The NCAR 449 MHz Modular Wind Profiler Development

Bill Brown, Steve Cohn, Brad LindsethTerry Hock, Charlie MartinNCAR / EOL

Jim Jordan, Dan Law, Warner EcklundNOAA

Also collaborating with other groups (eg, University of Oklahoma)

“Workhorse” systems for many years.Mature stage of life-cycle Today’s technology ready to go higher and faster

•Three 915 MHz Wind Profilers with RASS

• Winds to ~3 km, temperature to ~ 1km

• 30-min time, 60-105 m height resolution

• Over 40 deployments since 1992

• Advances: MAPR spaced-antenna, Mobile-ISS, Ship operations

Legacy 915 MHz Wind Profilers

A larger network of boundary layer systems

Unmet needs based on years of requests

Also collaborative opportunities……

Winds to higher altitudes

Better time resolution

Simplified instrument setup and autonomy

A testbed for algorithm/technique development

Example: T-REX

Boundary Layer Config.3 antenna modulesNetwork of 6

Mid-Tropospheric Config.7 antenna modulesNetwork of 2

Lower Stratospheric Config.19 antenna modules

200 m – 7 km30-200 m

300 m – 15 km100-200 m

Range:Resolution:

150 m – 4 km30 m

Not

to s

cale

!

One module

449 MHz Modular Wind Profiler449 MHz gives us the rangeModularity gives us the flexibility

Modular Profiling Network(with 19 antenna modules available)

One station that samples throughout the troposphere

Two stations that sample a deeper cross-section downwind of the mountain range

Six stations that sample the boundary layer of an urban basin

Many configurations, one system, broad science

First deployment of 3-antenna prototype

PCAPS (Persistent Cold Pool Study)

Salt Lake, Utah, Dec 2010 - Feb 2011

Side-by-side comparison:• 915 MHz wind profiler• 449 MHz wind profiler (3 modules)

449 MHz Wind Profiler

915 MHz Wind Profiler

(N.B. a lot of fiddling and changes during the 2-months!)

449 MHz

915 MHz

449 Profiler Winds• Hardware performed well for most of 2-months

• Better 449 altitude coverage than 915

• Better time resolution is possible

• Captured the interface between valley flow and mountain crest flow (important for PCAPS science)

A day of 30-min winds

449 MHz Comparison with 915 MHz

449

915

449 MHz Comparison with 915 MHz

449915 High

915 Low

Winds percentagevs. Height

• Altitude coverage about 1 km greater

• 2 months of operations

• Median absolute difference < 2 m/s

449 MHz: 5-minute wind resolution

4 hours

449 Next Steps 3-panel prototype works well. Some outstanding

questions (e.g. algorithm details; minimum range)

Has allowed us to test components and concepts

Next steps:o Build seven antenna modules

o One 7-panel profiler or two 3-panel systems(Two BL or one mid-troposphere profiler)

o Status:o Construction underway (working around other commitments)

o Testing prototype next summer

Longer term: Mobile-449/ISS, RASS (Tv), Range Imaging Eventually…develop full 19-module system Early discussion: how to adapt for ship operations