Good News and Plenty of It

Headshot: Alan Cameron

Firing on all cylinders — to use a slightly outmoded technological metaphor — GNSS moved forward on virtually every front in the past month. GPS made major advances both on the ground and in space, Galileo took a giant step, Compass continued on its roll, GLONASS has good news pending in only a day or two (knock on wood), and GAGAN is settling into space. But the best news of all is a very quiet, indeed somewhat hidden item: the UK patent applications against the interoperative GPS/Galileo signal design appear to have been dropped.

Let’s eat dessert first, since life is uncertain.

Patent Dispute Evaporates

Vague rumblings emerged throughout spring and summer this year that two British technologists, backed by the U.K. Ministry Defense, had filed patents on the future interoperable GPS and Galileo binary-offset carrier signal designs. If granted and enforced, the patents would have severely disrupted modernization plans for both systems and levied unexpected costs upon receiver manufacturers. And in fact a company called Ploughshare Innovations Ltd. Started dialing up said manufacturers and asking for payment of royalties, based on the patent filings.

After significant uproar and negotiations before and behind the scenes, it now appears that the initiative has been quietly scuttled. The file on application number 11/774,412, Modulation Signals for a Satellite Navigation System, on the U.S. Patent Office’s website, now reads “Expressly Abandoned — During Examination.” The status is dated September 16, 2012, some time ago, but that I’m aware of, no parties involved, whether as filers or negotiators, ever made any kind of announcement about it.

Checking the European Patent Office and its registry — which by the way is no trivial task of website navigation — I found a note under the docket for EP1830199, Modulations Signals for a Satellite Navigation System stating “Patent surrendered.” Dated September 24, 2012. A few days later, another note: “Lapsed in a contracting state announced via postgrant inform. From Nat. Office to EPO,” with further information to the effect of “lapse because of failure to submit a translation or the description or to pay the fee within the prescribed time limit.” And for good measure, a final docket not on October 3, “Lapsed due to resignation by the proprietor.”

However abstruse and arcane, we’ll take good news however we find it. Another bullet dodged.

GPS Ground Segment Benchmark

The GPS Directorate announced on October 26 that the U.S. Air Force and Raytheon have successfully met all requirements to enter into the engineering and manufacturing development phase of the Next-Generation Operational Control System (OCX). OCX will replace the current GPS operational control segment in managing the satellite constellation and providing command and control for all modernized signals.

OCX is being developed and fielded in blocks of GPS capability, to align with GPS III and military equipment deliveries.

OCX Block 0, also known as the Launch and Checkout System, scheduled to be available in the fourth quarter of Fiscal Year 2014, will allow OCX to support the launch of GPS III satellites.

OCX Block 1, scheduled to transition to operations in the first quarter of 2016, will deliver the operational capability to command and control the entire GPS constellation including GPS II and GPS III satellites. This block will also control the legacy civil and military signals, as well as two modernized civil and military signals, L2C and L5.

OCX Block 2 will specifically support advanced capabilities for civilian and military signals, the international civil signal, L1C, and the military signal, M-Code. OCX Block 2 is currently synchronized with modernized signal broadcast and timing.

GPS Block IIF-3 satellite.

GPS Block IIF Satellite Rises, Reaches Station, and Transmits

On October 11, The L5 transmitter aboard GPS Block IIF-3 satellite SVN65/PRN24 was switched on, transmitting the civilian safety-of-life GPS signal, designed to meet demanding requirements for safety-of-life transportation and other high-performance applications.

A day earlier, SVN65 began transmitting L1 and L2 signals as PRN24 on October 8. A number of stations of the International GNSS Service are tracking the satellite. As of press date for this magazine (October 25) the satellite is included in broadcast almanacs although it is set unhealthy and will continue to be so until satellite commissioning is completed. The satellite is drifting towards its designated orbital position of Slot 1 in Plane A.

The launch of the GPS Block IIF-3 satellite took place as scheduled October 4, aboard a United Launch Alliance Delta IV rocket from Cape Canaveral, Florida.

Galileo Turns Four. Validation Satellites, That Is.

The Galileo control room.

