Guest emrldjetta Posted September 4, 2001 Share Posted September 4, 2001 Any pilots or people who can help me: I am trying to use a GPS with an aeronautical chart but can't find what the datum used to construct the chart was. I have looked all around on the whole thing and in the legend but the only thing I can find that is even close to what I think I need to know is something called Lambert Conformal Conic Projection. I checked a known point in WGS84 against the chart and the longitude is right on but the latitude is off buy quite a bit. The chart is from 1970 and the scale is 1:500,000. OK guys, any help on this one? Thanx in advance....Kyle ------------------ It's always something............. Quote Link to comment
Guest Nemesis Posted September 4, 2001 Share Posted September 4, 2001 quote:Originally posted by emrldjetta:Any pilots or people who can help me....[maybe] I need to know is something called Lambert Conformal Conic Projection Maybe I can help. The projection simply strectches and distorts that part of the globe so that it will fit onto your flat paper map. It won't change the agreement or not of your point. In New Zealand at least, the newer aeronautical charts use WGS'84 (as far as I remember, I will check this when I get home). However, the locations of NDBs and VORs etc. use Geodetic Datum '49. This leads me to suspect that the older maps will use this datum too. Cheers, Donovan. Quote Link to comment
Guest Nemesis Posted September 4, 2001 Share Posted September 4, 2001 quote:Originally posted by emrldjetta:Any pilots or people who can help me....[maybe] I need to know is something called Lambert Conformal Conic Projection Maybe I can help. The projection simply strectches and distorts that part of the globe so that it will fit onto your flat paper map. It won't change the agreement or not of your point. In New Zealand at least, the newer aeronautical charts use WGS'84 (as far as I remember, I will check this when I get home). However, the locations of NDBs and VORs etc. use Geodetic Datum '49. This leads me to suspect that the older maps will use this datum too. Cheers, Donovan. Quote Link to comment
Guest emrldjetta Posted September 4, 2001 Share Posted September 4, 2001 Thanx for replying. I don't have Geodetic Datum '49 on either of my GPSRs. Perhaps it is peculiar to the southern hemisphere or NZ. ------------------ It's always something............. Quote Link to comment
Guest Nemesis Posted September 4, 2001 Share Posted September 4, 2001 quote:Originally posted by emrldjetta:Perhaps it is peculiar to...NZ. You may be right. BTW, I had WGS'84 and Geod Datum '49 mixed up in my previous message (I just checked my charts). You could try the datum that is most commonly used on maps locally. Cheers, Donovan. Quote Link to comment
Guest Kerry Posted September 5, 2001 Share Posted September 5, 2001 Geoditic datum '49 is specific ONLY to New Zealand and nowhere else and has been replaced by the geocentric datum NZGD2000 which for all intents and purposes is identical to WGS84. The difference between those 2 datum's is approx 200 metres. Position datum of charts should be marked on the chart somewhere. Cheers, Kerry. [This message has been edited by Kerry (edited 05 September 2001).] Quote Link to comment
Guest Cape Cod Cache Posted September 5, 2001 Share Posted September 5, 2001 I'm not an aviator, nor do I play one on TV, but considering the date, I'd wager on NAD27. I have some old NOAA charts that use NAD27, nice for decoration, but no more Nantucket lightship since the 1980's. All the current NOAA charts use WGS84 / NAD83. Quote Link to comment
Guest bwolv Posted September 5, 2001 Share Posted September 5, 2001 I am a Pilot, and an Air Traffic Controller. A chart from 1970 will be using NAD27. They swiitched to WGS84 a few years ago. Quote Link to comment
Guest emrldjetta Posted September 5, 2001 Share Posted September 5, 2001 Ok, just the type of feedback I was looking for. You guys are great, I knew there were "experts" here on many subjects. Cheers....Kyle ------------------ It's always something............. Quote Link to comment
Guest bwolv Posted September 5, 2001 Share Posted September 5, 2001 Happy Caching! Yup, there is a huge helpful group around here! Quote Link to comment
Guest Hallatauer Posted September 5, 2001 Share Posted September 5, 2001 quote:Originally posted by bwolv:I am a Pilot, and an Air Traffic Controller. A chart from 1970 will be using NAD27. They swiitched to WGS84 a few years ago. Just curious to know which facility you work in. I'm in ZNY. ------------------ Dan McLauglin 40 46.802N 73 07.630W Quote Link to comment
Guest bwolv Posted September 5, 2001 Share Posted September 5, 2001 I work at ZAN. Anchorage Alaska Enroute Center. I live in Eagle River, Alaska. You guys getting the ATOPs stuff soon? bwolv 61 15.462N 149 28.755W Quote Link to comment
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