Observing Systems

NOAA P-3

Tail Radar Data
The tail radar on the P-3 is a Doppler radar and provides detailed measurements of the vertical and kinematic (wind) structure of storms in a swath roughly 80 km wide (40 km on either side of the aircraft). These data have proved especially useful in research, and will provide real-time measurements of the intensity of precipitation and depth of the storm, as well as the height of the freezing level that will be included in the reconnaissance message.



Data from the P3 Tail radar during CALJET.
Fuselage Radar Data
The belly radar is not a Doppler radar, but it provides radar reflectivity measurements out to a range of roughly 200 km. This capability allows on-board assessment of the position, orientation, and strength of rain bands. Rain band motion can be determined by tracking them over roughly an hour.



Data from the P3 Fuselage Radar during CALJET.

Wind Profiler Network

CRPAQS basemap
Profiler deployment for CRPAQS.

Satellite Products

Cooperative Institute for Meteorological Satellite Studies (CIMSS)
Real-time GOES winds.
Specialized GOES wind products based on a feature tracking technique were produced by CIMSS as part of the CALJET experiment in 1998. A unique component of this data set is the availability of super-rapid-scan (1-min sampling) GOES images. These data were used to assess the impact of shortening the time between images used in feature tracking. Standard approaches used 30-min between samples, but tests in tropical storms had suggested more frequent sampling could improve areal coverage in regions where cloud features had a shorter lifetime than 30 min. The figures shown here represent the results of this test using a 5-min lag between images for both IR and visible channels. These are compared to results using 30 min lag, and confirm that the areal data coverage increases significantly. Using statistical internal consistency checks it was determined that the optimal time lag was about 5-min. Wind vectors calculated using shorter lags had higher internal variance that resulted from the increased influence of satellite pointing uncertainty as the distance between features decreased, i.e., with shorter time lags. Based on these results, a new GOES scan pattern is being developed that should provide a set of 3 consecutive 5-minute interval images, once every hour around the clock during PACJET over the domain shown here. In addition to the GOES wind products, GOES sounder moisture products (total precipitable water vapor, and cloud-top pressure) will be available at 3-hourly intervals.

GOES-9 VIS Cloud Drift Winds
30 Min Data
Using Routinely Available Data
(30 Min)
5 Min Data
Using Super Rapid Scan Data
(5 Min)
GOES-9 IR Cloud Drift Winds
30 Min Data
Using Routinely Available Data
(30 Min)
5 Min Data
Using Super Rapid Scan Data
(5 Min)
Cloud Parameters
Cloud
Cloud Top Pressure
Total Water Vapor
Total Precipitable Water Vapor

Cooperative Institute for Research in the Atmosphere (CIRA) AMSU Data
Tutorial: Polar Satellite Products for the Operational Forecaster: Microwave

Cloud Liquid Water
Cloud Liquid Water
Rain Rate
Rain Rate
AVN Geopotential Height
AVN Geopotential Height
AMSU Geopotential Height
AMSU Geopotential Height

Sband data S-band data
Sband Radar deployed for CALJET S-band radar deployed at CALJET

ETL S-band Radar

A new S-band vertical profiler with a coupler option for extending the dynamic range of the radar's receiver has been developed by the NOAA Environmental Technology Laboratory and successfully field tested during CALJET. The 30 dB of added dynamic range provided by the coupler allows the profiler to record radar reflectivity measurements in moderate-to-heavy precipitation that otherwise would not have been possible with this system because of receiver saturation. The radar hardware, signal processor, and operating software are based on existing S-band and UHF profiler technology developed at the NOAA Aeronomy Laboratory. Results from a side-by-side comparison with the NOAA K-band radar were used to determine the calibration and sensitivity of the S-band profiler. In a typical cloud profiling mode of operation, the sensitivity is -14 dBZ at 10 km or -25 dBZ at 3 km. During CALJET, the profiler was deployed at Cazadero, California, near the crest of the coastal mountains in a region climatologically prone to flooding. The profiler was part of an integrated observing system designed for measuring physical processes associated with orographic precipitation enhancement. The CALJET S-band dataset is also being applied to the problem of quantitative precipitation estimation using the WSR-88D (NEXRAD) network.