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In this study, effect of change of explosive type on fragmentation is investigated. Two blast tests in which ANFO is used in the first and BARANFO 50 is used in the second one as the main blasting agent were conducted at Lafarge Yibita Lalahan Quarry. Both blasts were carried out at the same bench of the quarry having the same structural geology and same surface blast design parameters. The only varying parameter is the blasting agent. Both tests were monitored by continuous velocity of detonation recorder. Digital images were acquired from the muckpile after each blast test by using the same image sampling technique. Images were analyzed by using SPLIT software and size distributions of muckpiles obtained from both blasts were determined. SPLIT is a digital image processing software developed to compute size distribution of rock fragments from digital images. As a result of this research, it was shown that finer fragmentation is obtained by utilizing BARANFO 50 as the main blasting agent at a constant blasthole pattern. It is also shown that it is possible to expand the blasthole pattern as an alternative if the previous coarser fragmentation is preferred. Moreover, comparison of explosives should not be performed based solely on the purchase price. Since fragmentation affects all post-blast mining operations (loading, hauling, crushing, grinding, etc.), explosive performance should also be assessed by fragmentation evaluation using softwares which are proven to be accurate similar to SPLIT.

A perceived emerging threat to GNSS receivers is posed by a spoofing transmitter that emulates authentic signals but with randomized code phase and Doppler over a small range. Such spoofing signals can result in large navigational solution errors that are passed onto the unsuspecting user with potentially dire consequences. In this paper, a simple and readily implementable processing rule based on CNR estimates of the correlation peaks of the despread GNSS signals is developed expressly for reducing the effectiveness of such a spoofer threat. Consequently, a comprehensive statistical analysis is given to evaluate the effectiveness of the proposed technique in various LOS and NLOS environments. It is demonstrated that the proposed receiver processing is highly effective in both line-of-sight and multipath propagation conditions.