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The best of Google Earth for February 2016

mar 01-03-2016

There have been no major imagery updates since mid-January. The latest imagery to be found in ‘historical imagery’ is dated January 11, 2016. However, Google did add an image dated February 2nd, 2016, which includes the stadium where Super Bowl 50 took place. As far as we know, it was the only image added in that update, but it has not been migrated to historical imagery, so we don’t know for sure.

There were some Street View updates, most notably the Island of Réunion, which we covered in yesterday’s post.

3D imagery continues to be rolled out and we had a look at the progress made so far.

At the end of January, Google dropped the three Google Earth Pro only layers. This was because Google Maps Engine was being shut down, as it had been deprecated a year ago. We then discovered that the Google Earth Traffic layer also depended on Google Maps Engine and was also dropped. Judging by the various comments and emails we have received, the US Parcel Data layer and the Traffic layer will be sorely missed by a number of people.

We had a look at some Google Earth animations created by Steven Ho. We especially liked the Taiwan Lantern Festival animation, as Steven managed to get the lanterns to appear to glow, even though Google Earth does not have a very sophisticated lighting engine. Try them out in Google Earth by going to his blog and specifying the coordinates you would like.

We created a number of JavaScript tools in February for manipulating KML in various ways. We started with a tool for translating and rotating KML. Then we created a tool for labelling polygons. We then tried drawing circles based on three placemarks on the circumference. At first we had a little trouble with accuracy, but were able to fix all the bugs and it now works remarkably well. We also created a tool for classifying placemarks by region and to demonstrate it we used a global map of country outlines which we first needed to convert from the shapefile format.

Frank wrote a post about Space Engine a ‘Google Earth’ for the universe. If you haven’t tried it out yet, then consider doing so, as it is definitely worth a look. It can be downloaded here.
 
 
 
 

We had a look at ghostly images in Google Earth’s 3D imagery and what causes them.
 
 
 
 

In reference to the recent detection of gravity waves by the Laser Interferometer Gravitational-Wave Observatory (LIGO), we had a look at LIGO and a variety of other large scientific instruments. We followed that up by having a look at various radio telescopes.
 
 

We had a look at NASA’s ‘damage maps’ of last year’s earthquake in Nepal.
 
 
 
 

We continued our GEB FAQ series by discussing how to add your own imagery to Street View.
 
 
 
 


We had a look at Landsat coverage and found an interesting gap at the antimeridian.
 
 
 

To celebrate Valentine’s Day we had a look at various heart-shaped islands in Google Earth
 
 
 

The post The best of Google Earth for February 2016 appeared first on Google Earth Blog.

Catégories: Sites Anglophones

Street View comes to Réunion

lun 29-02-2016

Réunion, a French Island in the Indian Ocean not far from Mauritius, has recently received Street View. We found that although the coverage shown by the blue lines is quite extensive we were not able to access it in a number of areas. For example, Îlet à Cordes shows blue lines but if you try to enter Street View there in either Google Earth or Google Maps it does not succeed.


Changes to Street View between January 28th, 2016 and February 28th, 2016. Changes marked in red. Existing Street View in blue. Large version


See it in Google Maps . With nothing to judge scale by, this volcano looks deceptively small and close. It is actually about 3 km away and has a crater over a kilometre wide at its peak. The whole thing is sitting inside a much larger crater, the edge of which the photo was taken from.


See it in Google Maps. Réunion has some very steep mountains. We thought this spot looked especially beautiful, with the sun just peeping over the mountain.

Other new Street View includes expansions to coverage in Ecuador, Bolivia, Uruguay, Brazil, The Philippines, Ukraine and Russia. And the Google LatLong blog lets us know about some US stadiums that have received Street View. There is also some new Street View of Ellef Ringnes Island in the far north of Canada. It is dated April 2014, but appears to have only recently been added.


See it in Google Maps. If Réunion was too hot and tropical for you, then try exploring Ellef Ringnes Island in northern Canada.

The post Street View comes to Réunion appeared first on Google Earth Blog.

Catégories: Sites Anglophones

Ghostly planes in Google Earth 3D imagery

ven 26-02-2016

We recently came across this story about what at first sight appears to be a plane at the bottom of a lake. Today we are looking at how this ‘ghosting’ effect comes about.


The two ‘ghostly planes’ noted in the article above.

We have previously discussed the ‘rainbow effect’, which has even inspired artists. That is caused by the way satellite cameras work, taking multiple photos in quick succession with different colour filters.

However, the planes in this case are in 3D imagery, which is not captured by satellites, but from aircraft. An aircraft flies over a region capturing multiple images in succession. It then comes past again at a later time and captures more images. In this post we noted that a water tower had been photographed from six different directions at two different times of day. Next Google uses an algorithm that uses the stereoscopic effect to reconstruct the 3D shape of objects. However, this fails for moving objects. At airports we often see aircraft that were captured well from one side but had left or moved before the other side was captured and they end up looking hollowed out.


Planes that moved before all the second set of images were captured.

Vehicles have a similar problem:


You can read the number on the roof of the bus, but the rest is a ghost.

