Tuesday, February 19, 2013
Randolph Wynne, professor of forest remote sensing at Virginia Tech’s College of Natural Resources and Environment, flew to California last week to witness his hard work, literally, take off.
For the past six years, Wynne has been working with other scientists from around the country on the Landsat Science Team, preparing for the launch of NASA’s newest land-monitoring satellite, Landsat 8.
The “Landsat 8,” previously known as the Landsat Data Continuity Mission, was launched from Vandenberg Air Force Base in California at 10:02 a.m. PST on Feb. 11.
James Campbell, professor of geography and member of VirginiaView, a consortium of universities or organizations that are active in remote sensing and advocates of the Landsat program, also attended the launch.
“It was in many ways spectacular and a very exciting and moving event and particularly to be there with so many other participants in the program because they literally came from all over the world to be there,” Campbell said.
Along with remote sensing scientists, there were numerous other groups in attendance at the launch including engineers, designers and scientists in water resources and forest resources.
“It was a gathering of like-minded scientists,” Campbell said. “That was another reason that it was a very interesting place to be, because it’s not very often that all of these groups are in one place at the same time.”
Purpose of the Landsat
This satellite is seventh in a series of land-monitoring satellites developed by NASA for the U.S. Geological Survey, a scientific agency of the government studying landscape, natural resources and natural hazards.
The Landsat satellites have been in operation for the past 40 years, collecting images of Earth’s surface from space.
“Probably one of the most important things about Landsat is the fact that it’s a 40-year continuous record of the earth surface at a scale at which humans manage it and that’s, from my perspective, extraordinarily important,” Wynne said.
The Landsat missions have provided useful images for programs such as Google Earth and have allowed scientists to monitor the health of our environment from a bird’s-eye view.
“On the Forest Management side, we routinely have people that will use data from Landsat to determine whether a forest might need fertilization, for example, (if) it’s nutrient limited,” Wynne said.
The commonwealth of Virginia also uses data from Landsat missions to double-check that landowners keep a certain amount of forest around their streams to ensure water quality maintenance.
“Because of the longevity of the data stream, it’s not just science that benefits,” Wynne said. “I think it is important to realize that it has become an anticipated portion of our national infrastructure in the same way that weather satellites are… and we have a number of important sectors that really truly rely upon this data.”
About the satellite
The images provided by Landsat 8 will cover almost the entire surface of the earth, excluding small areas of the Polar Regions as it will orbit around the earth at approximately 88 degrees north to 88 degrees south.
The official design life of Landsat 8 is five years; however, both Wynne and Loveland expect it to be operational for a minimum of 10 years.
Outlasting design life is not unusual for Landsat satellites. Landsat 5, launched in 1984, was just recognized by the Guinness Book of World Records as the Longest Operating Earth Observation Satellite after nearly 29 years of service.
In addition to structural changes, the Landsat 8 design also includes an additional two wavelength bands, which are meant to increase quality of images used to monitor water quality and high-level cirrus clouds.
According to Wynne, the launch of the Landsat 8 was about $100 million and upkeep of the satellite will cost about $15 million per year.
The Landsat Team
The Landsat Science Team is a joint effort of NASA and the USGS.
While NASA works to build and launch the satellite, USGS is providing the ground data processing systems which will be located at the USGS Earth Resources Observation and Science center.
Following the launch the Landsat Science Team will be developing the plans for evaluating the imagery when it becomes available in May.
“One of the things the team has a responsibility for is to evaluate the data quality and the new data characteristics … to make sure that they’re suitable for solving the problems that the mission was designed to address,” Loveland said. “Right now, we’re in planning mode as we get ready to start working with the images as soon as they become available.”
Once the satellite is fully operational, after on-orbit verification by NASA, the Landsat Science Team’s job will change as the USGS will lead post-launch calibration activities, satellite operations, data product generation and data archiving.
“Now that we actually have LDCM, (our job) shifts into demonstrating the actual benefits of the [satellite] and addressing the requirements of the next Landsat, which someday may be authorized,” Loveland said.
The big picture
“The overall goal of the mission is to monitor the changes in the land surface at a scale that allows us to distinguish between changes caused by human activity versus changes that are the result of natural forces,” Loveland said.
The Landsat satellites offer more than just pictures. Data collected by the satellites are particularly useful to scientists studying climate change.
“(It will serve) a wide range of operational purposes… as we continue to try to understand what’s causing climate variability and change,” Loveland said. “Landsat provides a lot of the objective information on the condition of the land surface that may either be affected by climate change or is contributing to the changes in climate.”
While data from the satellites is useful for scientists, the data is also useful for farmers, city planners, as well as the average person.
“I would say one of the most important things is it helps humans understand and manage their environment,” Campbell said. “So we can think of the big picture as sustainability and understanding how we use the earth for agriculture, its water resources, urban areas, forests, range land.”
Both Wynne and Loveland plan to continue working jointly with NASA and to contribute to a Landsat 9 project in the future.
“As scientists, we like to think that what we do is important and what we’re finding has policy relevance,” Wynne said. “But in the end, if there’s a user community out there that finds the data fruitful, that’s really, in the end, what we we’re striving for all along.”