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'Batch' access to LAS data

Question:

How can I get 'batch' access to LAS data, i.e. without going through the user interface?

Explanation:

If a Live Access Server has a lot of useful data, particularly if it is regularly updated, it won't be long before people want to automatically harvest the data. Although we've tried to make the LAS user interface as friendly as possible, interactions with it cannot be automated. To address the need for 'batch' access to LAS data we have written a couple of scripts which can interact with LAS, bypassing the user interface.

Solution:

W currently provide two scripts:

• ls.pl queries the server for dataset, variable and axis information
• lasget.pl requests data from the server.

You can find out how to use the scripts by running them with no arguments:

> ls.pl
Usage: ls.pl [-l] [-s separator] url [dataset] [variable]
       -l              displays descriptive name for a dataset or variable
                       and the type, units, and bounds of an axis.
       -s separator    delimit fields with separator
Example: ls.pl http://ferret.pmel.noaa.gov/las-bin/LASserver.pl


> lasget.pl
Usage: lasget.pl [-x xrange ] [-y yrange] [-z zrange] 
                 [-t trange] [-f format] [-o file] 
                 url dataset variable
       -x xrange      x range of data (-120, -120:80)
       -y yrange      y range of data (0, 0:90)
       -z zrange      z range of data (0, 0:20)
       -t trange      time range of data (1992-Dec-10, 1992-Jan-1:1992-Dec-1)
       -o file        output file. Defaults to stdout
       -f format      output format asc|cdf|txt|ps|html
       url            URL of LAS server
       dataset        name of dataset
       variable       name of variable

Note that these perl scripts require some additional perl modules which may not have been previously installed on your system.

use LWP::UserAgent;
use URI::URL;
use URI::Escape;
use Getopt::Long;
use Getopt::Std;

You can pick up these modules by using the Perl CPAN module; type perldoc CPAN for more info.

Jonathan Callahan: Jonathan.S.Callahan@noaa.gov
Last modified: July 24, 2002