Bug #622: redundancy in eml-physical/binaryRaster - EML - Ecoinformatics Redmine

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Bug #622

closed

redundancy in eml-physical/binaryRaster

Added by Peter McCartney about 22 years ago. Updated about 22 years ago.

Status:

Resolved

Priority:

Normal

Assignee:

Matt Jones

Category:

eml - general bugs

Target version:

EML2.0.0rc2

Start date:

10/04/2002

Due date:

% Done:

Estimated time:

Bugzilla-Id:

622

Description

the following elements are redundant and could be deleted.

binaryRaster/nbands is redundant with spatialRaster/numberOfBands
binaryRaster/ncols is redundant with spatialRaster/columns
binaryRaster/nrows is redundant with spatialRaster/rows
binaryRaster/xdim is redundant with spatialRaster/cellsizexdirectioin
binaryRaster/ydim is redundant with spatialRaster/cellsizeYdirectioin

binaryRaster/ulxmap and ulymap are not redundant, but im not sure are adequate.
the purpose of these is to tell you how to relate the cells to the coordinate
system which is only needed if the file is shipped in a format that isnt aready
georeferenced in its header. Given we know the cell dimensions from spatial
raster, these two values will let us place the grid except that we dont know if
the point refers to the upper left corner of the cell or its center. Erdas, for
example has you specifiy this when registering grids. others have you specify
this as a boundary extent and indicate whether the points are outer courners or
center points of the cell. In the example dan pulled from esri, this is just
one way that they do it and they clearly are makein an assumption about where
in that upper left cell the reference point lies.

the simplest fix here is to add one field called ulRefPoint to indicate where
in the cell the coordinate referes to. give it a domain of upperLeft,
upperRight, center, lowerLeft, lowerRight.

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Updated by Peter McCartney about 22 years ago

mind you thisis not a perfect fix. it only works for grids that are
rectified..that is, their columns and rows are aligned with the coordinate
system referred to in spref. if not, then you really need to have two points to
correctly position the grid (more if the grid has to be rubbersheeted).
Bombproof is to provide the option to give coordinates for all four corners -
e.g. :

<xs:element name =refPoint minoccurs=1 maxoccurs=4>
<xs:element name = xcoord type=float>
<xs:element name = ycoord type=float>
<xs:element name = corner type=string>
<xs:enumeration value=upperLeft>
<xs:enumeration value=upperRight>
<xs:enumeration value=lowerLeft>
<xs:enumeration value=lowerRight>

&lt;xs:element name = positonInCell type=float&gt;
     &lt;xs:enumeration value=upperLeft&gt;
     &lt;xs:enumeration value=upperRight&gt;
     &lt;xs:enumeration value=lowerLeft&gt;
     &lt;xs:enumeration value=lowerRight&gt;
     &lt;xs:enumeration value=center&gt;

<xs:element>

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Updated by Peter McCartney about 22 years ago

nbands, ncols,nrows,ydim,xdim were all removed from the binaryRaster format
element in eml-physical because of redundancy with spatialRaster

ulxmap and ulymap were also removed in favor of providing a more structured
format within spatial raster for providing information on how to locate a grid
on a coordinate system.

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