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Hello,
 
I sent the below message to NIMA who pointed me toward NOAA and from
whom I haven't heard yet. The map librarian at the University of
Washington suggested I direct my questions toward this listserve.
 
I'm curious about DMA map accuracy in the central/western, tropical
Pacific.  A meteorological research project that my group is involved
with is underway in the Marshall Islands. We have 17 rain gauges
between 7-9.5 N and 166-169 E. A GPS receiver was recently sent out to
get exact lat/lons of the gauges, however, the GPS unit at times
disagreed with DMA nautical maps of the area (map numbers: 81030,
81715, 81723, 81557, 81737). The largest disagreement was almost 20 km
but in general the discrepancies were on the order of a km. What is
the DMA standard for island locations on their nautical maps? Are the
locations accurate to within a km? I understand that there could have
been errors in the GPS readings but I'm trying to bound the possible
error of the DMA maps. Any information or references would be
appreciated!
 
Thanks,
Courtney Schumacher
 
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Courtney Schumacher           INTERNET: <a href="/scripts/wa-UGA.exe?LOGON=A3%3D9803%26L%3DMAPS-L%26E%3D7bit7BIT%26P%3D171766%26B%3D--%26T%3Dtext%252FplainTEXT%252FPLAIN%3B%2520charset%3DUS-ASCII%26pending%3D" target="_parent" >[log in to unmask]</a>
Dept of Atmospheric Sciences
Box 351640                    TEL: (206)685-1073
University of Washington
Seattle, WA  98195-1640
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