Identification

Title

A Kalman Filter to Improve Measurements of Wind from NSF/NCAR Research Aircraft

Abstract

To improve the measurements of wind made from NSF/NCAR aircraft, a Kalman filter is developed and applied to archived data files from research projects. The filter is an error-state Kalman filter, and the emphasis is on improving the measurements of pitch and heading because they are usually the dominating source of uncertainty in measured wind. The NSF/NCAR Gulfstream V research aircraft is emphasized in the development, but the filter as developed can be applied to data from other present and past NCAR aircraft as well. So that the resulting filter can be applied in cases where the primary measurements from the inertial reference system were not recorded in the data file, a method is developed for retrieving those measurements by differentiating the recorded variables representing attitude angles and aircraft-velocity components. In addition, some new algorithms are introduced for estimating the rate of climb of the aircraft from the measured accelerations and for estimating the angle of attack from pressures measured at ports on the radome. In addition, simplified methods for estimating the errors in pitch and heading without the full complexity and processing requirements of the Kalman filter are documented. The result is that standard uncertainties in pitch and heading are reduced to about 0.01, so that they no longer dominate the uncertainty in the wind measurements. Some examples illustrate the effects of the Kalman filter on measured wind and on variance spectra. The processing technique is incorporated into an R script that can add the improved variables to a standard netCDF data archive so that they can be made available for community use. Documents that are accessible via links in this technical document provide information on the workflow that generated the document, the details of the processing algorithms, and instructions for use and modification of the processing script.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d7tf00v8

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

Keyword set

keyword value

EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC WINDS > WIND DYNAMICS > VERTICAL WIND VELOCITY/SPEED

EARTH SCIENCE > SPECTRAL/ENGINEERING > PLATFORM CHARACTERISTICS

EARTH SCIENCE SERVICES > DATA ANALYSIS AND VISUALIZATION > STATISTICAL APPLICATIONS

EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC WINDS > UPPER LEVEL WINDS > FLIGHT LEVEL WINDS

originating controlled vocabulary

title

U.S. National Aeronautics and Space Administration Global Change Master Directory

reference date

date type

revision

effective date

2021-09-17

Geographic location

West bounding longitude

East bounding longitude

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2017-09-26T00:00:00Z

Frequency of update

Quality and validity

Lineage

Conformity

Data format

name of format

version of format

Constraints related to access and use

Constraint set

Use constraints

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata date

2023-08-18T18:06:26.998640

Metadata language

eng; USA