
[Federal Register Volume 79, Number 43 (Wednesday, March 5, 2014)]
[Notices]
[Pages 12563-12564]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-04856]


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DEPARTMENT OF TRANSPORTATION


Global Positioning System Pre-Operational Civil Navigation; 
Message Continuous Broadcast

AGENCY: Office of the Assistant Secretary for Research and Technology, 
Department of Transportation.

ACTION: Notice; request for public comments.

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SUMMARY: The purpose of this notice is to seek comment from the public 
and industry regarding plans by the United States Air Force to 
broadcast pre-operational L2C and L5 civil navigation (CNAV) messages 
from certain Global Positioning System (GPS) satellites beginning in 
April 2014. These messages will be formatted in accordance with 
Interface Specifications IS-GPS-200G and IS-GPS-705C, each dated 31 Jan 
2013. However, a pre-operational signal means the availability and 
other characteristics of the broadcast signal may not comply with all 
requirements of the relevant Interface Specifications and should be 
employed at the users' own risk.
    The Department of Transportation seeks comments on: (a) The 
benefits, risks, or issues to users from this plan, including comments 
on the appropriate timeline for broadcasting pre-operational CNAV 
messages. Comments are requested from industry on: (b) the receiver 
development benefits and other intended uses of pre-operational 
signals, and (c) the benefits and potential impacts to users of 
continuous pre-operational CNAV messages with L2C and L5 signals set 
healthy.

DATES: Submit comments on or before April 4, 2014.

ADDRESSES: You may submit comments identified by docket number [DOT-
OST-2014-0028] using any one of the following methods:
    (1) Federal eRulemaking Portal: http://www.regulations.gov.
    (2) Fax: 202-493-2251.
    (3) Mail: Docket Management Facility (M-30), U.S. Department of 
Transportation, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590-0001.
    (4) Hand delivery: Same as mail address above, between 9 a.m. and 5 
p.m., Monday through Friday, except Federal holidays. The telephone 
number is 202-366-9329.
    To avoid duplication, please use only one of these four methods. 
See the ``Public Participation'' portion of the SUPPLEMENTARY 
INFORMATION section below for instructions on submitting comments.
    Confidential Business Information: If you wish to submit any 
information under a claim of confidentiality, you should submit three 
copies of your complete submission, including the information you claim 
to be confidential business information, to the address given below 
under FOR FURTHER INFORMATION CONTACT. In addition, you should submit a 
copy from which you have deleted the claimed confidential business 
information to the docket. When you send a comment containing 
information identified as confidential business information, you should 
include a cover letter setting forth the reasons you believe the 
information qualifies as ``confidential business information''. (49 CFR 
7.17)

FOR FURTHER INFORMATION CONTACT: If you have questions on this notice 
or would like to schedule a discussion, contact Karen L. Van Dyke, 
Office of the Assistant Secretary for Research and Technology 
Administration, Director Positioning, Navigation, and Timing and 
Spectrum Management, telephone 202-366-3180 or email 
karen.vandyke@dot.gov. If you have questions on viewing or submitting 
material to the docket, call Barbara Hairston, Docket Operations, 
telephone 202-366-9826.

SUPPLEMENTARY INFORMATION:

Background and Purpose

    The United States Government is currently adding new civil signals 
to the GPS constellation, including L2C and L5. The Commander of the 
United States Air Force Space Command directed that, beginning in April 
2014, GPS satellites will broadcast navigation messages on the L2C and 
L5 signals to facilitate development of compatible user equipment and 
CNAV operational procedures. This extended pre-operational continuous 
broadcast is the next phase of development of a new capability based on 
the testing done in June 2013, per 78 Federal Register Notice 17185, 
March 20, 2013. This broadcast message capability is to be implemented 
using current GPS ground control capabilities in advance of more 
automated capabilities to become operational with the Next Generation 
GPS Operational Control System, called OCX.
    The CNAV message broadcasts planned to begin in April 2014 will be

