ANSI-C program: d2pt.c
NAME
d2pt - raster to vector format conversion (extract values from a
2-D data file at specified point locations)
SYNOPSIS
d2pt <f_in> <width> <plist>
<rlks> <azlks> <pdata> <rec_num>
<type>
| <f_in> | (input) 2-D image data file (various types supported) |
| <width> | (input) image width (ignored if input is a raster image) |
| <plist> | (input) point list for sampling (int) |
| < rlks> | (input) range looks of input data relative to point list |
| <azlks> | (input) azimuth looks of input data relative to point list |
| <pdata> | (output) point data stack (same type as f_in) |
| <rec_num> | record number in output point data stack (starting with 1) |
| <type> | data type (0:fcomplex 1:scomplex 2:float 3:int 4:short 5:byte 6:SUN/BMP raster) |
EXAMPLE
d2pt 19920422.rslc 4912 plist 1 1 pSLC 4
1
Extracts complex SLC values (scomplex) at the point list (plist) coordinates from the registered SLC 19920422.rslc and writes the values as record number 4 to the output point data stack pSLC (scomplex). The geometry of the SLC data file is 4912 pixels wide. The number of looks in range and azimuth of the SLC data is 1 in range and 1 in azimuth.
d2pt ave20.rmli 2456 plist 2 10 pmli 4 2Extracts values (float) at the point list (testsite.plist) coordinates from the averaged backscatter intensity image (ave20.rmli) and writes the values as record number 1 to the output data stack pmli(float), a stack with just a single record. The number of range looks is 2 and azimuth looks, 10. The data format is float.
INSTALLATION
Source code d2pt.c in ./IPTA/src, executable version data2pt in
./IPTA/bin
DESCRIPTION
The use of point data stacks is an important element of the IPTA.
Registered SLC data, and data in map coordinates sampled at point
locations are stored in data stacks with each record
corresponding to the values from a single data layer. d2pt is a
general sampling program that supports sampling input data in
natural radar or map coordinates. The number of looks in
range and azimuth refer to a scaling factors between coordinates
in the plist and the coordinates of the raster data. The rlks
parameter refers to the across direction and the azlks parameter
to the y coordinate or equivalently the line number. It is
assummed that the input data are smaller or the the same size as
the reference geomentry where the coordinates of the points is
specified.
The extracted values (in binary vector data format) are
written to the point data stack at the indicated record number.
The record numbers start with 1. The number of records
corresponds to the highest record number. Stacks with just a
single record are used in the case of data files as the terrain
height. If a new stack name is indicated the stack is created.
Indicating a record number larger than the highest record number
of the indicated stack results in an increase of the stack
size.
Different data types (fcomplex, scomplex, float, int, short,
byte, SUN/BMP raster) are supported. The data type of the input
2-D data and the output point data stack are assumed to be
identical.
SEE ALSO
data2pt.c