DDR Integer FieldsRefer to the LAS 7.1 Programmer's Guide for the manner in which each LAS module updates the DDR.
nl Number of lines in image
ns Number of samples in image
nbands Number of bands in image
dtype Data type of samples:
=1: unsigned char
=2: short
=3: long
=4: float
master_line Line relative to master image
master_sample Sample relative to master image
valid[0] => projection code flag
valid[1] => zone code flag
valid[2] => datum code flag
valid[3] => projection coefficients
valid[4] => ground units
valid[5] => ground distance
valid[6] => corner coordinates
valid[7] => line/sample increments
NOTE: The flags can have the value of:
=0: INVALID
=1: VALID
=2: UNKNOWN
proj_code GCTP projection code
zone_code UTM or State Plane zone
datum_code Code for the datum/ellipsoid. Represents ellipsoid ONLY if less than 100.
DDR Character Fields
system[12] Computer system data is on
proj_units[12] Projection units(GCTP units+other)
last_used_date[12] Last access date. NOTE: All ddr dates are stored as "ddmmm-yy". For example, a date of December 31, 1986 is stored as: "31dec86" with month in lower case.
last_used_time[12] Last access time. NOTE: All ddr times are stored using a twenty- four hour clock. Seconds are separated by a colon. Example: 1:05:55 pm is stored as 1305:55
DDR Double Precision Fields
proj_coef[15] Projection parameters. Refer to GCTP documentation for field definitions
upleft[2] Corner coordinates entered in latitude/longitude
loleft[2] or projection coordinates (y,x) in northing/
upright[2] easting order
loright[2]
pdist_y Projection distance/pixel (y)
pdist_x Projection distance/pixel (x)
line_inc Line increment for sampling
sample_inc Sample increment for sampling. NOTE: The line/sample increments are the values applied to the original image to obtain this image. If resampling or subsampling was not applied, the value contained in these fields is 1.0
Band DDR Integer Fields
bandno Band number
valid Validity flag for min/max
=0: INVALID
=1: VALID
=2: BOUNDED
Band DDR Double Precision Fields
minval Minimum intensity value
maxval Maximum intensity value
Band DDR Character Fields
source[32] Source of data
instrument[32] Type of sensor
direction[64] Direction of the capture process
date[10] Capture date (See date format previously listed)
time[8] Capture time (See time format previously listed)