The technique used for reconstructing the 3D has particular problems with water. The surface of the water is constantly changing, which confuses the algorithm. Uniform surfaces with no markings also give problems. Google often completely turns off the 3D generation for large rivers, lakes and the sea. However, they still have multiple photos for each location, which the blend together. As we showed you in this post, this can lead to some interesting effects.

Based on carefully studying of a location in Venice, Florida, USA, we believe that there are four images captured in fairly quick succession, followed by another four at a later time, resulting in anchored boats appearing to have eight copies altogether, but moving boats only appear to have four images, unless you can figure out where they were on the second pass. There are also some much less distinct images for each boat, but they are harder to count or work out when they were captured.


Each boat has 8 distinct images as well as other less distinct images.

From the boat track below we can see that there is quite some time between each individual image:

An aircraft in flight, such as the ones at the beginning of the post, is so fast that it will only be captured once and thus appears fainter than most of the other images we have featured above.

To see the locations featured in this post in Google Earth download this KML file. Be sure to turn on the 3D buildings layer to see the imagery.

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Catégories: Sites Anglophones

Classifying placemarks by region

jeu 25-02-2016

As we mentioned in yesterday’s post we have been working on a bit of code to determine whether or not a placemark lies inside a polygon. We believe we have got it working and thought it might be useful for people who want to classify placemarks by region. So, we have created the JavaScript-based tool below.

To use it, simply upload a set of placemarks and polygons and it will check what polygons the placemarks are in and put them all in folders named after the polygons and give you back a KML file with all the placemarks nicely categorised. As an example, we found this map of nuclear power plants on the Google Maps Gallery. We opened it in Google Earth to get the KML version, then used both it and the country borders we showed you yesterday to classify all the nuclear power stations by country.

It accepts multiple files so you can have your placemarks in one file and regions in another. It can be quite slow for large datasets. The above datasets took about 3 minutes on a fast computer.
[ Update: We have fixed a few bugs and added some optimizations which has improved the performance significantly.]

input,select{padding:4px;color:black;border:none}input[type="file"]{width:250px;}

Include empty regions

Classify placemarks

As usual we have not yet tested it thoroughly and make no guarantees that it will work perfectly. The country outlines are not very high resolution so placemarks near borders may be incorrectly classified. Let us know about any bugs you find or enhancements you would like to see, in the comments below.


Once the placemarks are classified it is easy to select only one folder.

We were also able to use it to make an approximate list of the number of nuclear power stations per country. Note that the list includes both active and inactive power stations and lists individual reactors not sites. For example Pickering in Canada has 8 reactors. We also do not know how old the list is.

The biggest problem is that nuclear reactors are often near coastlines and as mentioned above, the country outlines are not very high resolution and many of the nuclear reactors are outside the country borders. So, of the 766 reactors in the original file, only 578 were successfully classified.

#countryTable td ,#countryTable th { text-align: right } #countryTable th{vertical-align:initial;padding-left:14px;} #countryTable td:first-child ,#countryTable th:first-child { text-align: left;padding-left:0px; } #countryTable {font-size:10pt} Country # of reactors Armenia 2 Argentina 5 Australia 1 Bulgaria 5 Canada 24 China 22 Cuba 1 Czech Republic 9 Finland 2 France 71 Germany 32 Hungary 5 India 22 Iran (Islamic Republic of) 3 Israel 1 Italy 3 Iraq 1 Japan 45 Korea, Republic of 8 Lithuania 1 Slovakia 6 Mexico 1 Belgium 9 Netherlands 1 Romania 3 Russia 60 Slovenia 2 Spain 16 Sweden 9 Switzerland 11 Ukraine 22 United States 168 Taiwan 7

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Catégories: Sites Anglophones

Converting Shape files to KML with Google Earth Pro

mer 24-02-2016

We have been working on some code to determine whether or not a placemark lies inside or outside a polygon. We thought a nice use for that code would be to determine what country a placemark is in. For this we required the outlines of countries in KML format. We discovered ThematicMapping.org has a map of country outlines provided here. The Thematic Mapping API is a brilliant JavaScript API to help you create KML based thematic maps. See here for some of our previous posts about it.

The world country map is provided in what is known as the shapefile format. It is a popular format developed and maintained by Esri for use in GIS products. Google Earth Pro, it turns out, has built-in support for importing shape files. Simply go to File->Import then select “Esri Shape (*.shp)” from the file types list. Google Earth Pro then asks you if you want to apply a style template to the features you just ingested. We found that if we chose not to do so then all the shapes were named ‘[no-name]’. So, instead we chose to apply a style template which gives us the option to name the polygons from a field in a table of data included in the shapefile. One of the columns contains the country names, so we used that. There is also an option to colour the shapes based on a field in the data, all a single colour or random colours. We chose random colours. You can also set the icons and heights from fields in the data, but neither was appropriate in this case.


GEB reader Clare has noted that the map is a bit out of date with Sudan shown as a single country.

