My Google Map Blog

We recently came across the YouTube video below about Google Earth’s 3D imagery. It gives some insight into how it is gathered and we also get to see some of the faces behind Google Earth, such as Google Earth Product Manager Gopal Shah.

Apparently the aircraft used to gather the 3D imagery use five cameras, one facing down then four others pointed in different directions. The ‘stereo’ imagery is not actually achieved by two cameras taking photos from different angles, but rather each single camera taking multiple photos as the aircraft is moving, effectively achieving a stereo effect. Previous analysis we have done (1 2 ) suggests that each camera captures four images in quick succession to get the ‘stereo’ effect for any given location and then imagery from multiple passes from different sides of the location are combined to create the final 3D.

Also interesting is that Gopal seems to imply that cars are manually removed from the imagery rather than via an automated process. Not mentioned in the video is the fact that Google pays special attention to some structures like bridges, harbour cranes and certain intricate buildings, using more manual methods. We believe the manual part of the process is the main reason 3D imagery often takes a long time between when the images were captured and when they are published in Google Earth.

It must also be pointed out that Google is continually improving the process and the latest releases of 3D imagery are significantly better quality than the oldest 3D imagery.

The post Some insight into Google Earth’s 3D imagery appeared first on Google Earth Blog.

Google has recently released a new batch of 3D imagery. The last major release was in early February. Thank you to all the GEB readers that contribute by finding new areas and drawing outlines. Below is a chart showing the areas in square kilometres released over time. It does not include all of the recent March batch as only some of the outlines have been drawn so far.

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

Keep in mind that the above areas do not include updated regions. These can be difficult to identify so we do not track them. The general trend is a decline in new area covered. We believe that this is partly a reflection of the fact that most of the large population centres in countries where Google is releasing 3D imagery have already been covered. It is likely that Google still releases approximately the same area of 3D imagery each month, but much of it is now updates, not new areas.

The largest single area at 19,500 square kilometres is now the New York City region. It includes parts of five different states and is more than double the area of the second largest region (San Francisco at 7,800 sq km).

Thank you to GEB reader Ryan for pointing us to Trump’s aircraft captured in 3D in one of the latest 3D releases in Florida:

It is parked not far from Mar-a-Largo, owned by Trump and which he now refers to as his Southern White House. We were unable to date the 3D imagery as there is not much aerial imagery in that location to compare it with. Trump now uses Airforce One, which we have also looked at in 3D. Find it in Google Earth with this KML file.

The post Google Earth 3D imagery progress appeared first on Google Earth Blog.

If you ever get bored of Google Earth’s 3D imagery, then a fun thing to try is changing the ‘terrain exaggeration’. It is a setting found in Tools->Options->3D View->Terrain (PC) or Google Earth->Preferences->3D View->Terrain (Mac). This setting stretches or compresses the terrain vertically, and it also applies to Google Earth’s 3D imagery. It can give a whole new look to familiar sights.

Table Mountain, Cape Town, South Africa. No terrain exaggeration.

Table Mountain, Cape Town, South Africa. Terrain exaggeration: 3.

Cape Town, South Africa. No terrain exaggeration.

Cape Town, South Africa. Terrain exaggeration: 0.3.

New York, United States. No terrain exaggeration.

New York, United States. Terrain exaggeration: 3.

Remember to set the terrain exaggeration back to 1 once you are done.

The post Fun with Google Earth’s terrain exaggeration appeared first on Google Earth Blog.

While exploring Google Earth’s 3D imagery, you will probably have noticed that even in the busiest cities, people are largely absent. This is because of the way the 3D imagery is captured. Based on previous analysis, the 3D imagery is captured by taking four images in rapid succession from an aircraft and then another four later on on a separate pass. It is also possible that more than two passes are combined, and we have even come across one case where it appears that Google combined imagery from completely different flights months apart. The overall result is that anything that is moving cannot be properly imaged in 3D. Over time, Google has got better at removing moving vehicles from the imagery so the streets appear almost empty, and we never seem to see pedestrians at all.

However, while exploring the 3D imagery in Dublin, Ireland we came across some people in the parks there. It mostly includes people lying down or sitting and they evidently stayed in the same place long enough that the 3D imagery process was able to capture them. However, as far as we can tell, none of them actually got proper 3D models. That is probably due to a combination of factors. The resolution of the 3D mesh is not really high enough to model a human. Also if the people were moving around even slightly, although they will still be visible in the image data, the algorithms used to generate the 3D from stereo images would fail.

Dubh Linn Gardens, Dublin, Ireland

We also managed to find some people on a beach in France. In this case a few of the beach umbrellas did get detected by the 3D generation algorithms. The waves on the shore seem to have caused problems for the algorithms as there are blobs of floating sand all along the shoreline.

Beach in Marseille, France

Beach in Marseille, France

Have any of our readers come across a place where a person was standing still long enough to get captured in 3D? Let us know in the comments.

The post People in Google Earth’s 3D imagery appeared first on Google Earth Blog.

Thank you to GEB reader Jacob for bringing to our attention an interesting effect in Google Earth’s 3D imagery. In Kingston, Ontario, Canada, there is a building in the 3D imagery that seems to be a combination of imagery from when it was still under construction and imagery from after its completion. The result is quite interesting and worth exploring in Google Earth. Find it in Google Earth with this KML file. Be sure to turn on the 3D buildings layer.

