My Google Map Blog

Archive for June, 2016


The best of Google Earth for June 2016

by Timothy Whitehead on Jun.30, 2016, under 3D Models, Argentina, Australia, Brazil, California, Denmark, England, Germany, Google Earth News, Google Earth Tips, Google Sky, Google maps, Hawaii, Indonesia, Ireland, Italy, Japan, Kenya, Mexico, Natural Landmarks, Netherlands, Sightseeing, Street Views, USA

The biggest news this month is that Google Earth got a makeover, with Google updating the global mosaic shown when zoomed out. Overall, we like it a lot, but nothing is perfect, so we had a look at some of the minor issues it still has.

Google Earth Imagery Update: The Dallas, Texas Tornados There were several imagery updates in the month and we had a look at some of the interesting sights to be found in the imagery, including:

Google Earth Imagery Update: Strange image in the SaharaWe also discovered an image in the Sahara Desert from Google’s Terra Bella. The image has since been removed. Presumably Google were just testing something. It would be nice if they do decide to use Terra Bella imagery to fill in the gaps in Google Earth’s high resolution imagery.
 
 

Spectral Transformer for Sentinel-2 ImageryWe had a look at a new tool by GeoSage called Spectral Transformer for Sentinel-2 Imagery which, as the name suggests, is for processing imagery from the Sentinel program.
 
 
 

What does it take to process 3D imagery?We noted that Google had released some imagery of Rio de Janeiro, Brazil, that was captured in 2013 and we talked about the reasons why it sometimes takes Google so long to release 3D imagery.
 
 
 

Satellite image archaeologyWe had a look at an archaeological find in Petra, Jordan, that was found by Dr. Sarah Parcak with the aid of satellite imagery.
 
 
 
 

The rock near Deception Island that looks like a KrakenWe had a look at a story about a Kraken being spotted in Google Earth imagery – which turned out to be a rock.
 
 
 
 

Making desktop backgrounds with Google EarthWe had a look at how to make desktop backgrounds with Google Earth imagery (Google Earth Pro makes it easy).
 
 
 
 

Historical imagery and UkraineWe came across a story on Bellingcat that mentioned that Google is continuing to update historical imagery in Ukraine, despite it being essentially censored since July 2015. We discussed the issue as well as having a look at some of the locations relevant to the Bellingcat story.
 

Sun-synchronous orbitWe had a look at Sun-synchronous orbit, the orbit configuration used by most imaging satellites.
 
 
 
 

Advanced Historical Imagery Tour Maker with the Google Earth APIWe provided a Google Earth API based tool for making historical imagery animations and also gave some tips for making good animations.
 
 
 

Rio de Janeiro with Google EarthWe had a look around Rio de Janeiro and the developments in preparation for the upcoming Olympics. We also had a look at an oil refinery there and animated the oil tanks showing the floating roofs rising and falling over time, depending on oil stocks.

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

Comments Off :, more...


The Google Earth new global mosaic: a deeper look

by Timothy Whitehead on Jun.29, 2016, under 3D Models, Argentina, Australia, Brazil, California, Denmark, England, Germany, Google Earth News, Google Earth Tips, Google Sky, Google maps, Hawaii, Indonesia, Ireland, Italy, Japan, Kenya, Mexico, Natural Landmarks, Netherlands, Sightseeing, Street Views, USA

Google recently refreshed Google Earth’s global mosaic with newer, sharper imagery. So far, we like it very much and think it is definitely an improvement. However, we will have a look around and see if we can find any flaws or interesting aspects to the new imagery.

Landsat 7 stripes

We already pointed out yesterday that although Landsat 8 imagery was used in the new mosaic, it is not entirely free of Landsat 7 imagery with its characteristic stripes. They typically show up in hard to photograph places, such as those that have near year round snow cover or cloud cover, but we think we even saw some in the Sahara.

Coverage

There are a few locations where non-Landsat imagery has been included in the mosaic. This includes a number of islands, such as Svalbard and the islands in the South China Sea.
Below we can see a particularly noticeable strip across Smith Island, which is part of the Andaman and Nicobar Islands in the Indian Ocean. The image is actually a DigitalGlobe image from 2011 which disappears as you zoom in.

We believe the reason for this is that there simply aren’t any good quality, snow-free and cloud-free Landsat images of the locations in question. Islands, it would appear, are cloud magnets.

Colouring

Overall, the contrast in the imagery is noticeably higher and features you may have never noticed before stand out. Lakes generally seem to be greener or browner than before.

Oceans

It is important to note that the ocean floors are actually a different data set and have not, as far as we know, been updated at this time. However, they did receive a significant update in January this year. We have come across some oddities in the margin between land and sea. For example, along the coast of Vietnam there is a thin border of brown where the Landsat mosaic ends, but between that and the sea floor data is some other imagery which includes some clouds.

We saw this same effect in a number of other locations around the world.

We also found that if you zoom in on Chandler Sound, which is part of the Mississippi delta in the Gulf of Mexico, Google Earth shows this strange pattern:


We are not sure if this has anything to do with the global mosaic update.

Dating the imagery

The imagery is a mosaic collected from parts of images from the Landsat archive going back many years, so it is impossible to put a date on the whole mosaic. However, there are specific places where it is possible to determine the approximate date of the imagery used. The best locations to do this would be large lakes or inland seas that are shrinking or growing over time. We haven’t yet done this for any such lakes, but we did check the Nansen Ice-shelf in Antarctica and determined that the imagery there has not been changed from the previous mosaic. The imagery is from 2003 as we determined when watching the ice sheet crack. We also checked Bento Rodrigues in Brazil and are fairly sure that the imagery is from before the disaster that took place there in December last year

Resolution

Landsat imagery has a resolution of only about 30m per pixel and we suggested yesterday that Google consider using Sentinel imagery, which is higher resolution. However, after some consideration we have realised that for the global mosaic, the important factors are consistent colouring and good global coverage. As you zoom in, Google Earth transitions to higher resolution imagery where available so greater resolution of the global mosaic is not necessary. It is, however, the case that there are some parts of the world where no higher resolution imagery exists and the Landsat imagery is used even when you zoom in and only for these locations does Google need to seek alternative sources. For much of the globe they have already used medium resolution imagery from Spot Image. For more on what image sets are used where, see our series on Google Maps API Maximum Zoom.

