UAS Hurricane Testbed 2pger

							               Unmanned Aircraft Systems
            NOAA’s Hurricane Unmanned Aircraft Systems Testbed
The National Oceanic and Atmospheric Administration (NOAA) is working to use Unmanned Aircraft
Systems (UAS) to improve its ability to monitor the global environment by filling critical gaps in our
current measurement systems over remote and dangerous areas. NOAA’s UAS Project is establishing
regional testbeds to evaluate the research and operational potential of the aircraft.
The Problem
Hurricanes and tropical storms cause many deaths and average billions of dollars in damages each year.
In 2005, more than 1000 lives were lost in Hurricane Katrina alone, and the financial impact on the U.S.
economy has already exceeded $200 Billion. In response, plans are underway to enforce mandatory
evacuation of coastlines, including providing buses to allow nearly 100% of residents to leave when
Category 4 or 5 storms are predicted to hit the coast. The cost of these mandatory evacuations, which
could average as much as once yearly, will be in the billions of dollars. The stakes are high. Forecast
errors in either direction are expensive. Money spent to improve the accuracy of hurricane prediction is a
good investment.
Improved forecasts and warnings have demonstrably saved lives and property. They also reduce the costs
inherent in responding to the hurricane threat. The devastating impacts of Hurricanes like Katrina or
Wilma (2005) require that we make the best possible and most authoritative information available to
decision-makers to help them determine whether to implement mandatory evacuations and other costly
actions for approaching hurricanes.
Based on the current state of science and our operational system, we can expect generally good track
predictions, but there are occasional substantial errors in intensity, particularly for rapidly intensifying or
rapidly weakening storms. The extent of damage is determined by the size and structure of the storm.
Even the track can sometimes be uncertain. Note the various model tracks forecast for Hurricane Rita as
it approached the Gulf of Mexico (Fig. 1). Such a wide variation indicates room to improve tropical storm
observations and models. No matter how good the models and forecasters are, the current poor state of
offshore observing will result in occasional large misses in track and intensity in the 2 to 4 day forecasts. A
NOAA is steadfastly working with its international and domestic partners to cost-effectively increase the
number, breadth, accuracy, and availability of observing systems. As part of this effort, NOAA is
number                                          investing in new technologies, such as UAS in order to
                                                improve the accuracy and timeliness of our Nation’s
                                                existing weather observation and forecast system.
                                                Ultimately, the value of this proposed work will be
                                                measured in lives and money saved from improved
                                                understanding, forecasts and preparation.
                                                                UAS Hurricane Prediction Improvements
                                                                There are several operational and scientific issues that
                                                                need to be addressed to improve hurricane intensity
                                                                prediction. They include:
                                                                The cycle of eye-wall replacement. This cycle is
                                                                widely recognized as a key determinant of hurricane
Fig. 1 - Hurricane forecasters use “guidance” from models       intensity. It will never be well characterized by
that are based on observations. If the models agree, they can
make forecasts with high confidence. This guidance for          intermittent measurements - it will only be understood
“Rita” shows a high degree uncertainty.                         and predicted when we have the ability to continuously
                                                                monitor the full
             Unmanned Aircraft Systems
monitor the full spatial and temporal structure of these cycles. The continuous monitoring of the storm
inner structure that could be made with UAS could provide, in combination with satellites and other
observing systems, the data needed to understand and predict these cycles.
Air-Sea Interaction. The interaction between the ocean and the hurricane is important, complex, and not
well handled in current observing systems and models. This lack of understanding is primarily due to the
limited availability of detailed observations within the storm near the air-sea interface. To this end, an
enhanced system of ocean and coastal buoys in concert with an aggressive program to utilize low level
UAS designed to penetrate and sample the violent low level hurricane environment would help fill this
critical data void.
Hurricane Environmental Interaction. The inner-core of a hurricane is a relatively small structure
dependant upon the surrounding atmospheric environment to sustain its strength. To make a good several-
day prediction, the winds, temperature and moisture structure of the air for a thousand plus mile radius
around the storm are crucial determinants. A program that would use more manned and unmanned
aircraft measurements in the large domain around the storm, and that would make more effective use of
our satellite observing systems, could improve the intensity and track forecasts.
Proposed Program
                                                    The proposed coordinated strategy would use High-Altitude
                                                    Long-Endurance (HALE) and Low-Altitude Long-Endurance
                                                    (LALE) UAS to augment existing observational platforms
                                                    (satellites, manned aircraft, in-situ observations). The United
                                                    States has developed and currently deploys HALE-class
                                                    UAS. An example is Northrop Grumman’s Global Hawk
                                                    (Fig. 2). These aircraft have the advantage of being able to
                                                    continuously monitor storms for long periods. A possible
                                                    operations concept would be to deploy a HALE-class UAS at
                                                    60,000 feet, well above the hurricane in the smooth clear air
                                                    of the stratosphere, to take both remote and in-situ
                                                    measurements to continuously monitor the storm intensity.




Fig. 2. - Use of HALE-class UAS for high-altitude
hurricane reconnaissance. (MacDonald and Surgi)

These high-altitude measurements would
be augmented by complementary low
altitude missions that would utilize the
unique attributes of LALE-class UAS
such as the Aerosonde. Multiple low
flying LALE-class UAS would be used to
collect critical measurements very close
to the ocean surface within the hurricane           Fig. 3. - Aerosonde (blue) and P-3 (red) flight tracks into tropical storm Ophelia
eye, eye-wall, and surrounding region               on September 16, 2005. This mission marked the first ever successful unmanned
                                                    flight into a tropical cyclone. Storm intensity at the time was 55kts. Aerosonde
(Fig. 3).             (http:/uas.noaa.gov)          flight altitude within the storm varied between 300-800m.