In The Institute - 2001-Sep, there is an article "UAV technology to aid in disasters". Incredibly, a mismatched mixture of units is used viz. [thousands of] feet and miles to quantify various altitudes above the earth's surface. How does one relate "100,000 feet" with "11 miles", "200 miles" etc.? Of course, one can say that 100,000 feet is about 20 miles or, one can employ a calculator to obtain 19+ miles (assuming that they know that there are 5,280 feet in a mile). But, I thought the IEEE was comitted to the use of SI units. In which case, the UAVs would fly at 30,000 m [translatable, sans calculator, to 30 km]; The communications tower (or low-orbit satellite) would be at 18 km etc. The use of mixed units is something one is used to seeing in (ASME) "Mechanical Engineer" but not to be expected in IEEE literature. Let us get back on the SI track! DT Bath, 861 Kensington Dr., Peterborough ON K9J 6J8 (705)743-4297
