THE PROBLEM
The U.S. Navy's commitment to tracking tropical storms dates back
more than 50 years. In December 1944 during World War II, the Navy
encountered a typhoon in the Western Pacific in which many lives,
three ships and numerous aircraft were lost. After this tragedy,
naval personnel began a concerted effort to monitor the location
and intensity of tropical cyclones using dedicated aircraft to seek
out and locate tropical cyclones.
It wasn't until the mid-1960s that satellites
were first used to monitor weather, and by the early 1970s, these
satellites were utilized to monitor tropical cyclones. In 1987,
the Department of Defense began using a Special Sensor Microwave
Imager (SSM/I), a sensor employing microwave frequencies that permit
analysts to see through the upper layers of non-raining clouds.
This enabled analysts to see storm structure not feasible with standard
visible and infrared (IR) imagery.
When the NRL first began to analyze the
data recorded by the SSM/I, an in-house processing and visualization
software package was used. The software package was a multipurpose
suite of functions designed for analysts who work on and examine
images collected from a wide variety of satellites. To satisfy the
overall need to handle multiple sensors, the software required a
huge range of possible inputs. The time and effort to provide the
appropriate inputs proved burdensome to users who routinely dealt
with only one or two sensors.
The in-house software was thus robust, but
time-consuming for inspecting, processing and analyzing large numbers
of SSM/I images. The software permitted the user to thoroughly examine
an individual image, but its ability to handle multiple images of
the same tropical cyclone was inadequate. Additionally, the software's
user interface was cumbersome and time-consuming.
The
NRL's research efforts require software that gives users easy access
to thousands of SSM/I images from multiple tropical cyclones; easily
displays images from the same storm; creates SSM/I images and products
(e.g., wind speed, rain rate); enables rapid reprocessing of hundreds
of images in the background; permits recentering of storm centers;
provides a comment section for each image analyzed; and saves/archives
finished products so they remain easily accessible for future use.
THE SOLUTION
The NRL evaluated several software packages, including Research
Systems' IDL and XVT's development system, and PV-WAVE from Visual
Numerics was selected because it was easier to work with, had lower
associated maintenance costs, enabled the fastest development of
a working system, and most importantly, provided the most powerful
visualization capabilities. Using PV-WAVE in conjunction with existing
NRL scientific applications, TROPX (Tropical Cyclone Processing
System), a powerful visualization and analysis tool, was created.
PV-WAVE enabled the NRL staff to build a database from the 2,000
tropical cyclone images processed since 1987. Data collected from
all or any combination of the seven SSM/I channels was made available
to users, allowing them to derive key parameters such as wind speed
on the ocean surface and rain rates.
This data set is crucial to understanding the structures and intensities
of tropical cyclones. Intensity changes are a direct result of the
structural variations with time. The chief scientist and lead programmer
utilized PV-WAVE widgets and PV-WAVE to create rapid prototypes
and share them across the enterprise. Many "what if" scenarios
were discussed about how to efficiently lay out the graphical user
interface, and PV-WAVE widgets enabled changes to occur in minutes
instead of the hours or days it would have taken to do the same
with X Window calls.
RETURN
ON INVESTMENT
"Our objective has been to derive a method to extract tropical
cyclone intensities from the images captured by the SSM/I sensors,"
says Jeff Hawkins, meteorologist at the NRL. "For years it
has been difficult to accurately visualize a time sequence of SSM/I
tropical cyclone images. PV-WAVE has given us the ability to efficiently
process and display the large amounts of data captured by the satellites,
and to more easily visualize and classify key characteristics of
these storms including rain band structure, wind speed and rain
rate. Using PV-WAVE widgets has saved us hundreds of hours during
the course of the application development." He notes, "As
we continue to collect and save data from new storms, our ability
to accurately track and classify these storms will continue to improve.
This will position us to meet our ultimate goal - to help keep the
U.S. Navy's ships, aircraft, personnel and assets safe around the
world."
WORLD CLASS PRODUCTS, SERVICES,
AND SUPPORT
Visual Numerics has provided technical software
solutions for numerical analysis and visualization for over 30 years.
The company's software products help users understand complex data
from a variety of sources and build business-critical applications.
Visual Numerics offers two product lines: the IMSL® Numerical
Libraries for powerful mathematical and statistical analysis and
the PV-WAVE® visual data analysis development environment. Visual
Numerics also offers customized consulting services for applications
that involve mathematical, statistical, or visual data analysis
to meet today’s business analytical needs.