The 3D imagery was only recently added to Google Earth (first reported by GEB readers on January 3rd, 2017) but, based on historical imagery the building was constructed between May 2014, when there is no building visible, and September 2015 when it is mostly finished. So at least some of the imagery used to create the 3D is several years old.

We have previously noted a case where a building could be seen in different stages of construction depending on zoom level and an instance where whole buildings were missing from the 3D imagery.

The post Two stages of construction in Google Earth 3D imagery appeared first on Google Earth Blog.

Over the course of 2016, Google Earth received about 90,000 square kilometres of new 3D imagery (about the area of Portugal). This represents a significant slowdown in new area covered:

New area of 3D imagery by year in square kilometres.

New area of 3D imagery by month in square kilometres.

However, a lot of previously existing areas received updates, either with freshly captured imagery or reprocessed imagery, but such updates are impossible to track in terms of area.

Three new countries received imagery this year, Tunisia, Malaysia, and most recently Slovenia.

As always, a big thank you to all the GEB readers who contribute to our KML map of 3D areas by alerting us to new areas and/or drawing outlines. If you submit outlines please be sure to follow the guidelines.

Ljubljana, Slovenia.

The post Google Earth 3D imagery progress for 2016 appeared first on Google Earth Blog.

Over the course of 2016, Google Earth received about 90,000 square kilometres of new 3D imagery (about the area of Portugal). This represents a significant slowdown in new area covered:

New area of 3D imagery by year in square kilometres.

New area of 3D imagery by month in square kilometres.

However, a lot of previously existing areas received updates, either with freshly captured imagery or reprocessed imagery, but such updates are impossible to track in terms of area.

Three new countries received imagery this year, Tunisia, Malaysia, and most recently Slovenia.

As always, a big thank you to all the GEB readers who contribute to our KML map of 3D areas by alerting us to new areas and/or drawing outlines. If you submit outlines please be sure to follow the guidelines.

Ljubljana, Slovenia.

The post Google Earth 3D imagery progress for 2016 appeared first on Google Earth Blog.

Google recently released 3D imagery for Mount Fuji in Japan. However, we discovered that there are a number of squares of the imagery that appear only in low resolution. We have come across this problem before and interestingly another location with a similar problem is Mount Vesuvius in Italy.

Mount Fuji, Japan.

Mount Vesuvius, Italy.

A third volcano, Mount Saint Helens in Washington State, USA, also has 3D imagery, but does not have any problems with it:

Mount Saint Helens, Washington State, USA.

The problem with squares of blurred 3D is not restricted to volcanoes. We know of a number of other places around the world where the same issue occurs. For the ones we know about, download this KML file. If our readers know of any others, please let us know in the comments.

Thank you to GEB reader Samppa for letting us know about this one in Rio de Janeiro, Brazil.

One location that had a similar problem a couple of years ago was Oslo, Norway. Oddly enough, that seemed to get fixed when the Google Earth client was updated.

Another type of 3D imagery anomaly is this one near Austin, Texas:

The above volcanoes are not the only areas where Google has captured 3D imagery outside urban areas. For a number of US parks see this post and for a number of other non-urban areas see this post.

The post 3D volcanoes and 3D data corruption appeared first on Google Earth Blog.

In April this year, the city of Kumamoto, Japan, suffered a series of large earthquakes. Google managed to capture aerial imagery of the city essentially during the event, after the first major event but before the largest shock and then captured another set of imagery from after the event. We had a look at what damage could be seen in the imagery, including a large number of landslides, collapsed buildings and a derailed train. From the overhead imagery it wasn’t easy to see the extent of the damage to buildings, even though we knew, based on ground level imagery, that there was severe damage in some locations. Now Google has updated the 3D imagery for part of Kumamoto with imagery captured after the event, and the extent of the damage to buildings is much clearer, especially because the roofs have been patched with light blue tarpaulin that is highly visible.

The suburb of Mashiki was the worst hit, and many houses are damaged beyond repair.

A historical building known as Janes’ Residence was completely destroyed. The rubble has been covered in the light blue tarpaulins

The Janes’ Residence was the first western-style house built in Kumamoto dating from 1871. It used to be in the grounds of Kumamoto Castle, but has been moved a number of times. Read more about it here.

Kumamoto Castle was badly damaged by the earthquake.

We have also created a Google Earth tour of the area showing all the light blue roofs, which you can view in Google Earth with this KML file or see in the YouTube video below.

The post Post-earthquake Kumamoto in Google Earth 3D appeared first on Google Earth Blog.

Malaysia and Tunisia have recently received their first 3D imagery. Tunis and Sfax in Tunisia and Sungai Petani in Malaysia.

The interesting upside down triangle architecture of the Hôtel du Lac, Tunis.

Constructions sites are the easiest way to work out the date of 3D imagery. This construction site in Sungai Petani, Malaysia, tells us the 3D imagery was captured since the most recent satellite image from January 2016.

As we have previously mentioned Google appears to be slowing down in terms of new area covered by 3D. However, they are doing a significant amount of updates of existing areas.

Note that a few of the most recent finds for this month are not included in the above chart, as we have not yet finished drawing the outlines.

To see the full coverage of 3D imagery in Google Earth and find out what other recent additions there are, download this KML file.

York Minster in York, England.

The post Malaysia and Tunisia get 3D appeared first on Google Earth Blog.