System design for ARTEMIS environmental monitoring

This paper describes aspects of system design applied to the ARTEMIS environmental monitoring system of the Food and Agriculture Organization (FAO) of the United Nations. The design aspects are derived from characteristics of the monitoring function and are based on methods of rainfall and vegetation monitoring from satellite observations which...

Ageing aircraft research in The Netherlands

The problems of Ageing Aircraft are worldwide. Hence, actions to overcome or prevent these problems should be taken in international collaboration. The Federal Aviation Administration FAA and the Netherlands Civil Aviation Department RLD have signed a Memorandum of Cooperation in the area of structural integrity, with specific reference to...

Standardized environmental fatigue sequence for the evaluation of composite components in combat aircraft (ENSTAFF = ENvironmental FalSTAFF)

Fatigue life assessment of composite structures in fighter aircraft necessitates testing with both mechanical and environmental loading at both coupon and structural element size levels. Testing facilities to run such tests are now available but environmental fatigue testing is expensive and time consuming. An environmental fatigue loading...

Studie naar de opzet van een nationaal ERS-1 datacentrum - Phase-A/B study of a national ERS-1 data centre

Within the framework of the National Remote Sensing Programme and under contract with the Netherlands Remote Sensing Board (BCRS), the National Aerospace Laboratory NLR has carried out a Phase-A/B study of a national ERS-1 data and information centre. The first European Remote Sensing Satellite (ERS-1) is due to be launched by the European Space...

Crop identification with microwaves (SLAR-data of 1985)

Microwaves (i.e. X-band SLAR) have been used in The Netherlands for many years within ROVE to identify agricultural crops. This report deals with data acquisition, preprocessing and classification of agricultural crops in The Netherlands using the Dutch Digital SLAR. With internal and external calibration of the instrument satisfactory results...

Experimental and system study of Reaction Wheels. Part I: Measurement and statistical analysis of force and torque irregularities

Torque and force irregularities of running reaction wheels were studied. In this first part of the study report results from noise measurements at constant wheel speeds on various types of current technology European reaction wheels, both with ball- and magnet bearings and with DC or AC drive motor, are presented. The measured noise in radial...

Study of an attitude acquisition measurement technique using the ESA starmapper: Part I: Executive summary

The study deals with the rotational motion of a spin-stabilized spacecraft equipped with a V-slit sun sensor and the X-slit ESA starmapper. Assuming complete absence of an a priori attitude estimate, it is required to produce a rough estimate of the spacecraft attitude motion. It was assumed that sensor misalignments, external torques and...

Study of an attitude acquisition measurement technique using the ESA starmapper: Part two: final report

The study deals with the rotational motion of a spin-stabilized spacecraft equipped with a V-slit sun sensor and the X-slit ESA starmapper. Assuming complete absence of an a priori attitude estimate, it is required to produce a rough estimate of the spacecraft attitude motion. It was assumed that sensor misalignments, external torques and...

Gyro noise measurement and analysis

Noise measurements were performed on two identical space qualified gyroscopes of the floated rate integrating type (Perranti Type I25) in an analog rehalance loop configuration of selectable loop bandwidth, running under space representative conditions. The noise frequency range of interest was O.OO5 Hz to 50 Hz. The noise results were processed...