Category: Remote Sensing
Another article in National Geographic’s Digital Places series touches on a topic of special interest: geospatial technologies and archaeology. The article discusses how users of Google Earth and other web mapping applications that feature aerial and satellite imagery are incerasingly being used to identify features of archaeological significance. As UNC-Chapel Hill archaeologisty Sccot Madry noted: “I’ve spent 25 years on and off bouncing around in low-level aircraft, searching old maps, looking at aerial photographs, and I found a handful of new archaeological sites. I found more sites on the first day of sitting down and doing a systematic survey on Google Earth than in those years of using the other techniques.”
The article also rightly points out that the use of remotely sensed images for identifying archaeological sites goes back to the beginning of aerial reconaissance during World War I when observers were able to see features such as ditches, circles and vegetation discolorations that weren’t visible from the ground, but until the new push for high-resolution imagery spurred by the web mapping boom, imagery was expensive and coverage was often spotty. It will be interesting to see how Google Earth and other applications will continue to impact archaeological survey and site identifications.
BBC News is back at it with another column on geospatial technologies. This time they looks at the impact of geospatial technologies over the last couple years in response to disasters and how it is used everyday. They look at aerial imagery, Pictometry and some of the privacy issues that have been raised by the general public now that they know that we have access to this type of information.
Honestly, we just don’t know. Apparently the basis of most of our belief in the lack of life on Mars might be bad data. The Viking Mars Mission from 30 years ago flew close enough to Mars to see if it could remotely detect signs of life. Apparently scientists have reproduced the technology the Viking mission used and tested it in remote regions of Earth. Their findings show that Viking wouldn’t have found life on Earth using the technology it employs in similar climate regions when clearly there is life on Earth in those regions. Does that mean there is life on Mars? Nope, not necessarily. All we can say is that the Viking Mission employed techniques that wouldn’t have found signs if there were any life on Mars. Hopefully the 2009 mission will help decide once and for all this age old question.
For those of you interested in using GIS and remote sensing in conservation-related activities, the Smithsonian National Zoological Park’s Conservation and Research Center is offering a week-long advanced GIS and remote sensing course from Sept. 11-15th at their facility in Virginia. They still have some slots left, and this would be a really good chance for people to learn about specific applications and issues related to Conservation GIS. The price is $1300, but does include lodging and breakfast.
At least that’s what researchers at the University of Texas at Austin are claiming. Their idea is to use some combination of GPS or RFID to track then cars enter into a congestion area. If vehicles enter during peak times, they would have to pay more in tolls than if they go through off-peak times. So drive into work at 8:00am? Pay $.25 per mile. Drive into work at 2:00am? It’s only $.10 per mile.
It’s an interesting idea, but I personally worry about a couple of things. Ultimately, what happens to all the data people collect about where I’m going when? What would keep outside parties from having access to that data? Finally, I’m not sure driving times are really responsive to market forces. I can’t easily choose an entry time more economical to my budget because, well, my employer says I have to be into work by 9:00am or get fired. If you triple the toll during that natural travel time, I’ll just have to pay triple. Unless my employer allows for complete hours flexibility, I’m not sure this is going to have much of a real impact (other than better roads from increased toll incomes).
Saw this one on HGTV’s I Want That: Tech Toys. The XB-39 Eagleye is a R/C plane with a built in digital camera allowing you to capture those high resolution obliques all on your own. Actually, I am just guessing it captures obliques based on the picture I saw…you may be able to capture nadir images. If you have one of these, or have played with one, let us know what you think.
One of the greatest things about all this aerial/satellite photography we have around is the historical analysis possibilities. The New York Times has used aerial photography to document the destruction going on in Beirut. The area of interest is the area around the Hezbollah headquarters in Beirut. The leftmost tab shows that area as it looked on July 12th, 2006. The middle button shows the aftereffects of 19 days of bombing. The damaged areas are utterly clear.
No matter what your stance on the Israeli/Lebanese conflict ongoing, the destruction is simply terrible. I think we, as geographers and remote sensing specialists, need to bring more imagery like this to the public eye to show the products of armed conflict.
English Heritage has released aerial images of Stone Henge taken from a ballon 100 years ago (August 1906). Head over and see the comparison with a modern aerial image. Just because things are digital doesn’t mean they are new.
Recently, we received several books from ESRI Press for reference and review, and first up is Remote Sensing for GIS Managers (2005) edited by Stan Aronoff. Aronoff and his co-authors have provided a comprehensive overview of remote sensing, ranging from the history of remote sensing to types of sensors offering an in-depth and thorough presentation of Remote Sensing.
The title is somewhat misleading since this book would work nicely as a text in an undergraduate remote sensing class, offering general information on aerial and satellite based remote sensing. There is, in fact, very little GIS oriented material aside from a few case studies in one of the later chapters. The text is divided into roughly five sections: Chapters 1-4 offer a general introduction, Chapters 5-9 review different types of sensors, Chapters 10-11 discuss image interpretation, while Chapters 12-13 cover examples of applications and how Remote Sensing fits in organizations. The last section is made up of three appendices that offer very detailed information on georeferencing imagery, individual sensors, and a list of resources.
Each of the sections is well organized, offering information that is relevant and descriptive enough to convey the technical ideas to a broad audience. As should be expected from any book that revolves around imagery, there are several full color reference figures that support the text. These figures represent not only raw data, but data capture and image analysis techniques. Perhaps the most useful portion of the book is also the portion that will eventually date it, the overview of satellites and their relative capabilities. This portion of the text is the most relevant to the title, providing a wide set of information on platform capabilities which is important to GIS managers who are looking for the best, most cost effective imagery or sensor data for a given problem or project. In the end this book is not going to be touted as a landmark in Remote Sensing, but it is a solid reference work.
Overall, this is a strong remote sensing text which is very affordable in comparison to most textbooks at $69.99US. Be wary of this text if you are looking for a quick and dirty introduction to Remote Sensing, which is what I would expect most Ã¢â‚¬ËœGIS ManagersÃ¢â‚¬â„¢ would want. Instead, at nearly 500 pages this text would be a good addition to a reference library if you do not already have an introduction to Remote Sensing style textbook.
If you’re like me, when you go to plan your summer vacation, weird questions like, “Is there a major earthquake fault or active volcano in the area?” will eventually come up. Now you don’t have to worry about those pesky active volcanoes in your holiday planning! The site features a google mashup with the Smithsonian and USGS Weekly Volcano Activity Report, so you know you’re always up-to-date with the volcanic activity in the area. Clicking on the volcano point brings up a handy, dandy popup featuring current activity, background, some general information, and the more complete entry into the greater database. The general tab will let you zoom directly to the volcano for a better look.