Feather And Merge Grids
Feather And Merge Grids feathers the grids in the input directory onto the merged grid. Residual differences along the grid edges are removed by propagating them into the overlapping grids by distances proportional to their wavelength (up to a maximum of featherDistance). This produces a seamless join. Feathering is usually reserved for the final merge as it is somewhat slower that Merge.
Grids are feathered/merged in a reverse-priority order – the lowest priority-order grid is written to the merged grid first, with higher-priority grids written on top. There is no limit on the size of the first grid (the lowest-priority grid) interpolated onto the merged grid. Subsequent higher-priority grids must be able to fit into computer memory.
Quick Link: See Using GridMerge With Large Grids for an explanation of memory management in GridMerge.
The aliases and parameters that must be set for this process (via the Set Aliases and Parameters menu) are shown in the table below.
|
Control File Keyword |
Type |
Description |
|
inputGridDirectoryFeather |
string |
The input grid directory. |
|
outputGridDirectoryFeather |
string |
The output grid directory. |
|
outputGridFeather |
string |
The output grid name. |
|
priorityOrderFileFeather |
string |
The grid Priority Order File. |
|
cellSizeFeather |
string |
The desired cell size (degrees or metres, depending on the projection of the input grids). |
|
featherDistance |
integer |
The feather distance in metres. Overlap differences are feathered this distance into the grids. |
|
topLeftXFeather* |
float |
The top-left X coordinate of the output grid (this is also the X origin). |
|
topLeftYFeather* |
float |
The top-left Y coordinate of the output grid (this is also the Y origin). |
|
bottomRightXFeather* |
float |
The bottom-right X coordinate of the output grid. |
|
bottomRightYFeather* |
float |
The bottom-right Y coordinate of the output grid. |
* optional. If left unspecified, GridMerge will calculate the grid extents from the input grids.