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Wed, 5 May 1999 16:30:46 -0400 |
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--- Begin Forwarded Message ---
Date: Tue, 4 May 1999 11:58:59 -0700
From: Jenny Stone <[log in to unmask]>
Subject: Fw: polyconic projection
Sender: Jenny Stone <[log in to unmask]>
Greetings. I've got a stumper of a question about USGS historic maps, quoted
below. I can find details on the polyconic projection, as well as the
equations used to calculate the meridian, etc., but I can't find the actual
parameters that were used by USGS in Washington during that time. Does
anyone have any ideas where I might find that?
Thanks.
Jenny Stone
___________________________________
GIS Librarian * Map Collection
University of Washington Libraries
Box 352900 * Seattle, WA 98195-2900
phone: 206.543.9392
-----Original Message-----
Subject: polyconic projection
|Jenne,
|I have a question for you related to digitizing a paper map. The map I am
|digitizing is a 1898 USGS landcover map. It has a lat/long graticule for
|reference coordinates. Based on the date I am assuming the map used the
|Clarke 1866 spheroid and the polyconic projection. I am also assuming a
|local datum, although it is possible it is connected to one of the earlier
|American datums. From looking at Arc/Info help it seems that I need the
|datum for the map and parameters for the map such as central meridian,
|parallel of origin, false northing and false easting. Do you know if this
|information is available and/or whether it is necessary. Thanks for any
|help you can provide.
--- End Forwarded Message ---
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