4.
Measuring Area in Digital Images
2009 June 30. Most
complete Earth map published. BBC News. Excerpt:
The most complete terrain map of the Earth's
surface has been published.
The data, comprising 1.3 million images, come
from a collaboration between the US space agency
Nasa and the Japanese trade ministry.
The images were taken by Japan's Advanced Spaceborne
Thermal Emission and Reflection Radiometer (Aster)
aboard the Terra satellite.
The resulting Global
Digital Elevation Map covers
99% of the Earth's surface, and will be free
to download and use.
..."This is the most complete, consistent
global digital elevation data yet made available
to the world," said Woody Turner, Nasa
programme scientist on the Aster mission.
...Previously, the most complete such topographic
map was Nasa's Shuttle Radar Topography Mission,
covering 80% of the Earth's surface. However,
the mission's results were less accurate in
steep terrain and in some deserts.
Nasa is now working to combine those data with
the new Aster observations to further improve
on the global map....
Earth
Exploration Toolbook -- provides step-by-step
instructions for using Earth science datasets
and software tools in educational settings.
Each chapter of the EET walks users through
an example-a case study in which the user
accesses data and uses analysis tools to explore
issues or concepts in Earth system science.
In each chapter, users produce and analyze
maps, graphs, images, or other data products.
Chesapeake
Bay from Space The site contains a wide
variety of remote sensing data and tools designed
to introduce decision makers to the use and
interpretation of Landsat 7 imagery, with
a primary focus on imagery used to measure
the extent of impervious surfaces in the Chesapeake
Bay and Maryland Coastal Bays Watersheds.
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|
Chapters
- Three
Color Light
- Pixels
and Colors
- Measuring
Length in Digital Images
- Measuring
Area in Digital Images
- Exploring
and Measuring Light
- Spectral
Analysis
- Temporal
Analysis of Satellite Images
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6.
Spectral Analysis
2009 May 28. RELEASE:
09-124 NASA SATELLITE DETECTS RED GLOW TO
MAP GLOBAL OCEAN PLANT HEALTH. Excerpt:
WASHINGTON -- Researchers have conducted the
first global analysis of the health and productivity
of ocean plants using a unique signal detected
by NASA's Aqua satellite. Ocean scientists can
now remotely measure the amount of fluorescent
red light emitted by phytoplankton and assess
how efficiently these microscopic plants turn
sunlight and nutrients into food through photosynthesis.
Researchers also can study how changes in the
global environment alter these processes at
the center of the ocean food web.
...Phytoplankton account for half of all photosynthetic
activity on Earth and play a key role in the
balance of carbon dioxide in the atmosphere.
The health of these marine plants affects the
amount of carbon dioxide the ocean can absorb
from the atmosphere and how the ocean responds
to a changing climate.
"This is the first direct measurement of
the health of the phytoplankton in the ocean," said
Michael Behrenfeld, a biologist who specializes
in marine plants at Oregon State University. "We
have an important new tool for observing changes
in phytoplankton every week, all over the planet."
...Using the Moderate Resolution Imaging Spectroradiometer
(MODIS) on NASA's Aqua satellite, scientists
have now observed "red-light fluorescence" over
the open ocean. MODIS is the first instrument
to observe this signal on a global scale.
...Scientists previously used satellite sensors
to track the amount of plant life in the ocean
by measuring the amount and distribution of
chlorophyll. "Chlorophyll gives us a picture
of how much phytoplankton is present," said
co-author Scott Doney, a marine chemist from
the Woods Hole Oceanographic Institution in
Woods Hole, Mass. "Fluorescence provides
insight into how well they are functioning in
the ecosystem."
With this new measurement, the scientists discovered
large areas of the Indian Ocean where phytoplankton
were under stress from iron deficiency. They
were surprised to see large portions of the
ocean "light up" seasonally as phytoplankton
responded to a lack of iron in their diet. The
amount of fluorescence increases when phytoplankton
have too little iron, a nutrient in seawater.
