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Old 15th December 2006 | 23:09
  #6 (permalink)  
blackmail
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Joined: May 2003
Posts: 198
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From: france
nav problem

hi lemper,

very good point. in our example, the loxodrome is indeed special & equal to the parallel going through 60N from wpt 1 to wpt 2. the equator is also a special parallel as it is the only parallel that equals a great circle, supposed the earth is considered a perfect globus, which, of course, in reality it is not.

two more observations. first, problems as that occupies us here, have always some special/odd features in the question itself & it depends on the sharpness of the respondents mind to see this through & hind already in the good direction to find the correct answer. a good drawing to visualise the problem, associated with some basic formulae is always a good start. then, look back & reflect.

secondly, to elaborate on the "P O L E" acronym, this acronym can also be used when projecting ortho/loxo routes on common used maps.
to remember how the concave feature of these routes are, following may help:

lambert charts(used in mid latitudes) : ortho: concave towards its contact parallel. loxo : concave towards its pole.

mercator(used on equator & lower lat's) : ortho : concave towards equator( a special case of contact parallel). loxo : straight line.

stereopolair(used in mid to high lat's): ortho & loxo : both concave towards the pole.

i stop here, hoping not to have made a mistake & if so, please correct me.

kind regards,
bm
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