Showing posts with label aerial photography. Show all posts
Showing posts with label aerial photography. Show all posts

January 10 - Above and Below Day

 Posted on January 10, 2021

This post is an update of my January 10, 2010, post:


On this date in 1863, the world's first underground train opened to fare-paying passengers in London. It was called the Metropolitan Railway (and is now called the Underground or the Tube). In the U.S., an underground train is called a subway.

On this date in 1911, the first aerial photograph taken in the U.S. from an airplane was taken over San Diego, California.


On this date in 1935, Amelia Earhart began a flight from Honolulu, Hawaii, to Oakland, California. When she succeeded,
landing the next day, she became the first person to have successfully soloed such a flight. Thousands of cheering fans greeted her.

Did you know...?
  • Within a few months of opening, the London Underground was carrying more than 26,000 passengers a day. (An amazing 40,000 passengers traveled on it the very first day.)

 

  • The underground train that crosses the English Channel goes through an undersea tunnel about 50 kilometers (30 miles) long, and about 75 meters (250 feet) deep at the deepest point. The Channel tunnel is called the Chunnel.

 

  • Our “aerial photos” now come from satellites in space and cover every bit of the Earth. The resolution is down to 1.3 to 2 feet per pixel. That means you theoretically could spot even a bicycle or a doghouse on the latest aerial photos!

 

  • It took Amelia Earhart 17 hours and 7 minutes to fly the 2,408 miles from Hawaii to California. Now such a flight would take about 5 or 6 hours.


Explore some aerial photos.
  • Zoom in (wait a few seconds for the picture to focus) on this photo of San Francisco.
  • Here are some splendid aerial photos of London at night. (The Big Picture is an excellent place for all sorts of photos, by the way!)


  • This video shows the Harbin Snow and Ice Festival in China - from above. Isn't it gorgeous?


Find your house in a satellite photo.


The map of the London Underground is considered a classic. It doesn't try to show things exactly where they are, since that isn't helpful. Instead, it shows the train lines and stations relative to each other, and they are clearly labeled and color coded. Many other transportation maps worldwide are based on this one.

Do a coloring page on Amelia Earhart.



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February 21 – Happy Birthday, Edouard-Gaston Deville

Posted on February 21, 2014


Have you heard of phototopography? How about photogrammetry?

Yeah, me neither! Actually, even my spell checker hasn't heard of the first one!

But actually, this field (which has two names, and which was first perfected by today's birthday boy) is really important—and even something we take for granted:

It is the use of photography to make maps.

Some descriptions of photogrammetry say that it is a non-contact method of making maps. In the past, people had to actually walk or sail in order to survey land, in order to make the measurements that assured that the map would be fairly accurate and therefore useful.


Who was Deville?

Born in France, Edouard-Gaston Deville attended naval school, served in the French navy, and learned about surveying. He moved to Canada at age 25 and began to work as a surveyor and astronomer. He was quickly promoted to top surveyor, and for many years he directed Canadian surveying activities.

So, you know what Canada is like, right? It is the second largest nation in the world, after Russia, and a lot of it is high mountains or remote Arctic lands. At the time that Deville developed new surveying techniques, in the late 1800s, there was no Google Earth or satellites in space, of course, and even the airplane hadn't yet been invented. However, photography was nearly half a century old and was revolutionizing many aspects of life. Deville wanted to use it to survey Canada's mountains in a faster, cheaper way.

He had to design a rugged but lightweight field camera that could be carried up to the top of a mountain. Once the camera was in place on a mountain peak, the surveyors pointed the camera at the horizon and took panoramic photos of the nearby peaks. Each photo shot was carefully recorded with a measurement of the angle of the camera to the survey station. Surveyors did all their measurements and took all their photos during the short Canadian summers, and during the longer winters they would make their calculations and draw their maps. The first such mountain survey was started in 1886.

It turned out that, not only were these techniques much faster than traditional surveying techniques—and cost only about a third as much—the results were more accurate. Soon Deville became a sought-after expert in mountain surveying, and people all over the world asked his advice, read his pamphlets and textbook, and copied his camera and techniques.

As you can imagine, when air flight became possible, surveyors could use Deville's camera to create aerial photos. This helped Canadian surveyors accurately map the flat-but-remote northern areas of the nation.





This is Mount Deville, named
for today's birthday boy.
It is in Yoho National Park in
Canada--and, oh, my!--is that
place GORGEOUS!!!

More on maps...

  • Check out these child-drawn maps created in the 1700s and 1800s. Students often carefully copied and colored maps in order to learn geography. Do you think the parts that don't match modern maps are inaccurate because the kids were—you know—just kids, or do you think that they were pretty accurate copies of what people knew back then?

  • Use Google Earth to create a map of your own neighborhood.



Also on this date:













Plan ahead:

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