Instrument Abbreviation:
UI, VI, WI, UX, VY, WD, WS
Instrument Measurements:
a) Trace Gas
b) Cloud Physics/Aerosol
c) Radiation/Optical/Electrical
d) Additional Capabilities
3-dimensional wind gust measurement
Resource Person/Developer:
| Name: | Dick Friesen | Don Lenschow |
|---|---|---|
| Affiliation: | NCAR/ATD/RAF | NCAR/MMM |
| Phone: | (303) 497-1047 | (303) 497-8903 |
| Email: | rbf@ucar.edu | lenschow@ucar.edu |
Principle of Measurement:
The combination of three subsystems (Honeywell Inertial Reference System,
Trimble Global Positioning System and NCAR's radome gust probe sensors)
comprises the air motion system. The 3-dimensional wind (the basic
measurement obtained from this system) is obtained by subtracting the
3-dimensional ground speed from the 3-dimensional aircraft true airspeed.
In situ/Remote/Flux Measurement:
In situ
Field projects in which the instrument has been used:
most
Aircraft Platform:
all
Inlet Configuration/Location:
Aircraft nose
Calibration/Cross Calibration:
Aircraft intercomparison, special calibration maneuvers, tower fly-bys,
individual instrument component calibrations
Operator Requirements:
Data Collection:
external
Post-flight Data Validation, Processing, Hours per Flight Hour etc.
RAF NIMBUS software processor
Post-project validation by RAF Project Manager
Physical Characteristics:
Dimensions: (part of
airframe)
Weight:
Power:
This measurement system combines many individual measurements along with a complex mathematical expression to compute the wind gust data. Necessary measurements made by the airborne data system include:
True airspeed using radome dynamic pressure measured with a Rosemount Model 1221F1VL differential pressure transducer, static (barometric) pressure measured with a Rosemount Model 1501 absolute pressure transducer and total temperature measured with a Rosemount Model 102 temperature sensor;
Vertical and horizontal radome differential pressure measurements made with Rosemount Model 1221F1VL differential pressure transducers (combined with the dynamic pressure measurement to compute the attack and sideslip angles to provide the 3-dimensional true airspeed with respect to the aircraft's center line);
Aircraft attitude angles (pitch, roll and yaw) measured by the Honeywell Laseref SM Inertial Reference System to transform the aircraft's true airspeed to geographical coordinates;
Aircraft 3-dimensional ground speed (east, north and vertical components) measured by the Honeywell Laseref SM Inertial Reference System with long-term accuracy assured by measurements made by the Trimble TANS III GPS receiver.
Response Time:
0.1 s
Detection Limits:
0.05 M/s
Accuracy:
Precision:
Limitations (such as altitude, airspeed, etc.)