On October 12, a Soyuz launcher carrying two Galileo In-Orbit Validation (IOV) satellites deployed its twins into orbit within four hours after take-off, at close to 23,200 kilometers altitude. They join two earlier IOV spacecraft launched in October 2011. Once all four are operational in space, they will provide the minimum number of satellites required for navigational fixes — enabling system validation testing when all are visible in the sky.

A week after the dual liftoff from Kourou, French Guiana, the two satellites completed the critical Launch and Early Orbit Phase on October 19-20.

Satellites FM3 and FM4 satellites were handed over from the joint ESA/CNES Launch and Early Orbit Phase (LEOP) team in Toulouse, France, to the Galileo Control Centre, Oberpfaffenhofen, Germany, from where Spaceopal will manage operations of the Galileo constellation.

Three orbit maneuvers were conducted for each satellite to start them on drift orbits towards their operational positions, where they are expected to arrive on November 10 (FM3) and November 12 (FM4) after a series of drift-stop and fine-positioning movements.

The satellites were configured into a secure mode shortly after handover. While underway to their final positions, they will also undergo a series of tests to confirm the performance of their subsystems before switching on the payload.

The satellites were built by a consortium led by the Astrium division of EADS, which produced the platforms and has responsibility for the payloads, while Thales Alenia Space handled assembly and testing.

Compass up to Eleven

The two BeiDou-2/Compass satellites launched on September 18 reached their circular medium-Earth orbits on October 1 and started transmitting navigation signals. Several stations participating in the International GNSS Service’s Multi-GNSS Experiment as well as some in the Cooperative Network for GNSS Observation started tracking the satellites on September 26.

Although semi-official rumors had circulated that  China was preparing for the Compass G6 (G2R) satellite launch on October 25, we have not found any announcement that the event has occurred.

The November issue of GPS World will appear in a few weeks’ time, with a cover story on “What Is Achievable with the Current Compass Constellation?” The technical article by Chinese researchers gives data from a 12-station tracking network distributed through China, the Pacific region, Europe, and Africa. It demonstrates the capacity of Compass with a constellation comprising four geostationary Earth-orbit (GEO) satellites and five inclined geosynchronous orbit (IGSO) satellites in operation. The regional system will be completed around the end of 2012 with a constellation of five GEOs, five IGSOs, and four medium-Earth orbit (MEO) satellites. By 2020 it will be extended into a global system.

GLONASS News in a Day or Two

As we go to e-press with this e-newsletter on October 30, we look forward to a Russian rocket rising on November 2 with a Luch data-relay satellite payload to service the the Russian satnav system. The second of a set of three geostationary satellites launched to reactivate Roscosmos’s Luch Multifunctional Space Relay System, it will also carry transponders for the System for Differential Correction and Monitoring (SDCM), Russia’s satellite-based augmentation system. The transponders will broadcast GNSS corrections on the standard GPS L1 frequency using C/A PRN codes assigned by the GPS Directorate. According to the most recent announcement, it will be positioned at 16 degrees West longitude, joining Luch-5A, already  in an orbital slot at 95 degrees East longitude.

GAGAN Unfolding

The Indian Space Research Organization announced on October 3 that orbit-raising maneuvers placed  the GSAT-10 satellite, launched September 30, in an orbit with 35,000-kilometer high orbit, with an orbit period of 23 hours 50 minutes, and a designated location of 83 degree East. GSAT-10 contains a payload to support the Indian GPS and GEO Augmented Navigation (GAGAN) satellite-based augmentation system. The satellite will likely use PRN code 128.

Another Dispute Headed for Resolution?

Finally, another pink dawn on the horizon. The European Union (EU) and China will reportedly meet in December in Paris to discuss overlapping radio frequencies both plan to use for their future encrypted government/military satellite navigation services.

The meeting will be conducted under what the Joint Statement on Space Technology Cooperation specifies as the ITU Framework. ITU is the International Telecommunication Union of Geneva, a United Nations affiliate that regulates satellite orbital slots and frequencies.

The statement was signed as an annex to a broader EU-China summit held September 20 in Brussels. The two sides continue collaboration on satellite navigation despite the signal conflict, which has been a subject of debate for at least two years.

The 27-nation EU and China have agreed to continue the China-Europe GNSS Technology Training and Cooperation Center.