INSIGHTS

摘要

Christopher columbus was already a master navigator when, on May 30,1498, he embarked on his third voyage of discovery. This expedition, however, which ultimately carried his six-strong fleetto Venezuela's Paria Peninsula, provided lessons in magnetic declination and governing practices. As he sailed west, Columbus noticed that the angle between north, as registered on his magnetic compass, and north, as measured by his lodestar, was changing. Columbus likely understood that this angle fluctuated over time and with his latitude and longitude, and he definitely understood that navigational ambiguity wouldn't be a crew-pleaser, so he factored corrective measurements into his dead-reckoning navigation, While his tactic worked, contemporary heading sensors greatly simplify navigation. For example, mechanical gyrocompasses, nine-axis compasses and GPS receivers can deliver heading or course-over-ground (COG) data to networked instrumentation. However, these solutions have their drawbacks. Gyrocompasses require regular maintenance, nine-axis.