Experiences with two GPS SPS receivers in northern Europe

Results are given of measurements with two hand-held GPS C/A- code SPS (Standard Positioning Service) receivers at thirty locations in Finland, Norway and Sweden. Comparison is made between computed positions by the receivers and positions on geographic maps. It is concluded that both receivers have pros en cons. A combination of the...

Revised results of the unsteady transonic pressure measurements on the LANN model

A new postprocessing procedure is applied on the data, acquired in 1981 during the unsteady transonic pressure measurements on a transport-type supercritical wing (LANN-model), oscillating in pitch. The new procedure takes the influence into account of the local boundary layer on the dynamic response of the pressure tubes. This report presents...

Development of a multi-component internal strain-gauge balance for model tests in a cryogenic wind tunnel

A three-component internal strain-gauge balance for use in a cryogenic wind tunnel has been developed by NLR. With this balance model tests were performed in the NASA 0.3-m Transonic Cryogenic Tunnel. The results are discussed with a view to the development of strain-gauge balances for the ETW.

Meetfouten bij intensiteitsmetingen, toegepast op de bepaling van geluidsisolatie

A study has been carried out on the errors, connected with acoustic intensity measurements, measuring the sound transmission loss of panels with the intensity method. The magnitude of some measuring errors can be estimated from available publications. From measurements in a standing wave tube and on a flat plate the measuring errors have been...

Processing of Meteosat attitude measurement flight data and evaluation of the performance of an adaptive filtering technique

The attitude measurement data of the ESA geosynchronous spacecraft METEOSAT have been analyzed using an adaptive recursive filtering technique developed at NLR. The mathematical models of spacecraft dynamics and sensors have been kept very simple. Modelling errors are such that, without adaptive feed-back, strong divergence of the filtering...

Investigation of a cross-coupling drift compensation method on a single axis gyro stabilized platform

In this report the phenomenon of cross-coupling drift (both S-IA and S-OA) due to vehicular angular movements is investigated. In a hardware test set-up, using an experimental Single Axis Platform composed of surplus parts from the former Eldo-A program, the theoretical result as well as a proposed method of compensation is verified.