Publication Data Updates (PDU)

 

 

What is a PDU?

Publication Data Updates (PDU) are small binary patch files (generally < 2.5 Mb) which, when applied to the current baseline of a Digital Nautical Publication (DNP), will bring that publication up-to-date with all outstanding corrections. These corrections include, but are not limited to, U.S. Notice to Mariner changes (textual and graphic) as well as compilation analysis changes that previously only appeared in the next new edition. In short, all updated information as of the date of the PDU is included. With PDU, Digital Nautical Publications will contain more extensive and timely maritime safety information for the use of our customers.

Starting 1 October 2002, all navigation publication new editions will be produced in digital format only. All publications are available on the Digital Nautical Publications – Quarterly Update or on the Maritime Safety Web site. Publication Data Updates are available for Digital Nautical Publications in a WinZip archive file, located on the same Web page where the publication files are accessed.  There are two possible types of updates available; sequential or cumulative.

·        Sequential updates apply to the entire publication and must be applied in date order (i.e., oldest to newest).

·        Cumulative updates are larger files that include all the sequential updates and allow the user the option of downloading and installing all sequential updates at once.

 

IMPORTANT NOTES:

  • NGA's transition away from hardcopy publications in favor of digital medium will be a phased-in process. Current hardcopy publications will remain in effect until replaced by a new edition DNP and will continue to be updated via the U.S. Notice to Mariners. PDU will only be generated for those publications generated as DNP (new editions after 1 Oct 2002).
  • PDU CANNOT be applied to previous (old) editions of a Digital Nautical Publication. You will receive an error message stating, in part, that "...a file of the same name was found. No update done..." when trying to apply the update to a previous edition. The publication will not be updated.
  • For sequential PDU's, each update will build on the previous one. This ensures that the updates remain small while ensuring the most comprehensive and up-to-date product for our customers.
  • Effective 1 July 2010, Publication Data Updates (PDU) patch files will no longer be provided to customers in an executable file format (".exe") via the PDU Subscription Service, or as a download from the Maritime Safety Web site. PDU patch files will be provided in their native file format (".rtp" file) only, and will require these additional PDU support files in order to be properly applied.

 

System Requirements:

Any personal computer (PC) running Windows 9X, Windows ME, Windows 2000, Windows NT, or Windows XP.

How is it used?

Download Instructions:

  • On the Maritime Safety Web site, navigate to the "Publications" section and locate the desired publication to check for updates.
  • Some publications have the updates on the same page as the publication; in the case of Sailing Directions, choose the publication from the "Digital Updates" drop-down menu. If the desired Sailing Directions publication is not listed in the "Digital Updates" drop-down menu, then there are no updates for that publication.
  • Right-click on the update to download.
  • Select "Save Target As" (Microsoft Internet Explorer) or "Save Link As" (Mozilla Firefox).
  • Specify the location to save the update on the computer's local hard disk drive.
  • Select "Save."
  • The file will be downloaded to the computer's local hard disk drive.
  • Unzip the ".rtp" patch file using a program such as WinZip, PKUNZIP, etc.

Applying the Update:

  • Extract and save the required PDU support files to the computer's local hard disk drive.
  • The PDU tutorial includes step-by-step instructions, with screenshots, on how to apply the PDU patch using the ".rtp" file format.

Verifying the Update:

  • Click on the "Start" button.
  • Navigate to Programs > NGA_Data > Sailing Directions > PUB ### > PUB ### (pdf file).
  • After the PDF file opens, a JavaScript window will appear stating "Publication ### is correct through PDU # - ## ### 20##." Click "OK" to acknowledge and close the window.
  • To locate where changes occurred throughout the publication, a change bar symbol ( | ) was added to the left of the data to indicate a change has taken place. Note: If information was removed from the file, such as an entire paragraph, there may be no indication of that change.

Subscribe to Publication Data Updates (PDU) via E-mail

 

To accommodate customers who experience difficulty accessing the World Wide Web, NGA provides a Subscription Service whereby Publications Data Updates (PDU) are delivered via e-mail message to the requesting address. In addition, subscribers will receive an e-mail notification when a publication new edition is released.

 

Currently, only those customers who have the Digital Nautical Publications - Quarterly Update can update the NOS Coast Pilots and NGA List of Lights publications via the PDU e-mail Subscription Service. The PDU's for these publications will be delivered to the requesting address twice between each quarter. The first PDU will be a sequential update; the second PDU will be a cumulative update. These publications should be uninstalled upon receiving the next Digital Nautical Publications - Quarterly Update product, as the update process will start over. When a new edition to a NOS Coast Pilot or NGA List of Lights is published between quarters, no PDU will be delivered and the new edition will be available on the next Quarterly product.

 

Many networks and e-mail applications have restrictions on file sizes for e-mail attachments. In order to ensure all PDU files are received, the limit on file sizes for the receiving account should be changed to 4 Mb. Contact your system's administrator or help desk for more assistance.

 

PDU files transmitted for Sailing Directions publications are also posted in the "Publications" section of the Maritime Safety Web site.

 

In order to subscribe, customers must visit the PDU Subscription page. A confirmation e-mail will be sent to the requesting e-mail address from NGA's Subscription Service provider. Instructions to unsubscribe from the Service are included in each subscription e-mail.

 

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