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Thread: Pressure charts

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    lustyd's Avatar
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    Default Pressure charts

    Hi all does anyone know the reason why pressure charts are presented as they are? I can't be the only one to find it confusing when something looks like it's going north east when in fact it's just going east.
    I can only assume there's a reason in there somewhere but seeing the ones that Simon uses which center on the pole I feel they are much clearer than the standard ones.
    Cheers
    Dave
    Vivacity 20, South Coast
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    ???? Pressure charts show isobars which are lines connecting points of same pressure. What's your problem?

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    lustyd's Avatar
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    Quote Originally Posted by awol View Post
    ???? Pressure charts show isobars which are lines connecting points of same pressure. What's your problem?
    The problem is that the lat and long are distorted and so it's much harder to tell north, east, south and west when compared to the pole version or even a square version where the land is distorted
    Vivacity 20, South Coast
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    Still can't see your problem

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    VicS is offline Registered User
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    Quote Originally Posted by lustyd View Post
    Hi all does anyone know the reason why pressure charts are presented as they are? I can't be the only one to find it confusing when something looks like it's going north east when in fact it's just going east.
    I can only assume there's a reason in there somewhere but seeing the ones that Simon uses which center on the pole I feel they are much clearer than the standard ones.
    Cheers
    Dave
    Quote Originally Posted by lustyd View Post
    The problem is that the lat and long are distorted and so it's much harder to tell north, east, south and west when compared to the pole version or even a square version where the land is distorted
    But aren't the charts you are objecting to pretty much the same as a sector cut from the type of charts that Simon uses.

    Are these the things you are having trouble with? Gnomonic projection??

    Last edited by VicS; 29-04-12 at 16:03.

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    lustyd's Avatar
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    Quote Originally Posted by awol View Post
    Still can't see your problem
    The problem is that following something to the East you must follow the curve. When something follows the curve it looks on first impression like its turning Northwards. While I do understand the charts, I was just curious as to the reason.
    Vivacity 20, South Coast
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    lustyd's Avatar
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    Quote Originally Posted by VicS View Post
    But aren't the charts you are objecting to pretty much the same as a sector cut from the type of charts that Simon uses.

    5.jpg[/IMG]
    I suppose they are yes, but with the whole chart you can easily see the weather circling the pole.
    Vivacity 20, South Coast
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    All representations of parts of a sphere (or oblate spheroid for the pedants) in 2-dimensions have to be distorted. Which projection would you prefer? Mercator might suit your prejudices.

    The one that really annoys me is the Beeb weather map of the UK which seems to be drawn with the perspective as if seen from the top of the Eiffel Tower.

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    Quote Originally Posted by awol View Post
    All representations of parts of a sphere (or oblate spheroid for the pedants) in 2-dimensions have to be distorted. Which projection would you prefer? Mercator might suit your prejudices.

    The one that really annoys me is the Beeb weather map of the UK which seems to be drawn with the perspective as if seen from the top of the Eiffel Tower.
    That probably would be my preference but doesn't answer why the weather maps are the way they are. I was hoping there would be a good reason in there somewhere, perhaps I'll ask again when Simon is back from hols
    Vivacity 20, South Coast
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    Easticks28 is offline Registered User
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    God, what do they teach 'em in Geography these days?

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