Sökning: "head echoes"
Hittade 3 avhandlingar innehållade orden head echoes.
1. High-resolution meteor exploration with tristatic radar methods
Sammanfattning : A meteor observed with the naked eye is colloquially called a shooting star. The streak of light is generated by an extra-terrestrial particle, a meteoroid, entering the Earth’s atmosphere. The term meteor includes both luminosity detectable by optical means and ionization detectable by radar. LÄS MER
2. Radio meteors above the Arctic Circle : radiants, orbits and estimated magnitudes
Sammanfattning : This thesis presents results based on data collected with the 930 MHz EISCAT UHF radar system and three SKiYMet specular meteor radars. It describes in detail a method for meteoroid orbit calculation. The EISCAT UHF system comprises three identical 32 m parabolic antennae: one high-power transmitter/receiver and two remote receivers. LÄS MER
3. Characterization of the BOLD signal in functional MRI
Sammanfattning : In the last two decades, functional magnetic resonance imaging (fMRI) has become an important and widely used imaging technique for functional brain mapping. However, blood oxygen level dependent (BOLD) technique is quite insensitive and task invoked BOLD signal change at 3T is typically in the order of a few percent. LÄS MER