Iron reaches the sea surface on winds blowing
dust from deserts and other arid areas, and
from upwelling currents. ...
2005 Feb. TERRA
TURNS FIVE. Five
years ago NASA's Terra satellite began measuring
Earth's vital signs with a combination of
accuracy, precision, and resolution the world
had never before seen. Today, Terra completes
the fifth year in what was scheduled to be
at least a six-year mission to advance understanding
of Earth's climate system, and to help improve
our quality of life.
2005 Jan 11. NASA RELEASE:
05-018. NASA
Free Computer Model Available to Classrooms. A
free NASA global climate model is available
for high school and university desktop computers.
The Educational Global Climate Model (EdGCM),
available for both Windows and Mac platforms,
incorporates a 3-D climate model developed
at NASA's Goddard Institute for Space Studies
(GISS), New York. ... It runs on a desktop
computer to allow teachers and students to
conduct experiments identical to those scientists
run on supercomputers to simulate past and
future climate changes. "The
real goal of EdGCM is to allow teachers
and students to learn more about climate science
by participating in the full scientific
process, including experiment design, running
model simulations, analyzing data, and reporting
on results via the Web," said Mark Chandler,
lead researcher for the EdGCM project from
Columbia University, New York. For more information
about the EdGCM, visit: http://www.edgcm.org to download
EdGCM software from the Internet.
GLOBAL
GARDEN GETS GREENER In
the last two decades of the twentieth century,
in many parts of the global garden, the climate
grew warmer, wetter, and sunnier, and despite
a few El Niño-related setbacks, plants
flourished for the most part. A team of eight
scientists from across the country worked
for almost a year and half to pull together
satellite data on vegetation and ground- and
satellite-based climate observations.
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|
Chapters
- Three
Color Light
- Pixels
and Colors
- Measuring
Length in Digital Images
- Measuring
Area in Digital Images
- Exploring
and Measuring Light
- Spectral
Analysis
- Temporal
Analysis of Satellite Images
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7.
Temporal Analysis of Satellite Images
23 October 2007. SOUTHERN
CALIFORNIA WILDFIRES BURN OUT OF CONTROL:
NEW NASA SATELLITE IMAGES SHOW FIRES' RAPID
GROWTH.By Laura Spector, NASA Goddard
Space Flight Center. Excerpt:
NASA satellites continue to capture remarkable
new images of the wildfires raging in Southern
California. At least 14 massive fires are
reported to have scorched about 425 square
miles from north of Los Angeles to southeast
of San Diego.
The latest images, captured by NASA satellites on the afternoon
of October 22, show the thick, billowing smoke coming off the
numerous large fires and spreading over the Pacific Ocean.
Dry, drought-stricken vegetation and Santa Ana winds, which can
reach hurricane speeds, have contributed to the devastating effect
of these blazes.... According to news reports, almost 700 homes
have been destroyed and hundreds of thousands of residents have
been forced to evacuate.
...A pair of images, depicting the area around Los Angeles on
October 21, 2007, shows just how quickly the fires grew. According
to the National Interagency Fire Center, the blazes have burned
over 84,000 acres since they began over the weekend. Thousands
of residents have been evacuated from their homes and a state
of emergency has been issued for 7 California counties.
July 15, 2002, Urbanization's
Aftermath -- Using
satellite images of city lights at night,
[a group of researchers at NASA's Goddard
Space Flight Center led by biologist and
remote sensing specialist Marc Imhoff] constructed
a map of the urbanized areas of the United
States. They then retrieved vegetation density
readings of present day American cities
as well as simulated readings of the landscapes
that pre-dated these cities. By combining
the vegetation data with the urbanization
maps, Imhoff was able to calculate the effects
of urbanization on many types of ecosystems
across the country.
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|
Chapters
- Three
Color Light
- Pixels
and Colors
- Measuring
Length in Digital Images
- Measuring
Area in Digital Images
- Exploring
and Measuring Light
- Spectral
Analysis
- Temporal
Analysis of Satellite Images
Project
Gigalopolis: Urban and Land Cover Modeling |
