TAG: CNAV

GPS CNAV Debate, and GNSS Interoperability Moves Forward

March 27, 2014By

The most modernized GPS satellites on orbit will broadcast a new civil navigation message (CNAV) on the L2C and L5 signals in April. That's the plan, at least. An update on the CNAV debate in the United States. Also, summaries of key presentations from the international committee charged with inter-GNSS compatibility and interoperability. read more

ANGELS, GSSAP, CNAV, and GPS: Guidance From Above

March 13, 2014By
A still from the movie Gravity, where space real estate feels really small. (credit: Warner Bros. Pictures)

Wow, what a bevy of acronyms. If you already know what they mean, great. If you don’t, just hang in and all will be made clear. E. L. Doctorow once wrote, “Writing is a socially acceptable form of schizophrenia.” Now, I am not sure how I feel about that or how my daughter who is a practicing Clinical Psychologist (PsyD) would interpret... read more

This article is tagged with , and posted in Defense, Opinions

PNT Advisory Board Hears Air Force CNAV Plan

March 12, 2014By
PNTAdvBd-O

The U.S. National Space-Based Positioning, Navigation, and Timing (PNT) Advisory Board has published the minutes of its December 4–5, 2013, meeting, opening with a quote from Albert Einstein, “We cannot solve our problems with the same thinking we used when we created them,” courtesy of Board Chair Dr. James Schlesinger. Among many other topics addressed, the Board heard a report... read more

Comment Period on Pre-Operational CNAV Message Opens

March 5, 2014By
Carrier-to-noise ratio of L5 signals, measured on June 19, 2013, by  Zheng Yao and colleagues at Tsinghua University, China. Signals were analyzed from three GPS satellites whose PRN numbers are 1, 24, 25, and one QZSS satellites with the PRN of 193 at time of acquisition.

A Federal Register Notice has been published allowing for a 30-day comment period on the proposed CNAV message on L2C and L5. The notice seeks comment from the public and industry regarding plans by the U.S. Air Force to broadcast pre-operational L2C and L5 civil  navigation (CNAV) messages from certain GPS satellites beginning in April. The Department of Transportation is... read more

This article is tagged with , , and posted in Featured Stories, GNSS, Latest News

DoT Disses DoD’s GPS Chops

January 9, 2014By

The departing Deputy Secretary of Transportation, John Porcari, wrote a letter in the closing days of 2013 opposing the U.S. Air Force’s announced plans to begin broadcasting Civil Navigation (CNAV) message-populated L2C and L5 signals as early as April 2014. Military personnel are incensed over what they see as Porcari’s impugning, when not ignoring, the Air Force 35-year track record... read more

The System: Two More Threes for Space

January 1, 2014By

A December 12 contract modification provided Air Force funding to Lockheed Martin to complete the fifth and sixth GPS III space vehicles (SV 05-06). Lockheeed originally received funding to procure long-lead parts for satellites five through eight (SV 05-08) in February 2013. read more

Air Force Directs Early Civil Navigation (CNAV) Message-Populated L2C and L5 Signals

December 17, 2013By

The U.S. Air Force is directing transmission of continuous CNAV message-populated L2C and L5 signals starting in April 2014. The move is designed to help development of user equipment compatible with the civil signals. Full text of the CNAV memo appears below. MEMORANDUM FOR THE NATIONAL COORDINATION OFFICE FOR SPACE BASED POSITIONING, NAVIGATION AND TIMING ATTENTION: DR. JAN BRECHT-CLARK FROM:... read more

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The System: IRNSS Success, GLONASS Bellyflop

August 1, 2013By

IRNSS Success The Indian Regional Navigation Satellite System (IRNSS) successfully launched its first satellite on July 1 from the Satish Dhawan Space Centre at Sriharikota spaceport on the Bay of Bengal. An Indian-built Polar Satellite Launch Vehicle PSLV-C22, XL version, carried the 1,425-kg satellite aloft. IRNSS-1A is the first of seven satellites that will make up the new constellation: four satellites... read more

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