Interviews with 20 recent movers found that, consistent with research on the subject, politics alone did not drive a decision to move. But most we spoke to said it did influence their decision, and for some it topped the must-have list — the movers in our analysis are all registered to vote, and nearly all we spoke to intended to vote on Election Day.

Multispectral images are captured with special cameras that separate wavelengths using filters or with instruments that are sensitive to particular wavelengths. These can include light from frequencies that are invisible to the human eye.

To measure the partisan composition of movers, we relied on nationwide voter registration records provided by the data vendor L2. We used statistical software to match each voter identified by L2 as a mover (based on National Change of Address records) to a 2020 voter registration record in the state that they moved from, allowing us to track movers over time.

All movers we spoke to felt politically comfortable in their new homes. Upon retiring, Robert LaRoche, 60, moved from Las Vegas to Spring Hill, Fla., about an hour north of Tampa to live closer to family. While the majority of his old neighbors in a precinct that voted for Mr. Biden by 41 points “did not align with our values,” he said, that’s not why he moved, nor was it why he chose his new home. He sees it as a bonus that he gets to live in a precinct that voted for Mr. Trump in 2020 by 26 points.

Our analysis is an undercount of partisan migration; it may be missing some movers who haven’t yet filed a new address or registered to vote in their new homes. But it probably accounts for most voters who moved, and it shows how population shifts can have political consequences.

Our estimates, based on a New York Times analysis of detailed public voter registration records of more than 3.5 million Americans who moved since the last presidential election, offer a new and extraordinarily detailed glimpse into one of the ways that we segregate from each other — down to the street level.

Mr. LaRoche’s sentiment is shared by more and more Americans — that life is less contentious when the people around you vote the way you do.

Spectral resolution refers to the number and width of the electromagnetic spectrum portions measured by a sensor. Multispectral remote sensing has a poor spectral resolution. Thus, it makes it harder to discern the Earth’s features as easily as hyperspectral sensors. The reason is that multispectral sensors are captured in small numbers due to the wide bands.

Polarizationpolitics

Mr. Troyer, the Republican, moved to a more Republican neighborhood. Mr. Fisher, the Democrat, moved to a more Democratic one.

Previous research has found that most people don’t intentionally seek out politically homogenous areas, but instead share similar preferences with people who vote as they do, with Democrats favoring cities and Republicans favoring the country, on average. A 2015 study, however, found that people favor properties in neighborhoods that reflect their partisan identity.

Due to the limited number of bands in multispectral remote sensing, data analysis and interpretation are straightforward. It is also easier to understand.

Polarizationof light

They have something else in common, too: They both moved away from Sioux Falls. Mr. Troyer left in the fall of 2021, and Mr. Fisher about a year later.

Multispectral sensors commonly collect data from three to six spectral bands in a single observation. Such features make them cost-effective. They are cheap to buy and maintain as the image captures are not complex.

Ronda Kaysen interviewed several researchers and spoke to 20 recent movers. Ethan Singer analyzed millions of detailed voter registration records.

In all three Northern battlegrounds — Pennsylvania, Wisconsin and Michigan — Democrats made small gains through migration. In Pennsylvania, this year’s key battleground, Democratic gains actually came amid population loss: For both parties, more voters moved out than in. But Republicans lost more.

In 2020, they lived across the street from each other in Sioux Falls, S.D. They are both white men of a similar age. Mr. Fisher, 42, is an auto technician; Mr. Troyer, 39, is a sanitation worker. They are both married. They both have associate degrees.

Mr. Biden won Georgia in 2020, the first time a Democrat won the state since 1992. Among more than 140,000 newcomers, Democrats outnumbered Republicans by more than 9,000. Over the same span, at least 10,000 more Republicans than Democrats moved out of the state — a third of them to Florida.

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We used party registration data to determine movers’ partisanship in the 30 states where voters can register for a specific party, and used a statistical model based on past vote history and demographics to estimate partisanship in the others. It’s also worth noting that all of the movers we analyzed have, by definition, re-registered to vote some time since 2020. This is important because party registration is a much better indication of partisanship and vote intention for voters who have registered more recently.

Mr. Troyer, the Republican, moved to a more Republican neighborhood. Mr. Fisher, the Democrat, moved to a more Democratic one.

Spectral imaging was first introduced in the early 1970s and was mainly for military applications. It was originally referred to as multispectral. Due to the increase of spectral bands and advancements through successive generations of imaging, hyperspectral was introduced.

To estimate the difference between Democratic and Republican movers, we leveraged a widely used statistical technique called matching, which enabled us to pair up otherwise similar Democrats and Republicans. We were able to find nearly 750,000 pairs of voters — one Democrat and one Republican each — who were of the same race and gender, who were similar in age and income, and who moved out of the same state and same type of neighborhood.

The 3.5 million movers in our analysis are a small number compared with the 158 million people who voted in 2020, but they do help explain some recent electoral trends — like Florida’s electoral shift to the right or the gains Democrats have made in Georgia.

