This study investigates the geometric accuracy of DSMs and orthoimages, which are obtained from high resolution satellite stereo pairs of in-track, cross-track and mixed satellite images. Four IKONOS and two QuickBird panchromatic images are used to constitute 15 stereo pairs, and are processed to generate DSMs and orthoimages. A geometric stereo model, which represents the stereo acquisition g...

Since the successful launch of DigitalGlobe’s QuickBird satellite and the availability of the data, QuickBird Imagery has quickly become the best choice for large scale mapping using high-resolution satellite images. First, the satellite has panchromatic and multispectral sensors with resolutions of 61-72cm (2-2.4ft) and 2.44-2.88m (8-9.4ft) respectively, depending upon the off-nadir viewing an...

The role of the hippocampus in spatial cognition is incontrovertible yet controversial. Place cells, initially thought to be location-specifiers, turn out to respond promiscuously to a wide range of stimuli. Here we test the idea, which we have recently demonstrated in a computational model, that the hippocampal place cells may ultimately be interested in a space's topological qualities (its co...

A pattern recognition strategy for the HERA-B main tracking system is presented. A concurrent track evolution algorithm has been developed to select the optimal track candidate compatible with a seed. Intrinsically a local method, it combines the virtues of track following procedures with the necessary ability to optimize between many available paths in a high occupancy environment. The problem...

A train in motion applies moving steady loads to the railway track as well as dynamic excitation; this causes track deflections, vibration and noise. At low frequency, the spectrum of measured track vibration has been found to have a distinct pattern; with spectral peaks occurring at multiples of the vehicle passing frequency. This pattern can be analysed to quantify aspects of train and track ...