Tag: Google Earth

Location, location, location

I have long been intrigued by location based data. Location provides a context that allows one to better understand data. Often, we know something more when we identify a location and this extra information allows better understanding of an event that happened at that location.

Here is an example that may help explain this abstraction. A specific attribute of the camera on most cell phones is the geolocation capability. Exactly where was that picture taken? The capability is now usually there, but the default seems to be to have this capability turned off. I suppose this is because there is some concern regarding privacy. We are willing to share photos, but seem concerned that we would also share the location where the photo was taken (e.g., this was taken in my home and this is where my home is located). I think the location data can have many useful educational applications so learning to turn the recording and sharing of the location data associated with images on and off could be an important skill to have.

Anyway, I noticed a blog post that explained how to map a collection (set) of images stored in Flickr to Google Earth. We recently returned from a three-week adventure in Russia and we took a large number of pictures while we were there. One of the problems I always have with such picture collections is that I lose the context over time if I do not do something with the pictures immediately. I like to explain this problem based on the experience that “a month later, one mountain looks a lot like another”. With the Russia adventure, this problem might be explained as “after a month, one statue or palace looks like another”. I tend to take pictures on trips with a reasonably high quality camera, but I have also learned to take some of the same pictures with my phone (turn off your data plan). The geotags captured by the cell phone when cell phone images are mixed with the digital camera images by date and time allows some context (location) to jog my memory for events. The technique for mapping to Google Earth just provides an interesting way to display your pictures AND to view pictures taken by others at the same location.

The blog post provided by Adam Franco explains the method which amounts to loading the images of interest into a Flickr set and then executing a script that generates a KML file on the address for this set. The KML file is than loaded into Google Earth to display the location of specific pictures.

russiaimagemap

 

You can kind of see how this works in the image above. The KML file links to the pictures in Flickr and shows the location on the map. Other images are represented on the map and these also can be viewed.

If you would like to explore our iPhone collection (actually I did not have the settings on my new Samsung S4 set to record geotag data, but Cindy did have the setting turned on), I have placed the KML file in the public folder of my DropBox Account. Download this file and open with Google Earth.

By accident, I included a photo taken in Wisconsin with the images taken in Russia. Watching Google Earth move to accommodate the different locations is interesting. The detail in the maps is also interesting and the accuracy of the image location is impressive. Creating collections that are geotagged offers some interesting possibilities.

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Google Earth

Yesterday I read a post on LifeHacker describing the newest release of Google Earth. A video offered within this site describes new features available in version 5.0. You can locate the download at the Google Earth site. A new feature I found intriguing allows the investigation of changes over time.

Rather than duplicate the examples discussed, I wanted to test the tool using a situation I have experienced. I happen to be watching a local outdoor show a few days ago. The guest was a resort owner from Devils Lake, North Dakota, who was talking about the interesting history of the lake. He described the tremendous changes in the level of the lake that have occurred over time and told his own personal story as a short term example. He described working at the Creel Bay boat launch as a youth. At the time it was one of the few locations on the lake where you could rent a boat or purchase bait. He described that the facility was now gone as the location was submerged in the rising waters. This caught by attention. When I first came to North Dakota 30+ years ago a few colleagues from the department and I would go fishing from the Creel Bay marina in the summer. My brother later moved to Devils Lake and lived near this location. He left the area and I stopped taking trips there, but I knew the story of the rising waters.

I decided to examine this phenomena using Google Earth. My strategy was simply to locate Devils Lake in Google Earth and capture a picture of the area. Without changing the area shown, I using the “clock” tool to change the date and attempted to capture the same area of the map. recentdl

Recent image (2005)

olderdl

Older image (1997)

I found my assumptions regarding how easy this would be were somewhat naive. It turns out you cannot find images for any given date. The most recent I could locate for Devils Lake were from 2005. The images were generated by different organizations. I also assume that the time of year the images were taken would influence what was observed. In other words, precise control was not possible. However, if you look carefully, you can detect change. I have identified a common area in a small section of map that shows how a greater area of land is submerged in the more recent image. Science is like this – it is difficult to control all variables and demonstrations are often more difficult to produce than one expects. This is a very interesting tool and certainly available for personal experimentation.

More information describing Devils Lake is available online.

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