Once imported, if you click on one of the countries it shows a popup with some basic data about each country, such as name, area and population figures from 2005, which were contained in the shapefile. It is also now possible to save the dataset as a KML file. The resulting file is a little large, at 10.7MB, but compresses down to less than a third of that size when saved in the compressed KMZ format.

The original shapefile is shared under the Creative Commons ShareAlike licence, so you are free to use it on condition you give proper attribution to the original source. So, if you want some country outlines for use in Google Earth here is the KMZ version.

We have also created this version with all the extra country information removed, as well as changing the styles so as to only show country outlines.

The post Converting Shape files to KML with Google Earth Pro appeared first on Google Earth Blog.

Catégories: Sites Anglophones

Celebrate Chinese Spring Festival in Google Earth

mar 23-02-2016

Here at GEB we have traditionally celebrated the new year with a Google Earth fireworks animation created by Steven Ho. This past new year we decided to expand on the idea by allowing you to create fireworks at the coordinates of your choice. This, in turn, has inspired Steven Ho to create a new animation to celebrate the Chinese Spring Festival, (also known as Chinese New Year or Lunar New Year).

His animation shows Chinese couplets falling from the sky, with the camera slowly rotating around the location you select – all set to music. Chinese couplets are a popular form of Chinese poetry that consists of a pair of lines of verse that match up in a number of different ways. You can learn a bit more about them on the Wikipedia page. They are popular for decorating doorways and also often used during celebrations, such as the Chinese Spring Festival.

He has also created a similar animation for the Taiwan Lantern Festival, which shows lanterns flying up into the sky at night.

To see YouTube videos of both animations and create animations for the location of your choice, see the full post on Steven’s blog.

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Catégories: Sites Anglophones

Google Earth 3D imagery progress

lun 22-02-2016

Google continues to push out new 3D imagery on a regular basis. However, an increasingly large proportion of it is updates to areas that already had 3D imagery. The updated areas are generally better quality and certainly welcome, but it does mean there is a noticeable decline in the amount of new area covered each month.


New area in square kilometres of 3D imagery covered by month. Note that we have not yet included all of the January and February, 2016 areas.

To see the area covered by 3D in Google Earth download our KML map.

We used to use the helpful online tool at Zonum Solutions to calculate the areas. However, it has a file size limit that our KML file has exceeded and a few other issues which make using it for our particular requirement quite tedious. So this time we used the area functions found in GeographicLib to do the calculations.

The US has almost double the area of 3D imagery of the rest of the world put together.

#countryTable td,#stateTable td ,#countryTable th,#stateTable th { text-align: right } #countryTable th,#stateTable th{vertical-align:initial;padding-left:14px;} #countryTable td:first-child ,#countryTable th:first-child,#stateTable td:first-child ,#stateTable th:first-child{ text-align: left;padding-left:0px; } #countryTable,#stateTable {font-size:10pt} Country Km2 Argentina 1,417 Australia 3,578 Austria 2,717 Belgium 2,511 Brazil 5,114 Bulgaria 1,946 Canada 13,145 Chile 1,146 China 158 Czech Republic 3,262 Denmark 1,326 Finland 860 France 22,012 Hungary 3,062 Germany 17,989 Greece 911 Ireland 197 Italy 19,799 Japan 14,069 Kosovo 82 Luxembourg 126 Malta 176 Mexico 4,614 Montenegro 81 Netherlands 294 New Zealand 706 Norway 4,641 Philippines 714 Poland 2,858 Portugal 5,455 Puerto Rico 638 Romania 2,518 Spain 17,690 South Africa 1,458 Sweden 1,285 Switzerland 4,043 United Kingdom 11,195 United States 325,290   US State Km2 Alabama 8,575 Alaska 580 Arizona 8,394 Arkansas 3,671 California 35,875 Connecticut 2,790 Colorado 6,321 Delaware 525 Florida 25,144 Georgia 12,730 Hawaii 956 Idaho 1,646 Illinois 6,698 Indiana 6,797 Iowa 3,718 Kansas 4,789 Kentucky 2,723 Louisiana 5,970 Massachusetts 7,610 Maine 1,968 Maryland 2,106 Michigan 10,192 Missouri 5,317 Minnesota 6,693 Mississippi 4,392 Montana 1,348 Nebraska 1,696 Nevada 2,244 New Hampshire 1,513 New Jersey 2,509 New Mexico 2,111 New York 11,895 North Carolina 14,638 North Dakota 1,106 Ohio 10,107 Oklahoma 3,872 Oregon 5,404 Pennsylvania 7,700 Rhode Island – Tennessee 10,400 Texas 27,524 South Carolina 9,405 South Dakota 796 Utah 4,594 Vermont 261 Virginia 7,348 Washington 9,166 Wisconsin 9,914 West Virginia 2,347 Wyoming 1,212

Note that some 3D areas overlap borders and the areas are recorded in the country/state where the bulk of the 3D lies. So Rhode Island State, for example, does have 3D imagery but it is part of a large area mostly in Massachusetts.

Thank you to all the GEB readers that find new areas and a special thanks to the GEB readers who draw new areas for inclusion in our map. New areas are noted in the comments of this post. If you wish to submit outlines please first read through the instructions found here.

