Author: Peg Shippert
Close on the heels of a recent report by the Landsat Advisory Group concluding that the Landsat program has been wildly successful from the perspective of cost versus benefit, NASA recently announced that it and the US Geological Survey have begun work on the next Landsat platform, Landsat 9. Landsat 9 is expected to launch in 2023, and will carry two instruments: a visible through short wave infrared instrument, and a thermal instrument.
Jeffrey Masek, Landsat 9 Project Scientist at NASA's Goddard Space Flight Center observed, "We have recognized for the first time that we’re not just going to do one more, then stop, but that Landsat is actually a long-term monitoring activity, like the weather satellites, that should go on in perpetuity." This is excellent news for those of us with interests in observations of phenomena on the Earth's surface over time!
Landsat 5 TM image collected November 7, 1984 of Atchafalaya Bay at the mouths of the Wax Lake Outlet and the Atchafalaya River in the Mississippi delta plain. Image courtesy of NASA.
Landsat 8 OLI image collected October 25, 2014 of the same area, illustrating the growth of deltas in this area. Image courtesy of NASA. Image courtesy of NASA.
Categories: ENVI Blog | Imagery Speaks
A recent report by the Landsat Advisory Group of the National Geospatial Advisory Committee took a rigorous look at the value of Landsat-based information over the lifetime of the program. Their conclusion, not surprisingly, shows that Landsat has provided a spectacular return on public investment. The paper reports that the economic value of just one year of Landsat data, estimated to be $2.19 billion, far exceeds the total cost of building, launching and managing Landsat instruments.
The fact that Landsat data is most often used by non-commercial entities makes it difficult to estimate its economic value. Nevertheless, the committee was able to form an estimate based on cost savings from operational efficiency improvements, cost of alternatives to using Landsat data, and opportunity costs due to decision-making support provided by Landsat data.
The report asserts that people use Landsat because it is more efficient than any other technology at providing required information. It concludes that the savings realized due to the Landsat program will continue to accelerate as the program continues.
Landsat 8 OLI image of the Piqiang Fault in The northwestern Xinjiang province of China acquired on July 30, 2013. This beautiful image was the winner of NASA's 2015 Tournament Earth contest. (Courtesy of the NASA Earth Observatory)
I'm going to talk about someone else's work based on yet another body of work for a minute here, but bear with me because it's worth it. I just ran across an excellent article written by Brad Plumer for Vox based on NASA's Images of Change series. Images of Change is a set of before and after remotely sensed images from various places on the Earth. What I like about Plumer's article is that he includes a wide range of types of change, mostly focused on changes caused directly by human activity. He then describes each of them succinctly and clearly for the lay person. I also appreciate that he includes examples of both destructive (e.g., deforestation) and productive (e.g., reductions in air pollution) changes.
It's well worth a read. Check it out!
The Topaz Solar Farm in California, seen in 2011 (before the farm was built) and 2015. Image courtesty of NASA, Images of Change.
On Thursday, January 15 2015, suddenly one application of satellite imagery was all over the news. Not that CNN, ABCor any of the other big news outlets used the words "remote sensing",but that's what they were talking about. I first caught the story while listening to NPR in my car while running errands: Amnesty International had just released satellite images showing the impact of a horrific Boko Haram attack in northeast Nigeria.
The attack was the largest and most destructive perpetrated by Boko Haram so far, according to Amnesty International. And that's saying something. This is the group who carried out 115 attacks in 2011, killing 550 people. More recently, in April 2014, Boko Haram kidnapped 276 schoolgirls from Chibok, Borno, most of whom have still not been released. The recent attack involved the deaths of up to 2000 people and damage to an estimated 3700 structures.
Even with the satellite imagery, it's hard to tell exactly how much destruction was involved, due to the densely packed structures and tree canopies. But it is possible to see in the imagery that thousands of thatch roof structures and surrounding areas were completely destroyed by fires. The village of Doron Baga was "nearly wiped off the map" according to Amnesty International. CNN reported that this account matches eye witness statements, which describe desperate residents fleeing across Lake Chad.
Courtesy of Amnesty International. Copyright DigitalGlobe. Top: Image of Baga, North Eastern Nigeria, taken on January 2, 2015. Bottom: Image of Baga taken on January 7,2015, which shows many of the thatch roof structures have been razed. The dark color represents burned areas, while the red indicates healthy vegetation.
While our attention may have been diverted recently toward conflicts such as the war in Gaza and the actions of the Islamic State, the situation in Sudan has not been improving. Satellite imagery of hundreds of burned down homes attest to the growing crisis, which seems headed toward a replay of the ethnic cleansing by militias that began in 2003. This time, though, the Sudanese government seems to be more openly involved. Witnesses describe army officers, wearing state-issued uniforms, leading new militias in destroying villages and perpetrating other crimes in the area.
Recently George Clooney's Satellite Sentinel Project released a report describing the resurgence of Janjaweed militiamen, rebranded as Rapid Support Forces (RSF). While they may have a new name and official support of the government, reports indicate that they are no less "devils on horseback" than they were over a decade ago when the world first learned of their atrocities.
DigitalGlobe imagery has been an important tool for confirming and documenting the resurgence of violence in the area. For example, the Enough Project, a partner of the Satellite Sentinal Project, provide the following DigitalGlobe image, confirming significant damage to shelters adjacent to the African Union- United Nations Mission in Darfur (UNAMID) camp and a portion of Khor Abeche village in South Darfur, from fires set by RSF shortly before the image was collected on March 26, 2014. Imagery Courtesy of DigitalGlobe/Satellite Sentinel Project/ENOUGH Project.
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