The LIDAR format
contains binary data consisting of a header
block, variable length records, and point data. All
data is in little-endian format. The header block
comprises a public block. The public
block contains
generic data such as point numbers and coordinate
bounds. It lists items along with their format, size, and specifies whether the item is required or not.
- X, Y, and Z scale factors
- The scale
factor fields contain a
double floating point value that is used to scale the
corresponding X, Y, and Z long values within
the point records. The corresponding X, Y, and Z
scale factor must be multiplied by the X, Y, or Z
point record value to get the actual X, Y, or Z
coordinate. For example, if the X, Y, and Z coordinates
are intended to have two decimal point values,
then each scale factor will contain the number 0.01.
- X, Y, and Z offset
- The offset
fields should be used to set the
overall offset for the point records. In general
these numbers will be zero, but in specific cases
the resolution of the point data may not be large
enough for a given projection system. However, it should always be
assumed that these
numbers are used. Therefore, to scale a given X from the point record, take
the point record X multiplied
by the X scale factor, and then add the X offset.
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