to go to meetings where people would jump up and down when they discovered another way to use the data. Not just scientists, but anyone could buy a Landsat photo of any location on Earth for $1.25 for years. Over the years, prices and access to images have changed. However, in 2009 all Landsat images were made free of charge.Image from Landsats of Mount St. Helens following its eruption in 1980. Norwood (94) keeps a daily count of bird species. MICHELLE GROSKOPF; USGS/NASA LANDSATNorwood was part of the four subsequent versions of Landsat that were launched in 1978, 1982 and 1984. Landsats 4/5 flew versions of Norwood's four-band MSS, as well as her original design. Thematic mapper (also known as the thematicmapper) scanned six of shed's original spectral bands, plus another. She moved to Hughes' electro-optics system group in 1977, and was a senior scientist, then a laboratory engineer. There she worked on large active antennas for space, as well as other classified government projects.Norwood started collecting and restoring antique clocks after she retired in 1989. She often made the parts herself. She still has a passion for sports cars, even though her license was revoked due to the pandemic. Norwood says that her six-speed Mazda Miata, which is silvery-blue, handles better than any of her other Jaguars, MGs and Alfas. She also enjoys birdwatching, sending her daughter every morning a list of the species she sees in her yard (she used to count 18).Since 1972, the Landsat scanning software that she created has kept an eye on the globe. Over the years, the scanners have evolved and Landsat 8 launched in 2013. It features the original push-broom shed design. The detectors are placed across the image area, sampling every line as it moves in its orbit. There is no need for a mirror. She says that this design would have been my first choice. Actually, I designed one. We didn't have the detectors that can take thousands of detectors without gaps. Landsat 9 will launch in September 2021.In 1972, no one could have predicted the Landsats' impact. It played a crucial role in introducing digital imaging. The scanners documented the disappearance of the Aral Sea between Kazakhstan, Uzbekistan. This lake was the fourth largest in the world before two of its feeder river were diverted to agricultural purposes. The Landsats images from the 1988 Yellowstone Park fires have greatly aided our understanding of fire science. It also captured such important events as the retreating glaciers, the incredible growth of Beijing and the eruptions of Mount St. Helens, 1980.Norwood was honored by the American Society for Photogrammetry and Remote Sensing with a lifetime achievement award. Her favorite Landsat image is more important to her. She says that she likes the one with my house. It was captured by the original Landsat during one of its first flights over LA in 1972. She now has it hanging in a hallway in her house. It shows a clear image of LA, a small patch of the Pacific and her modest house that is hidden in the Santa Monica Mountains.