And Mr. Troyer now lives in Otsego, northwest of Minneapolis, which Mr. Trump won by 27 points. Mr. Troyer said he chose his neighborhood because it was close to his job and family. While he did not intentionally seek out a conservative community, he feels at ease at home and at work. “Everybody I associate with is Republican,” he said. “Everybody at work, the hardworking kind, we’re all Republican.”

Meanwhile, one of the downfalls of hyperspectral remote sensing is its complexity. It has many bands one has to work with; hence, it may be difficult to reduce redundancies or hard work.

Multispectral remote sensing images have lower informational content hence continued use of the same technology over time. Due to the lack of information richness in this imaging technology, it faces a disability of continual development.

In the process, they unwittingly became a part of a nationwide pattern that could matter in a close presidential election.

Meanwhile, in hyperspectral remote sensing, the bands are much narrower. These numerous narrow bands in hyperspectral sensors provide a continuous spectral measurement across the entire electromagnetic spectrum. Therefore, this makes them more sensitive to subtle variations in reflected energy.

In multispectral data, reflected energy in the spectrum spans a wider range. It makes it difficult to get a lot of detail on an object or surface area captured. It is because the wavelength bands are much broader.

Multispectral remote sensing systems use parallel sensor arrays that detect radiation in a small number of broader wavebands.

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Erin Thompson, 39, felt out of step as the lone Republican voice among her Seattle friends. Even dating was hard. “You want to find someone who has the same fundamental belief system as you,” she said. Absent that, “It’s just a little isolating.” In 2021, in search of warmer weather and a community more closely matching her worldview, she moved to Gilbert, a conservative Phoenix suburb.

Hyperspectral cameras as on the other hand, can detect many different wavelengths separately. They can also see across a wider spectrum than a human can by covering parts of the infrared and ultraviolet regions. Therefore, in this imaging technique, analysts will acquire a 2-dimensional image whereby every pixel in the image contains a continuous spectrum.

In contrast, Naomi Hattaway, 48, said politics “did not register one bit” when she moved for work to Fairburn, Ga., a suburb of Atlanta, from Omaha (after a stop in Florida). An independent who previously registered as a Democrat, she said diversity mattered more to her than party affiliation. She feels more at home as a Black mixed race woman in a city with a large Black population and a diverse local government. “It’s everything,” she said, adding that she is “better off living somewhere I belonged.”

Multispectral imaging follows a Low Earth Orbit and sun-synchronous. The multispectral satellites capture data along 5 to 10 bands of the spectrum. Most often, it also captures all three primary colors and a few blocks in the infrared portion.

Mr. Troyer, the Republican from Sioux Falls, moved closer to his wife’s family in Minnesota. Mr. Fisher, the Democrat, moved to escape the harsh South Dakota winters.

“Am I going to fit? Fittingness is a very important criteria for a place to live,” said James Gimpel, a politics professor at the University of Maryland, and co-author of the study. “Nobody wakes up in the morning and says, ‘Gee, I’m looking forward to having a fight with my neighbors.’”

The different choices that movers made are not easily explained by things like voters’ ages, race, income or if they were leaving a rural or urban area. Even when narrowing our comparisons to demographically similar pairs of people from the same kinds of neighborhoods — people like Mr. Fisher and Mr. Troyer — Democrats and Republicans still chose neighborhoods that were 24 points apart in the 2020 vote.

In the article below, we give a more detailed overview of multispectral and hyperspectral remote sensing. Let’s get started.

Mr. Troyer, a Republican, on the front porch of his home outside Minneapolis, in a neighborhood that voted for Mr. Trump in 2020 by a wide margin.

While when it comes to hyperspectral data, images present hundreds of points of each band hence much more detail to observe. The wavelength is split into numerous narrow bands that capture a unique spectral fingerprint or signature of an object. Therefore, the images captured contain much more data, thus preventing any analyst from the potential to detect differences among land and water features.

Plane ofpolarization

In Arizona, a state Mr. Biden won by less than 12,000 votes, incoming Republicans — a third of them from California — outnumbered incoming Democrats by a margin of three to two. Accounting for departures, Arizona gained about 17,000 Republican voters.

In multispectral remote sensing, each pixel has a discrete sample spectrum. For example, some wavebands may have 4 to 20 data points per pixel.

“For the most part, you just kind of kept to yourself,” Mr. Fisher, a South Dakota native, said of his old neighborhood, a precinct Mr. Biden won by five points. He says he feels more comfortable in his home in southwest Charlotte, in a precinct Mr. Biden carried by 46 points. “It’s definitely bluer than where we were before, and kind of a nice change,” he said.

It also has real stakes for our elections: Political scientists say the more partisan a district or state becomes, the less a candidate needs to woo voters from the other party — or, after winning, govern on their behalf.

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Romance was also a factor for Andrew Clohessey, 35, who moved to Minneapolis in 2021 from Cedar Falls, Iowa. He’d spent the previous year deliberately applying for jobs in liberal cities, eager to get out of an area that felt increasingly conservative to him, even though his precinct voted for Mr. Biden. He moved into a neighborhood with a lot of shops within walking distance, one that Mr. Biden carried by 61 points. “It’s been great,” he said. On dating apps he is now “more likely to match with people who have left-leaning political views.”

