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Well, having a look at the UKHO example, compare a. (full seafloor coverage (multibeam)) with entries: e. , f. and l. (leadline) As a regular practicing navigator I’d be inclined to treat the first as rather more reliable than the rest…especially if I was thinking about anchoring depths for an overnight stop with the sort of tidal range they have in the Channel Islands/Iles Anglo-Normandes (which are what are shown) of something like 10m, 33’. So yes, a value judgment and not always an improper one. Stephen D Dr Stephen Davies CSSC Maritime Heritage Research Fellow Hong Kong Maritime Museum g/f Murray House, Stanley Plaza, Stanley, Hong Kong SAR, China Tel: (+852) 2813 2322 Fax: (+852) 2813 8033 www.hkmaritimemuseum.org -------------------------------------------------- HKMM is moving to Central Pier 8 in 2012 ! 香港海事博物館將於2012年遷往中環八號碼頭! From: [email protected] [mailto:[email protected]] On Behalf Of John Day Sent: 17 September 2011 02:12 To: Discussion group for map history Subject: RE: [MapHist] Looking for a map with a specific kind of reliability diagram Disclaimer: I have nothing useful to add to this discussion. ;-) Now, let me ask a naive question: Isn't there a value judgement being place here calling these "reliability" charts? Doesn't that presume that latter measurements are more reliable than earlier ones? I realize that this is the term that is used, but isn't this more analogous to the "References" section of paper? IOW, what were the sources for the data. Sorry for the distraction. This is a MapHist list message (when you hit 'reply' you're replying to the whole list) o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + Content-Type: multipart/related; boundary="----=_NextPart_000_0120_01CC745E.44C4D580" Content-Language: en-gb Dear Dana, The only examples I come across regularly appear on British Admiralty charts, but only those published as of some time (sorry to be vague) around the last couple of decades of the 20th century. An exact date could be got from Guy Hannaford ([email protected]), the UKHO archivist who is extremely helpful. It is possible this is as a result of an International Hydrographic Organization standard. Here is an example: Before that date reliability indications as to survey data were loosely noted in the chart colophon, but only in terms of the date of the most recent survey and the ship and surveyors who did it. There was sometimes a reference to previous surveys where that data was incorporated in the new chart. Otherwise indications of reliability were given by convention - e.g. for vigias. In addition, for soundings (when individual soundings rather than depth contours were the norm) a different font was used (usually italic) to indicate soundings from previous charts of doubtful reliability. Hope that helps. Stephen D Dr Stephen Davies CSSC Maritime Heritage Research Fellow Hong Kong Maritime Museum g/f Murray House, Stanley Plaza, Stanley, Hong Kong SAR, China Tel: (+852) 2813 2322 Fax: (+852) 2813 8033 www.hkmaritimemuseum.org -------------------------------------------------- HKMM is moving to Central Pier 8 in 2012 ! çÅç`äCéñîéï®äõíâó2012îNëJâùíÜä¬îÂj·˜ì! -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Dana A. Freiburger Sent: 16 September 2011 01:10 To: Discussion group for map history Subject: [MapHist] Looking for a map with a specific kind of reliability diagram This is a MapHist list message (when you hit 'reply' you're replying to the whole list) o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + o + _______________________________________________ MapHist: E-mail discussion group on the history of cartography hosted by the Faculty of Geosciences, University of Utrecht. The statements and opinions expressed in this message are those of the author and do not necessarily reflect those of the University of Utrecht. The University of Utrecht does not take any responsibility for the views of the author. List Information: http://www.maphist.nl Maphist mailing list [email protected] http://mailman.geo.uu.nl/mailman/listinfo/maphist
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_______________________________________________ MapHist: E-mail discussion group on the history of cartography hosted by the Faculty of Geosciences, University of Utrecht. The statements and opinions expressed in this message are those of the author and do not necessarily reflect those of the University of Utrecht. The University of Utrecht does not take any responsibility for the views of the author. List Information: http://www.maphist.nl Maphist mailing list [email protected] http://mailman.geo.uu.nl/mailman/listinfo/maphist
