Multitarget detection using Kalman-based average displacementestimator

The anomaly in the displacement estimates obtained from a low-level Kalman-based average displacement estimator is used to detect multiple targets in a forward-looking infrared (FLIR) scene. The displacement estimates originating from the targets could be associated with the detected multiple targets and an updated estimated position of the target could be obtained. This procedure could be repeated for all targets in the scene to obtain multitarget tracking. The behavior of the expected value of the displacement estimates as a function of the number of iterations is investigated. The behavior of the displacement error covariance matrix and the Kalman gain matrix are discussed as functions of the number of iterations     

The Swedish Interplanetary Society (1950–1969) and the formation of IAF and IAA

With a growing interest for rocket technology and space travel after WW II a number of new “space societies” were formed in the period 1948–1951 in addition to the ones already existing in Germany, the UK and the US since before WW II. Soon came the need for a common international platform for exchange of information and experience, and the concept of an international federation of astronautical societies emerged.Sweden was one of the 8 countries to sign the original declaration to create an International Astronautical Federation on October 2, 1950 in Paris at the 1st International Astronautical Congress. The Swedish Society for Space Research (Svenska Sällskapet för Rymdforskning) was formed a few days after the historical event in Paris. The name was soon to be changed to the Swedish Interplanetary Society (Svenska Interplanetariska Sällskapet, SIS). Sweden was one of the 10 countries to sign the IAF foundation in 1951 in London and in the following year the first Constitution of IAF in Stuttgart.The SIS quickly grow to a membership of several hundred persons and its membership in IAF promoted an intensive exchange of journals, and the annual participation at the IAC gave growth to start study projects on spacecraft and sounding rockets, and the publication of astronautical journals in Swedish. In 1957 the first Swede was elected vice-president of IAF.Not too long after the IAF foundation the idea of an international body of distinguished individuals emerged, in addition to the body of "member societies" (IAF). Upon the initiative of Theodor von Karman, Eugen Sänger and Andrew Haley the IAF council approval of an International Academy of Astronautical was given on August 15, 1960 during the 11th IAC in Stockholm. This IAC in Stockholm gave a large publicity to space research and astronautics in Sweden, and put the activities of the SIS in the focus of the general public.This paper presents the Swedish involvement in the foundation of IAF and IAA. It also gives an overview on the positive influence of these two organisations on the work and progress of the Swedish Interplanetary Society and the diffusion of astronautics to the general public in Sweden.     

Rigidity Dependence and Time Response of Cosmic Rays to the Modulation Steps in the Rising Part of Solar Cycle 23. Cospin/ket Results

Previous work on the latitudinal gradient and on the amplitude of the recurrent cosmic ray decreases, has shown that their magnitude does not decrease monotonically with the particle rigidity, but it presents a broad maximun around 1–2 GV. We have extended this analysis to study the behaviour of cosmic-ray particles during the modulation steps in the rising part of the solar activity of the present Solar cycle. We found that the ‘depth’ of the modulation step decreases monotonically with increasing rigidity and that the least energetic particles are the last to reach their minimum intensity value. We also considered in this analysis electrons of equal rigidity to study the influence of the charge sign on the particle behaviour during the modulation steps. This revised version was published online in August 2006 with corrections to the Cover Date.     

The human cardiovascular system during space flight

Purpose of the work is to analyze and to summarize the data of investigations into human hemodynamics performed over 20 years aboard orbital stations Salyut-7 and Mir with participation of 26 cosmonauts on space flights (SF) from 8 to 438 days in duration. The ultrasonic techniques and occlusive plethysmography demonstrated dynamics of changes in the cardiovascular system during SF of various durations. The parameters of general hemodynamics, the pumping function of the heart and arterial circulation in the brain remained stable in all the space flights; however, there were alterations in peripheral circulation associated with blood redistribution and hypovolemie in microgravity. The anti-gravity distribution of the vascular tone decayed gradually as unneeded. The most considerable changes were observed in leg vessels, equally in arteries (decrease in resistance) and veins (increase in maximum capacity). The lower body negative pressure test (LBNP) revealed deterioration of the gravity-dependent reactions that changed for the worse as SF duration extended. The cardiovascular deconditioning showed itself as loss of descent acceleration tolerance and orthostatic instability in the postflight period.     

On electromagnetic phenomena in Mercury’s magnetosphere

Mercury has a small but intriguing magnetosphere. In this brief review, we discuss some similarities and differences between Mercury’s and Earth’s magnetospheres. In particular, we discuss how electric and magnetic field measurements can be used as a diagnostic tool to improve our understanding of the dynamics of Mercury’s magnetosphere. These points are of interest to the upcoming ESA-JAXA BepiColombo mission to Mercury.