Summary of Lidar Formats

At present, there are three sets of LIDAR data that are being utilized in this project.

1) FORMAT 1

The first is the LIDAR DEM files download from the ATLAS site.  This is in a USGS ASCII DEM format.  Rather than working with this directly, we convert this, via GRASS GIS, into a different format.  This forms the second format.

2) FORMAT 2

The second is the GRASS GIS ASCII GRID format (2D raster format found HERE).

The format is:

north: n // Northern boundary
south: s // Southern boundary
east: e // eastern boundary
west: w // wester boundary
rows: A // A is number of rows
cols: B // B is number of columns
v11 v12 .... v1B // first row. vXY is a height value.
.
.
.
.
vA1 vA2 .... vAB // last row.  vXY is a height value.

NOTE:  In the real file, no comments (// whatever) are allowed.

The rows are the northing (north to south) and the columns are west to east.

The vXY values are in feet.  The coordinate information is in meters.  v11 represents the NW boundary point.  It should be noted that this is NOT the CENTER of the cell.  Rather, it is the most northern and western part of the cell.

An NULL value, currently, is being represented by -32747.

3) Format 3

The third format is the Raw LIDAR points.  The format is

easting, northing,height
easting, northing,height
easting, northing,height

Each row is one data point.  The easting is the value corresponding to the east-west value and the northing is the value corresponding to to north-south.  The easting and northing are in meters.  The height is in feet.