[[Page 12564]]

implemented on all operational GPS satellites capable of transmitting 
the L2C and L5 signals. Currently, seven GPS IIR-M satellites broadcast 
L2C and four GPS IIF satellites broadcast L2C and L5. On average, users 
may expect at least one L2C-broadcasting satellite to be in view at all 
times. The CNAV message content will include Broadcast Message Types 
(MT) 10, 11, 30, and 33 (as defined in IS-GPS-200G and IS-GPS-705C, see 
http://www.gps.gov/technical/icwg/) in lieu of the currently 
transmitted MT-0. The Air Force intends to broadcast L2C and L5 
messages with the health bits set healthy, as was the case during the 
June 2013 test. The CNAV data uploads will be integrated into current 
operations, but initially the uploads to each appropriate satellite 
will occur only twice per week. In December 2014, CNAV uploads are 
planned to be at the normal rate of once per day for each appropriate 
satellite. Consequently, users should expect L2C and L5 signals with 
CNAV messages to provide increased user range error compared to legacy 
civil signals between April and December 2014. After December 2014, the 
accuracy of the L2C and L5 signals with CNAV messages is expected to 
meet or exceed that of legacy signals. Future tests and implementation 
of the remaining CNAV message types will be announced under separate 
Federal Register Notices.
    The pre-operational CNAV messages are being made available for user 
familiarization and for equipment development. They should not be 
considered operational pending availability of OCX monitoring and 
control capabilities, and therefore they should not be used for safety-
of-life or other critical purposes. Caveats indicating ``Developmental 
Signal-in-Space, non-operational'' will be included in Notice Advisory 
to NAVSTAR Users (NANUs).
    The Department of Transportation seeks comments on benefits, risks, 
or issues to users from this plan, including comments on the 
appropriate timeline for implementing the plan. Comments are requested 
from industry on the receiver development benefits and other intended 
uses of pre-operational signals. Comments are also requested on the 
benefits and potential impacts to users of continuous pre-operational 
CNAV broadcast with signals set healthy.

Public Participation

    You may submit comments and related material regarding this 
proposed plan. All comments received will be posted, without change, to 
http://www.regulations.gov and will include any personal information 
you have provided.
    Submitting comments: If you submit a comment, please include the 
docket number for this notice (DOT-OST-2014-0028) and provide a reason 
for each suggestion or recommendation. You may submit your comments and 
material online or by fax, mail or hand delivery, but please use only 
one of these means. We recommend that you include your name and a 
mailing address, an email address, or a telephone number in the body of 
your document so that we can contact you if we have questions regarding 
your submission.
    To submit your comment online, go to http://www.regulations.gov and 
use ``DOT-OST-2014-0028'' as your search term. Locate this notice in 
the results and click the corresponding ``Comment Now'' box to submit 
your comment. If you submit your comments by mail or hand delivery, 
submit them in an unbound format, no larger than 8\1/2\ by 11 inches, 
suitable for copying and electronic filing. If you submit comments by 
mail and would like to know that they reached the Facility, please 
enclose a stamped, self-addressed postcard or envelope.
    We will consider all comments and material received during the 
comment period.
    Viewing the comments: To view comments, as well as documents 
mentioned in this notice as being available in the docket, go to http://www.regulations.gov and use ``DOT-OST-2014-0028'' as your search term. 
Use the filters on the left side of the page to highlight ``Public 
Submissions'' or other document types. If you do not have access to the 
Internet, you may view the docket online by visiting the Docket 
Management Facility in Room W12-140 on the ground floor of the 
Department of Transportation West Building, 1200 New Jersey Avenue SE., 
Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, 
except Federal holidays.
    Privacy Act: Anyone can search the electronic form of comments 
received into any of our dockets by the name of the individual 
submitting the comment (or signing the comment, if submitted on behalf 
of an association, business, labor union, etc.). You may review a 
Privacy Act system of records notice regarding our public dockets in 
the January 17, 2008 issue of the Federal Register (73 FR 3316).

Gregory D. Winfree,
Assistant Secretary, Office of the Assistant Secretary for Research and 
Technology.
[FR Doc. 2014-04856 Filed 3-4-14; 8:45 am]
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