Accessing DAO Data from Scripts

DAO files can be retrieved directly from your scripts by using a URL's of the form "http://www.cadc.hia.nrc.gc.ca/data/pub". If files are proprietary this URL is redirected to one of the form "http://www.cadc.hia.nrc.gc.ca/data/auth" and you will be prompted for your CADC user ID and password if you use such a URL from a web browser. Alternatively, you will need to include authentication in a curl command. Note that DAO files are stored in gzipped format so this URL will return a compressed file.

For example, below is a simple PERL script that retrieves three public files from the DAO Science Archive:

  #!/usr/bin/env perl 
  use strict;

  my @files    = ( "dao_c122_2010_012345", "dao_c182_2010_023456", "dao_20101215_skycam0" );
  my $baseUrl  = "http://www.cadc.hia.nrc.gc.ca/data/pub";
  my ( $fileId );

  foreach $fileId (@files)
  {
    `curl --location-trusted -g -o $fileId.fits.gz "$baseUrl/DAO/$fileId"`;
  }

  exit();

You can also retrieve proprietary files (if you have authorization!) by modifying this basic script as shown below. Note the use of your CADC user account information.

  #!/usr/bin/env perl 
  use strict;

  my $baseUrl       = "http://www.cadc.hia.nrc.gc.ca/data/pub";
  my $cadcUserId    = "dbohlender";  # Your CADC user ID
  my $passWord      = "????????";    # Your CADC account password
  my @files         = ( "dao_c122_2010_012345", "dao_c182_2010_023456", "dao_20101215_skycam0" );
  my ( $fileId );

  foreach $fileId (@files)
  {
    `curl --location-trusted -g -o $fileId.fits.gz -u $cadcUserId:$passWord "$baseUrl/DAO/$fileId"`;
  }

  exit();
  

You can find more details and other examples of "getData" usage, including retrieval of FITS header content, here.