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Catégories: Sites Anglophones

Fixing our circles

ven 19-02-2016

Earlier this week we posted a JavaScript tool for drawing circles in Google Earth. We noted that it didn’t seem to be accurate and assumed it was because some of the calculations were being done by approximating the Earth as a sphere.

Thank you to GEB reader DJ for trying it out and letting us know about a bug which resulted in this interesting pattern:

We decided to investigate and try and improve the accuracy of the code as well as fixing the above bug. We ended up finding a number of bugs. The first, is that for drawing circles, we had reused some code we wrote for drawing fireworks to celebrate the new year. The code correctly took into account the fact that latitude and longitude vary in scale, but apart from that used basic trigonometry to draw the circle. This works very well on small scales, but for very large circles problems become obvious, and if you draw a circle over one of the poles it wraps around it as seen below:

A second bug was due to the fact that in geodesic calculations there are two angles that are typically very similar and we were using the wrong one. This tends to only show up over large distances, so it is not something you notice immediately.

Finally, for the code to calculate intersections we decided to stop using the code from Movable-Type, which uses spherical geometry and instead used some code by Charles Karney posted here. The code was intended to be used with the C++ version of GeographicLib so we had to do some translation into JavaScript.

The result of the above corrections is still not perfect, but is certainly a lot more accurate than it was. There is still a bug that causes it to fail when the triangle is very large, but we hope to get that fixed over the weekend.

For those interested in the code:

Our code is written in the latest version of JavaScript, ES6, which works fine in Chrome, but we convert it to ES5 using Babel for greater cross-browser compatibility before using it on the site.

The post Fixing our circles appeared first on Google Earth Blog.

Catégories: Sites Anglophones

Space Engine – to Infinity and Beyond

mer 17-02-2016

I still remember the first time I used Google Earth and how my sense of wonder grew as I realized the amazing capabilities of the program to portray our planet Earth at new levels of detail with a huge source of data both in aerial imagery, but also in 3D. It has been a long time since I found a program which generated the same sense of wonder. Until now.

Space Engine

I recently ran across an application called Space Engine which was reported to produce amazing visualizations of space and let you tour not only our solar system and nearby stars, but also stars throughout the Milky Way. Even better, the developer uses an algorithm to create planets, moons, asteroids and comets for as many star systems as astronomers currently believe exist, throughout our galaxy. Beyond that, Space Engine generates them for galaxies throughout the universe as we know it. So, you can literally visit trillions upon trillions of stars and planets (if you had enough time!) for endless galaxies. When you visit a planet, moon or asteroid’s surface, the program procedurally creates 3D terrain and textures to make the surface appear more realistic. To put this in perspective, this program lets you have an entire Universe to explore inside your own computer. Wow! However, it does require a relatively powerful desktop computer (or gaming laptop) with a beefy video card to run well (see the minimum specs in the download link at his web site).

My feeling was just as enthusiastic viewing Space Engine as the first time I saw Google Earth. What really amazed me was seeing the beauty of our universe when portrayed using more current graphics technology, and the endless sense of exploration to discover new worlds. Space Engine allows you to experience the awe and wonder of the Universe and capture your memories to share with others.

Space Engine uses data from dozens of astronomical databases to accurately portray the physical characteristics for all the known systems. It also extrapolates the characteristics for stars and planets beyond to fill our galaxy and other galaxies based on theoretical compositions. You can easily see the physical characteristics (size, mass, gravity, atmosphere, temperature extremes, and whether a planet could support life). In a sense it is more of a sandbox simulation, or a game, than a mirror of our universe.

It’s important to note that your movement in Space Engine isn’t limited by silly physical laws like the speed of light, so you are able to travel to other systems throughout the Universe in very reasonable amounts of time. If you were limited to our current technological and scientific abilities, and our understanding of physics (not being able to travel faster than the speed of light), it would take decades or centuries to even reach the nearest star systems to Earth.

I had plans for creating my own video demonstration of this application. But, I keep getting engrossed in the program. So, I’m sharing one of several YouTube videos about Space Engine to give you a taste of the experience. If you have dreamed of space flight, like I have, then you will most likely have the same reaction of awe and wonder that I do every time I use Space Engine. Watch this video demonstration by a gamer called Obsidian Ant who is just as amazed:

To make Space Engine more like a game, the developer has chosen to allow its users to add space ships and controls so you can fly through space as if you were an explorer and visit places. You can really get a sense of dimension when you compare objects next to a spaceship. The developer has even added support for virtual reality by supporting the Oculus Rift – so you can really immerse yourself in this universe.

Spacecraft near a moon

Like with Google Earth, Space Engine lets you click at a place (a star or other object you see in the background) and see information about it. Then, you can click a button and choose to simply fly to that location and get a closer view. Using various controls (including that Space Navigator, mouse, keyboard, joystick or even flight sim controls) you can easily move around the various astronomical objects and get better views. You can even land on them. I find myself regularly taking screenshots (like photographs) of the amazing views I see in this program! I have long used space art as a desktop background on my computers, and now I have an endless supply of views that are as good or better than those I’ve used before. If you search Google Images, you can find many thousands of screenshots from this program on the Internet.