On the other hand, hyperspectral remote sensing is a technique that analyzes a wide spectrum of light instead of just assigning primary colors to each pixel. Its primary goal is to obtain a spectrum from each pixel in the image of a scene to find objects, detect processes, or identifying materials. Hyperspectral remote sensing samples a wide variety of bandwidths in the light spectrum. This aims to provide a rich dataset and detect objects of interest not visible to single-bandwidth imaging sensors.

On the other hand, hyperspectral remote sensing has a high spectral resolution that makes it possible to detect the spectral properties of objects and minerals. It gives the better capability to see the unseen.

Mr. Fisher, the Democrat, said that while he was eager to escape the snow, he also found the local politics increasingly oppressive. An outspoken liberal, with bumper stickers on his Jeep to match, he was eager to find a place that better reflected his sensibilities.

In 36 states, polarization happened in both directions at once: More newcomers were of the winning party, and more of those who left were of the losing party.

On the other hand, hyperspectral imaging can detect thousands of different bands within the light spectrum. Sich imagery is extremely helpful to detect certain objects and minerals if an analyst is familiar with their spectral properties. Just like multispectral, their satellites also follow the sun-synchronization, Low Earth Orbit.

Meanwhile, hyperspectral imaging makes it possible to collect several hundred spectral bands in a single acquisition. Such a feature has made it expensive as it demands more technological advancement to produce more detailed spectral data. With this comes issues related to increased sensor and image costs, data volumes and data-processing costs, and high demand to maintain operations.

Multispectral and hyperspectral are types of spectral imaging with similar technologies. They are distinct imaging methods in that they each have their own application spaces. Such application spaces have evolved to include; remote sensings like map species, mineral exploration, food engineering, agriculture, atmospheric studies, ecology, health care, and agriculture.

California has contributed to this trend in a different way: by exporting Republicans en masse. More Republicans have moved out of California than any other state. And those who did have made other states redder in the process — particularly Texas, Arizona, Florida and Nevada.

On the other hand, hyperspectral imaging technology is facilitated by the high informational content hence continuous development. It is therefore positioned to become a primary remote sensing technology used on a global scale.

Consider Florida: Once a critical swing state, it has become more reliably Republican. Out of the 3.5 million voters we tracked, more than 200,000 registered Republicans have moved in over the past four years, more than twice the number of Democrats.

It’s unclear how much of a direct effect movers might have on the election. Each cycle, the electoral landscape changes in ways that have nothing to do with moving: People turn 18; people die; people change their minds or decide not to vote. But in an extraordinarily close race, even small shifts could prove decisive.

Across all movers, Republicans chose neighborhoods Donald J. Trump won by an average of 19 percentage points in 2020, while Democrats chose neighborhoods President Biden won by the opposite margin (also 19 points). In total, movers started in neighborhoods 31 percentage points apart; they ended in neighborhoods 38 points apart. Across the country, the result is a widening gap between blue neighborhoods and red ones.

Our analysis and interviews suggest just how intertwined political and lifestyle choices can be when it comes to choosing a new home, particularly since 2020.

Polarizationexamples

This is just one pair of voters, but they are part of a trend. Consider the moves of Republicans from relatively balanced neighborhoods like theirs:

Polarizationcharacteristics

Our analysis suggests partisanship itself, intentional or not, plays a powerful role when Americans uproot and find a new home. And their very personal decisions about where to resettle help power the churn of migration that is continuously reshaping American life at the neighborhood level and contributing to a sense that Americans are siloed in echo chambers, online and in their daily lives.

High racial diversity means a census tract has a diversity index at the 75th percentile or above. Walkability ratings come from the E.P.A.'s National Walkability Index. Forests include all land classified as a deciduous, evergreen or mixed forest by the US Geological Survey's National Land Cover Database. Neighborhood type definitions are New York Times classifications based on Census data. Temperature data is from the National Centers for Environmental Information. Home value and property tax data from Attom.

In all but three states that voted for Mr. Biden in 2020, more Democrats have moved in than Republicans. The reverse is true for states Mr. Trump won — in all but one, more Republicans moved in.

This is just one pair of voters, but they are part of a trend. Consider the moves of Republicans from relatively balanced neighborhoods like theirs:

And yet both ended up in places that were more partisan than where they came from, a phenomenon known as “sorting.” Research on partisanship and migration has found politics typically figures into the equation only indirectly — or even coincidentally.

Tens of millions of Americans move each year, whether across town or across the country. Most of the voters in our set moved during the pandemic, when home sales surged and many Americans were ready for a change.

Multispectral remote sensing involves the acquisition of visible, near-infrared, and short-wave infrared images. These images are acquired in several broad wavelength bands. Therefore, a multispectral image captures the image data within a specific wavelength range across the electromagnetic spectrum. The different materials captured reflect and absorb differently at these different wavelengths. In this imaging method, it is possible to differentiate among materials by their spectral reflection signatures as observed in these remotely sensed images. It makes direct identification not possible.