Knot (unit) fluids (tidal streams, river currents and wind speeds) are also measured in knots. Thus, speed over the ground (SOG) (ground speed (GS) in aircraft) and rate of progress towards a distant point ("velocity made good", VMG) are also given in knots. Until the mid-19th century, vessel speed at sea was measured using a chip log. This consisted of a wooden panel, attached by line to a reel, and weighted on one edge to float perpendicularly to the water surface and thus present substantial resistance to the water moving around it. The chip log was cast over the stern of the
Wind power in Thailand highest wind energy potential in Thailand. The stations were installed to measure wind speeds at 80, 90, and 100 m heights. Also, from 2007 to 2009 wind speed and direction were measured and recorded from several stations in the northern Thailand. In 2011, research to improve the wind map was conducted by the Department of Physics of Silpakorn University. The research produced mesoscale wind maps with resolution of 3x3 km cells using atmospheric model and computer simulation software, and also experimented with the making of microscale wind maps, which could be the next step in the study of Thai wind