Also like Google Earth, you can save a place you are viewing like a placemark and visit again at a later time, or share it with your friends. So, in many ways, Space Engine has abilities like Google Earth, but extrapolates its range to the whole universe, not just our home planet. But, Google Earth remains the king when it comes to portraying our home planet (both in terms of realism, but also in terms of the amount of data about Earth). Google Earth’s Mars and Moon modes also have far more data than Space Engine about those bodies. Space Engine has prettier views though, because it uses more recent graphics technologies and isn’t limited to near-surface viewing like Google Earth.

What’s really amazing about Space Engine, is that it was created, and continues to be developed, by a single person. Vladimir Romanyuk is a software engineer who lives in Russia. He has not only developed this application, but also architected his own universe using his knowledge of software and astrophysics. He does get help from an active community for space ship models, feedback, and contributions towards planetary models and textures. His software is not officially released yet – latest beta version is 0.9.7.4. But, judging by his fans, and my experiences, this freely available program is getting close to ready for broader use. According to his community forums he is planning to release a version of Space Engine for the Steam game platform soon which will greatly increase its exposure.

I should mention that there are some comparable commercial space games out there which already have a more robust gaming architecture for space travel with thousands of active users. The most popular and comparable one I’ve seen is Elite: Dangerous. Space Engine exists, in part, because of the much older pioneer in this genre of a free program called Celestia which also let you explore space and even allows people to create educational tours. I used Celestia many years ago as well and mentioned it in early days of Google Earth Blog posts, but the application has not been worked on for a long time. If you don’t have a fast enough computer for Space Engine, you can probably download and run Celestia (Windows, Mac, and Linux) and enjoy its more limited capabilities.

Many thanks to Vladimir for his fantastic work with Space Engine. He has done something I always thought would be the next step after Google Earth and even discussed with Google. I wish Vladimir the best success as he introduces his universe to a wider audience and continues to astound us with future features and data. His application right now is a real joy to experience. It may be a little tricky to learn the more advanced features, but the Space Engine forums can help you figure things out. Space Engine only runs on Windows right now, but he’s asking for donations to help him add new features and versions for Mac and Linux. He has recently uploaded his latest version to 0.9.7.4 RC1 (release candidate 1). Download here (note the file size shown on the page).

All of the screenshots in this post came from Space Engine with permission from it’s developer.

Purple Nebula Backdrop

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Catégories: Sites Anglophones

Drawing circles in Google Earth

mer 17-02-2016

In our recent post about LIGO and other large scientific instruments we mentioned that the Large Hadron Collider (LHC) at CERN in Geneva, Switzerland is underground. We know that it is circular and we were able to identify several buildings on its circumference. We would have liked to use that to draw a circle showing the location of the LHC. However, Google Earth does not have an option to draw circles. There are a number of tools on the web that will create a circle, given the coordinates of the centre and a radius, but in this case we don’t know where the centre is.

So, we thought it might be useful to have a tool that can draw a circle, given any three points on its circumference. It turned out to be more difficult than we expected, as trigonometry on the surface of the Earth is quite complicated. In two dimensions, the basic concept is easy; you just draw a triangle based on the three points, bisect the lines and where they intersect should be the centre. We used the same process but each of the steps has to be carried out using rather complicated formulas because of the curvature of the Earth. We used two different JavaScript libraries as we needed functionality from both. For distances and bearings we used GeographicLib, which is a popular open source library for geographic calculations. However, the current JavaScript version of GeographicLib does not include a method of finding the intersection of two geodesics so for that we used Geodesy from Movable-Type.

The results are not very accurate so if anyone knows a better algorithm for finding the centre of a circle on the surface of the Earth please let us know in the comments.


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To create a circle simply create a KML file with three placemarks, upload it below and click ‘Create Circle’.

Show calculations.

Create Circle

To create a circle that you know the centre of, create a placemark at the centre and name it ‘centre’ and create a second placemark on the circumference. Then upload it above and click ‘create circle’.

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Catégories: Sites Anglophones

Radio Telescopes in Google Earth

mar 16-02-2016

Yesterday we had a look at some very large scientific instruments that can be seen in Google Earth. Today we are looking at telescopes. Optical telescopes come in sizes up to 10m in diameter, which is very large for an optical telescope, but not very large from the point of view of satellite imagery. Radio telescopes on the other hand, can be a lot larger.

The largest single dish radio telescope is the Arecibo Observatory in Puerto Rico with a diameter of 305 m.


Arecibo Observatory, Puerto Rico

China is building an even larger dish, the Five-hundred-meter Aperture Spherical Telescope (FAST) which, as the name suggests, will have a diameter of 500 m.


Five-hundred-meter Aperture Spherical Telescope (FAST), Guizhou Province, China

Large, movable dishes are also common. Below is the Effelsberg 100-m Radio Telescope.


Effelsberg 100-m Radio Telescope, Germany

Radio telescope arrays consist of a number of dishes spread out over a large area.