To see the locations featured in this post in Google Earth download this KML file.

The post The Google Earth new global mosaic: a deeper look appeared first on Google Earth Blog.

Comments Off :, , more...


Google Earth gets a makeover!

by Timothy Whitehead on Jun.28, 2016, under 3D Models, Argentina, Australia, Brazil, California, Denmark, England, Germany, Google Earth News, Google Earth Tips, Google Sky, Google maps, Hawaii, Indonesia, Ireland, Italy, Japan, Kenya, Mexico, Natural Landmarks, Netherlands, Sightseeing, Street Views, USA

Google Earth has just had a makeover. Google has refreshed the global mosaic imagery that you see when zoomed out with newer, better quality imagery. When you zoom in, Google Earth transitions to higher resolution imagery where available, but in places where it is not available, the global mosaic remains. When Google Earth was first released it looked like a patchwork of imagery – essentially the same as it does today when you switch to ‘historical imagery’. Then, in 2012, they released ‘Pretty Earth’ a global mosaic derived from Landsat data which made Google Earth look a lot better. As far as we know, this is the first refresh to the global mosaic since then. The first mosaic was produced using Landsat 7 data. Landsat 7 has faulty instrumentation, which resulted in stripes in the imagery at some locations.

Read more about the new global mosaic on Google’s Lat Long Blog.

Landsat 8 was launched in 2013 and the new mosaic incorporates imagery it has gathered. However, we believe we can still detect, in places, the characteristic stripes of Landsat 7 data, suggesting that the mosaic is not exclusively from Landsat 8.


A location in Venezuela. The squares are roads. The broader, nearly horizontal stripes in the vegetation are almost certainly due to a Landsat 7 image being used.

Also see the Vatnajökull Glacier on Iceland for another location where the Landsat stripes are visible.

Overall, the contrast is higher in the new mosaic and in parts of the US you can see a distinct checkerboard pattern:


The checkerboard pattern is real, being a consequence of the Jefferson Grid.

The mosaic is created by carefully selecting cloud-free and snow-free sections of imagery from the catalogue of Landsat imagery. The resulting, largely cloud-free and snow-free view of the world is actually quite unrealistic. In some cases, such as some mountain ranges and the poles, it has proved impossible to find completely cloud-free, snow-free imagery.


Some clouds are visible in the Falklands.


The northern coast of Greenland hasn’t fared too well with the update, but that is because this is outside of Landsat’s coverage.

Overall, we think the new mosaic is a significant improvement, but without the old one to compare it with, it is difficult to make an accurate comparison.

As far as we know, Sentinel imagery is freely available under similar conditions to the Landsat data. In addition, it is higher resolution than Landsat data. We wonder whether Google has looked into incorporating Sentinel data in the global mosaic.

To find the locations mentioned in this post in Google Earth download this KML file.

The post Google Earth gets a makeover! appeared first on Google Earth Blog.

Comments Off :, more...


Historical imagery and Ukraine

by Timothy Whitehead on Jun.27, 2016, under 3D Models, Argentina, Australia, Brazil, California, Denmark, England, Germany, Google Earth News, Google Earth Tips, Google Sky, Google maps, Hawaii, Indonesia, Ireland, Italy, Japan, Kenya, Mexico, Natural Landmarks, Netherlands, Sightseeing, Street Views, USA

As we have mentioned in the past Google Earth does not have any imagery of Ukraine since June 2015, which puts it on the list of censored countries that includes Afghanistan, Iraq and Syria. However, a recent report on the citizen journalism site Bellingcat states that Google recently added some historical imagery from July 17, 2014, the day of the downing of Flight MH17. In fact they even know the exact time the image was captured: 11:08am (local time). Google Earth does not show the time that imagery was captured but the reporters at Bellingcat know exactly which DigitalGlobe image was used, and DigitalGlobe does know the exact time that a given image was captured.

If they are correct that the image was only recently added to Google Earth, this would suggest that whatever mechanism has been used to censor the country does not extend to historical imagery from 2014. Also of note is the fact that the Ukraine received Street View in October 2015 although it doesn’t appear to have been updated since then. The most recent Street View we could find was dated July 2015. There is no Street View in most of the eastern parts of the country and Crimea. There is some Street View of Donetsk, but that is dated 2011.

As you can see below, the new sighting of the BUK that is believed to have been used to shoot down Flight MH17 isn’t very significant, as it just adds an extra point to the fairly well documented route of the vehicle that day as identified by Bellingcat from various sources.


The green pin shows the new sighting.

To see the above locations in Google Earth download this KML file Note that the truck carrying the BUK can not be seen in the imagery in most of the locations marked, but rather it is known to have been at those locations at those times because of various photos / videos of it. See this Bellingcat report for the sources of the locations.

At one point Russia released a fake photo supposedly showing a fighter jet shooting down flight MH17.

The post Historical imagery and Ukraine appeared first on Google Earth Blog.

Comments Off :, , more...



Looking for something?

Use the form below to search the site:

Still not finding what you're looking for? Drop a comment on a post or contact us so we can take care of it!

Visit our friends!

A few highly recommended friends...