[Xastir] Re: Bounding boxes [Re: USGS maps no longer free]

[Tyler Allison]

> On Mon, Oct 06, 2003 at 07:09:55PM -0600, a Mr. Richard Feyler of Fort
> Lee, New Jersey <russo at bogoflux.losalamos.nm.us> writes 'Dear Rosanne
> Rosannadanna':
>>
>> But I'm concerned about the actual values in Tyler's examples --- USGS
>> maps are usually defined by very simple lat/lons --- for example, the
>> 7.5-minute quads are aligned so that they have west boundaries of,
>> say, 106d-105d52m30s for one map, 105d52m30s-105d45m for the next one
>> to the east, 105d45m-105d37m30s for the next, etc.  That the
>> re-projected corner points don't map to neat values concerns me ---
>> perhaps they were projected back using the wrong datum?  The
>> difference seems too great for that, though.
>
> And now that I think about it, the data listed by listgeo are probably the
> corner coordinates of the entire image, not the data for the map collar
> ---
> therefore making their use in an FGD file pointless.
>

So if the entire geotiff file is the topographic data, thus no stripping
required, and the ENTIRE listgeo output from that tif file is:

------------------------------
Geotiff_Information:
   Version: 1
   Key_Revision: 1.0
   Tagged_Information:
      ModelTiepointTag (2,3):
         0                0                0
         5205005.7        4299352.26       0
      ModelPixelScaleTag (1,3):
         6.6667           6.6667           0
      End_Of_Tags.
   Keyed_Information:
      End_Of_Keys.
   End_Of_Geotiff.


Corner Coordinates:
Upper Left    (5205005.699,4299352.261)
Lower Left    (5205005.699,4253418.698)
Upper Right   (5241025.879,4299352.261)
Lower Right   (5241025.879,4253418.698)
Center        (5223015.789,4276385.479)
---------------

What would the FGD file need to be?

The documentation for the file (at the Kentucky GIS website) says it is in
NAD83 format in zone 16 with:
South = 39.000
West = -84.75
North = 39.125
East = -84.625

I try plugging in the Upper Left/etc coordinates into Xastir or even cs2cs
and they look NOTHING like the ones provided in the documentation (eg:
39.000) In fact Xastir will not accept "16N 5205005 4299352" as a valid
coordinate. If I drop one of the digits from the '5205005' number it
calculates. Maybe there is something wrong with the coordinates in the
geotiff file?

If I use the coords provided above (eg: 39.000) in the FGD, file Xastir
fails to load the image at debug level 16 with an error:

NW neat-line corner = -84.750000        39.125000
Problem in translating
NE neat-line corner = -84.625000        39.125000
Problem in translating
SW neat-line corner = -84.750000        39.000000
Problem in translating
SE neat-line corner = -84.625000        39.000000
Problem in translating

I realize that the geotiff file is using the Kentucky Single State Plane
Zone (whatever that is) but I figured I could at least get the image to
display in Xastir...even if it was not correctly positioned.

For reference...the zip containing the geotiff file is located here:
ftp://kymartian.ky.gov/krgs/B40.zip
(note: the tif is compressed in a format Xastir doesnt like so I had to
geotifcp -c none the file)

Metadata information here:
http://kymartian.ky.gov/krgmaps/KRG_Metadata.pdf

Any help on getting this to work would be appreciated. Once I/we figure
this out I'll be able to write up a HOWTO for getting the Kentucky (and
possibly Ohio) geotiff files to work in Xastir.

-Tyler