We start with the Giant Metrewave Radio Telescope in India. It consists of 30 separate dishes arranged in a ‘Y’ shape. Below we see the cluster of dishes at the centre of the ‘Y’.


Some of the dishes of the Giant Metrewave Radio Telescope

To see the whole ‘Y’ shape we have to zoom out to where the individual dishes are no-longer visible, so we have marked them with placemarks. It measures approximately 25 km between tips.


The layout of the Giant Metrewave Radio Telescope.

Next is the Karl G. Jansky Very Large Array (VLA), New Mexico. It is also in a ‘Y’ shape and has longer arms than the Giant Metrewave Radio Telescope above. Each arm has a railway line and the dishes can be moved along the arms to focus on different frequency ranges. Below you can see all the dishes have been brought to the centre. Be sure to check the historical imagery to see the dishes spread out all the way to the ends of the arms.


Karl G. Jansky Very Large Array (VLA), Plains of San Agustin, New Mexico.

The Square Kilometre Array stretches all the way from South Africa to Australia. The name refers to the total area of all the dishes in both countries once it is completed (one square kilometre). Below we see part of the South African site known as MeerKAT imaged in 2013. We could not find any actual dishes at MeerKAT but the foundations for dishes have been constructed. The image only shows the central part, so be sure to explore the site further in Google Earth. We have also identified the Australian site, which does have a lot of visible dishes that we have marked in the KML at the end of this post.


MeerKAT, South Africa

The Siberian Solar Radio Telescope consists of 256 dishes arranged in a cross:


The Siberian Solar Radio Telescope

Not all radio telescopes are dishes. There are a variety of other patterns, such as the Precision Array for Probing the Epoch of Reionization, which is located near the MeerKAT site in South Africa.


Precision Array for Probing the Epoch of Reionization, South Africa

The Low-Frequency Array for Radio astronomy (LOFAR) in the Netherlands has an interesting pattern. Below we see the central circle, but it extends quite a way outwards in an interesting pattern with sets of three dots. It can only be seen in ‘historical imagery’ because the default imagery is from 2005 before it was built.


Low-Frequency Array for Radio astronomy (LOFAR), the Netherlands

Another interesting design is the Nançay radio telescope in France.


Nançay radio telescope, France

To see the above locations, as well as a variety of other Radio Telescopes in Google Earth download this KML file.

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Catégories: Sites Anglophones

LIGO and other large scientific instruments in Google Earth

lun 15-02-2016

The biggest news in science recently is the detection of gravity waves by the Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Virgo interferometer. You can learn more about it in this YouTube video. LIGO actually consists of two separate observatories in the US, and the Virgo interferometer is a single instrument in Italy. All three are ‘L’ shaped, with the two LIGO instruments measuring 4 km on each arm and Virgo measuring 3 km on each arm.


The LIGO detector in Washington State.


The LIGO detector near Livingston, Louisiana.


The Virgo interferometer, Italy.

Another similar instrument is GEO600, located near Sarstedt, Germany. It is quite a bit smaller, with arms 600 m long.


GEO600, Sarstedt, Germany

Another type of large scientific instrument is the particle accelerator. The most famous is the Large Hadron Collider (LHC) at CERN in Geneva, Switzerland. However, the LHC, like most other particle accelerators is underground and we can only identify a few related buildings on the surface. There are some particle accelerators that do have significant structures above ground, which you can see in Google Earth. Fermi National Accelerator Laboratory (Fermilab), in Illinois, has an accelerator known as the Trevatron, which has a circumference of 6.86 km. It is no longer operating.


The Trevatron particle accelerator.

Brookhaven National Laboratory on Long Island, New York has a number of different rings that can be seen:


1 The largest ring is the Relativistic Heavy Ion Collider.
2. The Alternating Gradient Synchrotron.
3. The National Synchrotron Light Source (circular building just to the right of the marker).
4. The National Synchrotron Light Source II.

Telescopes of various types are also highly visible scientific instruments but we will keep those for another post.

For the locations featured in this post download this KML file.

If you know of any other large scientific instruments clearly visible in Google Earth, let us know in the comments.

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Catégories: Sites Anglophones

Celebrate Valentine’s Day with Google Earth

ven 12-02-2016

This Sunday is Valentine’s Day. As we do each year we are sharing this collection of heart shapes to be found in Google Earth, which you can also see in this YouTube video. To add to that collection we found a few heart-shaped islands:

Clockwise from top left: 1. Galešnjak, Croatia, 2. Heart Reef, Great Barrier Reef, Australia, 3. Tavarua, Fiji, 4. Makepeace Island, Australia, 5. Anfi, Las Palmas, Spain, 6. Tung Talay Luang, Thailand.

You can view them in Google Earth with this KML file.

The largest known heart in the solar system is actually on Pluto and you can view it in Google Earth with this KML file.

The post Celebrate Valentine’s Day with Google Earth appeared first on Google Earth Blog.

Catégories: Sites Anglophones

Labelling Polygons in Google Earth

jeu 11-02-2016

We were recently asked by a GEB reader whether or not it is possible to add labels to paths and polygons. The ability to add labels to paths was added to KML with version 6.1 of Google Earth. Unfortunately, it cannot be done within Google Earth but requires editing the KML file. You need to identify the style element for the lines you want labels for, and add <gx:labelVisibility> in a <LineStyle>. See the KML Reference for more.

