----------------------------Original message----------------------------
I have the DMA MIL SPEC MIL-H-89201A for all HAC products.  Paragraph 3.3.1
states that horizontal accuracy is 1.0 mm at chart scale.  Hopes this helps.
 
 
 
> -----Original Message-----
> From: Courtney Schumacher [SMTP:[log in to unmask]]
> Sent: Tuesday, March 17, 1998 1:02 PM
> To:   [log in to unmask]
> Subject:      DMA standards and accuracy
>
> ----------------------------Original message----------------------------
> 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
>
> --
> ---------------------------------------------------------------------
> Courtney Schumacher           INTERNET: [log in to unmask]
> Dept of Atmospheric Sciences
> Box 351640                    TEL: (206)685-1073
> University of Washington
> Seattle, WA  98195-1640
> ---------------------------------------------------------------------