Data Preparation

MicroLevel operates on ER Mapper (.ers) grids only. 

MicroLevel requires that the elongate anomalies to be removed must be along either the grid rows or columns. Where a survey's flight lines were not flown along the N-S or E-W  directions, the Rotate Grid utility (Utilities|Rotate Grid) can be used to rotate the grid so that the anomalies align with either the grid rows or columns. After decorrugation, the rotation can be undone using the Unrotate utility (Utilities|Unrotate Grid).

IMPORTANT NOTE: MicroLevel does not rotate grids on the fly for the purpose of grid display. The grid images in the display panels are displayed assuming a rotation of zero. Users can still digitise polygons off rotated grids, and use these polygons in the decorrugation process in the normal way. This is so even though the polygon coordinates are not corrected for the grid rotation. Since both the grid and the polygon share the same coordinate system (both are rotated), the polygon will correctly exclude areas from the decorrugation. 

Directory Structure

The very first thing a user is required to do after launching MicroLevel is to specify the "Working Directory". This cannot be set via a control file. The grids to be levelled are then assumed to reside in a sub-directory of the Working Directory. The Working Directory will also contain files created by MicroLevel such as Program Control Files and Polygon Files. MicroLevel always reads and writes grids to the same directory - i.e. grids are written to the directory that the input grids are read from.