According to the Belgian GNSS receiver manufacturer, its engineers “are currently processing further data sets to finalize the implementation of full BeiDou support. Although the BeiDou constellation is still being deployed, the data analysis already shows promising results.”

Figure 1. Top: Computed height above reference point (m) for GPS-only, GPS+GLONASS and GPS+GLONASS+BeiDou vs. time of day (hour).

The bottom panel of Figure 1 shows that, even with the current BeiDou constellation (15 satellites total, of which five are geostationary over China, five in full mid-Earth orbit similar to GPS and GLONASS, and five in inclined geosynchronous orbit over Asia), the total number of satellites used over the European region reached 26 for a short moment.

Figure 2. L1 pseudorange residuals (m) for GPS (L1 C/A, top) and COMPASS (B1-I, bottom) vs. time of day (hour).

Figure 2 shows the L1 pseudorange residuals for all constellations individually. This comparison highlights the advantage of the GPS constellation, which builds on two decades of real-time orbit prediction. The BeiDou orbits are “quite accurate for a relatively young constellation, but show typical meter-level jumps when ephemerides are updated,” according to Septentrio.

Septentrio says that the new feature will soon become available on selected company platforms. Users of its multi-constellation receivers will then benefit from improvements in urban availability and signal integrity, thanks to the augmented signal coverage.

L-3 Interstate Electronics Corporation (IEC) conducted an operational demonstration of its new TruTrak Evolution (TTE) Type II Selective Availability Anti-Spoofing Module (SAASM) GPS receiver at AUVSI’s Unmanned Systems North America 2012 conference, held last week in Las Vegas. The demonstration highlighted the new TruTrak receiver’s multi-use capabilities as a high-performing Ground-Based GPS Receiver Applications Module (GB-GRAM) for use on UAS platforms and precision weapons.

The TTE offers native Inertial Measurement Unit (IMU) and external oscillator interfaces, user processor, reconfigurable input/output (I/O) and front end, and easy roadmap migration from SAASM to NextGen GPS YMCA modernized technology. Its TTE Type II architecture supports the integration of multiple sensors to simplify all-source navigation solutions for GPS-denied environments. The adaptable architecture allows developers to quickly integrate new sensors without a hardware change, while providing industry-leading core GPS receiver performance and easy migration to NextGen modernized GPS.

“The TTE Type II highlights L-3 IEC’s integrated SAASM/NextGen GPS M-Code roadmap, providing another innovative path in the development of a Common GPS Module,” said Ric Pozo, general manager and vice president of navigation systems at L-3 IEC. “It allows SAASM- based P(Y) and modernized YMCA multichip modules to share a common circuit card assembly, making this a very flexible solution for drop-in GPS receiver replacement and low-risk integration.”

L-3′s TTE Type II provides features required by multiple applications, including a small form factor, high performance, and both passive and active antennas. The TTE Type II adopts the common GB-GRAM Type II electrical and physical interfaces, but with expandable I/O to support a wide range of requirements for ground, air, weapon, and projectile needs.

The Coast Guard’s Navigation Center is assigned responsibility as the operational arm and executive secretariat for the committee and assists the States and Local Government Subcommittee to bring this information to state government and private personnel in regional areas of the United States. View an agenda and directions to the meeting on the Navigation Center’s website.

CGSIC meetings are free and open to all and present an opportunity to personally interact directly with the people that manage the GPS program. For more information, call CGSIC Executive Secretariat Rick Hamilton at 703-313-5930.

Luch-5B, the second of a set of three geostationary satellites being launched to reactivate Roscosmos’s Luch Multifunctional Space Relay System, has been delivered to the Baikonur Cosmodrome. It arrived together with the Yamal-300K satellite in a single shipping container aboard an Antanov An-124-100 Ruslan flight from Krasnoyarsk.

This marked the first time that Information Satellite Systems – Reshetnev has used the special container, which is large enough to carry two middle-class spacecraft at one time. According to the company, sophisticated equipment fitted with a control system that helps monitor the environment inside the container helps avoid any chances of external damage or unwanted environmental impact during transportation.

Luch-5B is now undergoing preparations for launch.

The Luch system will be used to relay communications and telemetry between low-Earth-orbiting spacecraft, such as the the Russian segment of International Space Station, and Russian ground facilities.

The system’s satellites 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 DoD’s Global Positioning Systems Directorate.

As previously reported, Luch-5A, which was launched on 11 December 2011, has been placed in an orbital slot at 95 degrees east longitude. It began transmitting corrections on July 12, 2012, using PRN code 140.

Luch-5B, scheduled for launch on September 7, 2012, will be positioned at 16 degrees west longitude.

Satellite Luch-5B in an anechoic chamber at ISS-Reshetnev.

UPDATE: Title changed to clarify that GPS signals are not affected, but the transfer of the GPS data to the broadcasters.

GPS is playing a role at the 2012 Olympics in London, through apps for smartphones to transportation issues, and even a clash with social media.