For polygons, however, there is no way to tell Google Earth to display the label. The only solution is to create a separate placemark for each polygon with the name. This can be quite tedious for large datasets, so we thought it might be useful to have a utility to do it automatically.

The utility below simply goes through a KML file and for every polygon, creates a new placemark in the centre with the same name as the polygon.


input,select{padding:4px;color:black;border:none}input{width:100px;}input[type="file"]{width:250px;}

Add Labels

Our KML parser is still in development so it is not guaranteed to keep all elements in the KML file. Let us know in the comments if you find any bugs or have suggestions for improvements.


We tested it on our map of 3D imagery.

We previously wrote a JavaScript utility to put numbered labels on the points of polygons.

The post Labelling Polygons in Google Earth appeared first on Google Earth Blog.

Catégories: Sites Anglophones

Landsat coverage

mer 10-02-2016

The Landsat 8 satellite circles the earth in a near polar orbit. See this YouTube video to see an animation of the path it takes. The resulting images are captured in specific spots on the surface of the earth laid out in rows and slightly diagonal columns, which the USGS has numbered and calls the Worldwide Reference System 2 (WRS-2). WRS-2 has been used for Landsats 4,5,6 and 7. Landsats 1,2 and 3 used WRS-1. You can download a KML file here showing the outlines in Google Earth.

Because the Landsat orbit is slightly tilted with respect to Earth’s axis of rotation, the poles are not covered. Strangely, there is also a gap at the antimeridian (the 180th meridian). We don’t know what the reason for the gap is, as the satellite clearly does fly over the anti-meridian. This becomes very noticeable if you turn on ‘historical imagery’ and look at the South Pole:


You can see in brighter white the area not covered by Landsat imagery as well as the odd gap at the antimeridian.

As we have mentioned before, Google Earth has an imperfect join at the antimeridian and if you follow it you will notice a number of glitches in the imagery and there is even a noticeable line in the ocean floor data.


Noticeable glitches in imagery at the antimeridian.

The post Landsat coverage appeared first on Google Earth Blog.

Catégories: Sites Anglophones

Adding pictures to Street View

mar 09-02-2016

This is part of a series of posts expanding on our Google Earth Blog FAQ.

We get quite a lot of email along the lines of: “Our business / rental property / property for sale is shown in Street View when it was under construction / being renovated and we feel this is negatively impacting us. Please update the Street View.” Google, however, does not capture Street View on demand and for good reason – they would be inundated with requests. But there is nothing stopping you from adding your own pictures to Google Maps and Google Earth and in most situations they will be treated with a greater priority than Street View imagery.

If you already have some good photos of the location, you can easily add them with Google Maps. Simply open the location in the Google Maps side panel either by searching for it or clicking on the place marker. Next, click ‘Add a Photo’ which appears both in the sidebar and as the last item in the list of photos. You can then upload your photo. Google Maps then shows a notice saying your photo will soon be available to be seen by the public. We assume that there is some sort of verification process to ensure that unsuitable photos are not displayed.

We found that you cannot add photos by this method to locations that do not already have markers.


Select a marker on the map (1) and then click ‘Add a Photo’ (either (2) or (3)

An alternative method is to use a smart phone and Google’s Street View app (Android iPhone). This will allow you to take panoramic photos and upload them to Street View with ease. Be sure to turn on your GPS for proper georeferencing. We believe that photos uploaded this way do not need to be attached to a placemark.

For more advanced options see this page from Google which also includes this interesting YouTube video, which has some interesting information about the trekker and how Street View is captured with it.

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Catégories: Sites Anglophones

Rotating and Translating Placemarks, Polygons and Paths

lun 08-02-2016

The Google Earth placemarks and drawing tools assume that whatever you are marking or drawing is in a fixed geographical location. Although you can move individual placemarks or individual points on a polygon or path, you cannot move multiple items at once, or even move a whole polygon or path.

We recently got an email from one of the pilots of the Geico Skytypers Airshow Team. They plan their airshows in part with the aid of Google Earth and when they want to do a show at a new airport they have to recreate all the placemarks and paths again. So, they asked whether there is a way to move a group of placemarks and paths to a new location. We have recently been developing a JavaScript KML library for our own use and thought this would be a good way to test it. So we have created a small tool that allows you to take any set of placemarks, polygons and paths and move them to a new location. You can also, optionally, rotate them about a point.

To use it, simply create a placemark nameed ‘from’ near the objects you want to move. Then create a new placemark named ‘to’ where you want them all moved to. Then save them all, including the new placemarks a KML file. Upload it below and click ‘Translate’. It should download a new KML file with all your placemarks, paths and polygons moved to the new location. The way it works, is it calculates the distance and bearing from the ‘from’ placemark to each latitude and longitude pair in the KML file. It then calculates the same distance and bearing from the ‘to’ placemark and moves the latitude and longitude pair to that location. So everything is moved in relation to the ‘to’ and ‘from’ placemarks. This avoids the distortion you would expect if you simply add a fixed amount to the latitudes and longitudes.

Rotation is achieved via two possible mechanisms. The easiest is to simply type in the rotation angle below. Alternatively, create two paths labelled ‘from’ and ‘to’ with just two points each and include them in the KML file. The tool will work out the angle between the two and use that as the rotation angle. So, for example, if you want to move a set of placemarks from one airport to another while maintaining the alignment with the runway, you put the ‘from’ path along the runway of the airport you are moving from and the ‘to’ path along the runway of the airport you are moving to, and everything should line up. The point of rotation is the ‘to’ placemark.

input,select{padding:4px;color:black;border:none}input{width:100px;}input[type="file"]{width:250px;}

Optionally rotate clockwise by:

Translate

Do not rely on the results – double check everything. We take no responsibility or liability, for any damages resulting from the use of this tool. It has not been tested very thoroughly and is not guaranteed to be accurate. Our KML parser is incomplete and may exclude some elements. It tries to translate more than just placemarks, paths and polygons, but some will not work perfectly. Image overlays, for example, do not work properly. The ‘Camera’ and ‘LookAt’ elements are translated but may not be quite right. The JavaScript works entirely in the browser so your KML is never uploaded to our server.


Create ‘from’ and ‘to’ placemarks.


Everything is moved relative to the ‘from’ and ‘to’ placemarks.


‘From’ and ‘to’ guidelines let you rotate and easily line up with geographic features.


Remember that the translation and rotation are still relative to the placemarks. The guidelines only determine the angle of rotation.


If you put the ‘from’ and ‘to’ placemarks in the same spot you can rotate around that point.

If you find any bugs, or have suggestions for further enhancements, please let us know in the comments.

See here for a variety of other JavaScript utilities we have made for working with KML.

The post Rotating and Translating Placemarks, Polygons and Paths appeared first on Google Earth Blog.

Catégories: Sites Anglophones

Super Bowl 50 in Google Earth

ven 05-02-2016

The Super Bowl is one of the largest annual sporting events in the USA. Super Bowl 50 takes place this Sunday at Levi’s Stadium in Santa Clara, California.

Google has recently done an imagery update and the latest image for the stadium is dated February 1st, 2016. The image is not yet in ‘historical imagery’. To see it, locate the stadium and turn off the 3D buildings layer.


Levi’s Stadium February 1st, 2016.


Levi’s Stadium in 3D.

Levi’s Stadium was also host to Wrestle Mania 31 in March 2015 and the event can be seen in Google Earth historical imagery:

To find the stadium and a few other stadiums from past Super Bowls in Google Earth, download this KML file.

We have also looked at various other Super Bowl stadiums in the past.

The post Super Bowl 50 in Google Earth appeared first on Google Earth Blog.

Catégories: Sites Anglophones

Google Earth Traffic layer dropped

jeu 04-02-2016

Earlier this week Google Maps Engine was shut down. As a result, Google dropped three layers from Google Earth Pro, as they were dependent on Google Maps Engine. The dropped layers were “US Demographics”, “US Parcel Data” and “US Daily Traffic Counts”.

However, it now appears that another layer, the ‘Traffic’ layer, appears to have been dropped as well. It is not a layer that we use often so we are not certain when it was dropped, but we do think it was dropped recently. If any of our readers knows exactly when it was dropped please let us know in the comments. The layer used to show live traffic information for many large cities around the world and was distinct from the Google Earth Pro only layer “US Daily Traffic Counts”, which showed historical data for US traffic. The ‘Traffic’ layer was available in Google Earth as well as Google Earth Pro and has been there since 2007. If you want to see how it worked see this YouTube video.

So, was the Google Earth live traffic information working via Google Maps Engine?

Google Maps still has live traffic information, which shows as different colours on the route when you ask for directions as seen below, so it is evident that Google still has the information.

The post Google Earth Traffic layer dropped appeared first on Google Earth Blog.

Catégories: Sites Anglophones

NASA damage maps

mer 03-02-2016

We recently came across this interesting story about damage maps that NASA created after the Nepal earthquakes last year. We dug a little deeper and found this story on the NASA website, which includes a link to the damage maps viewable in Google Earth.

Grab the KML here. Be sure to also check out the layer labelled “NGA_All_Damage_Nepal_April_30th_2015_points“, which is not turned on by default. It shows the location of damage that has been confirmed. It appears to cover a slightly different area than the damage map and we did identify damage in the imagery on the right hand side of the damage map not covered by this layer.

The damage map is clearly not completely accurate, as it does not have a one to one correspondence with the actually identified damage. According to the NASA article it is based on change between satellite radar images between November 24, 2014 and April 29, 2015. As a result, a lot of changes not related to damage have been picked up. At the top left of the damage map a river really stands out. This is because river beds tend to change significantly over time.


The NASA damage map based on changes between radar images.


The map of directly identified damage overlaid on the NASA damage map.

The post NASA damage maps appeared first on Google Earth Blog.

Catégories: Sites Anglophones