Twitter Disrupts GPS Data from Olympic Cyclists to Broadcasters

The International Olympic Committee (IOC) said that social media prevented broadcasters from getting accurate GPS data about the precise location of Olympic bicycle competitors during the155-mile men’s cycling road race.

According to Reuters, commentators on Saturday’s men’s cycling road race were unable to tell television viewers how far the leaders were ahead of the chasing pack because data could not get through from the GPS satellite navigation system traveling with the cyclists.

IOC spokesman Mark Adams says the Olympic Broadcasting Services service was jammed by “hundreds of thousands” of people sending texts, pictures and updates to social networks such as Twitter and Facebook, the Washington Post reports.

To alleviate the bandwidth issue, the IOC asked users not to tweet, saying unless it’s an “urgent, urgent one, please kind of take it easy.”

The problem arose due to lack of data bandwidth provided by telecom carriers, which did not properly anticipate demand. CNET’s Zack Whittaker reports that users send almost 10 million tweets during the opening ceremonies alone.

The problem appeared to be solved for Sunday’s women’s road race.

Apps Spark User Interaction, Excitement

A number of mobile apps will help spectators at the Games keep tabs on the action.

SoFit Mobile. A Toronto-based mobile development company, SoFit Mobile, has released a free social-gaming app that uses GPS technology to track users’ steps as they compete with friends. Users can donate money to charity or unlock medals and real-life discounts and coupons based on how far they travel. Early participants were eligible to win tickets to the games.

The app is designed to connect users with friends virtually, regardless of geographical and cultural differences, where they can train together and take part in athletic events like the New York Marathon.

“Using the Olympics as a way to inspire more people to get active, SoFit will engage users to take small steps to start living healthier while connecting millions to make the world a better place,” said Olympic figure skater Michelle Kwan in a press release.

The app was developed in partnership with the Walk A Mile campaign, which was inspired by the 2012 London Games. SoFit is available for Apple and Android devices.

Samsung Hope Relay. For every mile run while this app is activated, Samsung donates 1 pound to charities, including Kids Company and International Inspiration. The app uses GPS to track the users’ movements walking, running, or cycling, alone or as part of a team.

TorchTracker. This app used GPS tracking to pinpoint where the Olympic Torch was as it made its way to the games, and helped fans find places to see it go by.

American and Australian Team Buses Get Lost

Before the games began, buses taking Australian and American athletes from Heathrow Airport to Olympic Park experienced a failure of GPS end users, sending the athletes around the city for a long tour before arriving at the Olympic Village.

The bus driver hired by London Olympic organizers had not driven or been shown the route before, and could not operate the GPS navigation system fitted in the vehicle. Also, some of the venues, such as the village, had not been pre-loaded into the devices.

For the Aussies, it turned into a 3½-hour marathon, accidentally taking them past central London landmarks such as Buckingham Palace and the Houses of Parliament.

A separate London 2012 bus carrying American athletes got so badly lost it took four hours to make the 23-mile trip across the capital.

Olympic Lanes and GPS Vehicle Tracking

After there were problems for the athletes getting to events in 1996, every host country has had an Olympic Lane to speed the journey for Olympians. However, residents have grumbled about it and there has been some talk about defying the rule and using the lane for unofficial business.

Blogger Oliver Ortiz posits that the conflicts could have been avoided if organizers had made use of GPS vehicle tracking. “The Olympic Lane is open from 6 a.m. until midnight both ways, and for many this is a folly. There will be certain times of the day when the Olympic Lane will be essential and it almost appears lazy on behalf of the Olympics organisers not to consider the best times for the lane to be open. If only they had thought about using GPS Vehicle Tracking to not only design the opening times, but also to monitor the Olympic Lanes during the games and make changes to when they are open. GPS Vehicle Tracking would have made these two things possible.

“London knew they were having the Olympics way back in 2005, could the Olympic Committee not have thought about levels of traffic and travel times at various points in the day using GPS Vehicle Tracking to put forward a more practical schedule for the Olympic Lane to be open?”

The two In-Orbit Validation (IOV) satellites launched in October 2011 joined the two Galileo In-Orbit Validation Element (GIOVE) satellites launched in 2005 and 2008, forming a mini-constellation. For a few hours on certain days, signals from all four satellites could be received by state-of-the-art multi-frequency, multi-constellation GNSS receivers. The researchers used the GIOVE plus IOV satellite observations made by a Trimble Navigation NetR9 receiver operated at the University of New Brunswick in Fredericton, Canada, together with precise orbit and clock data derived from observations collected on the COoperative Network for GIOVE Observation (CONGO) to obtain receiver positions converging to an accuracy of a few centimeters.

An article describing the researchers’ procedure and results obtained will appear in the September issue of GPS World.

Likely none of us needs a reminder as the upcoming leap second has been all over the news outlets for the past few days. But just to provide the details again, read this article.

Presumably, all GPS receiver manufacturers have checked to make sure their receivers will handle the leap second properly. However, at least one late-model high-end receiver from a leading manufacturer is currently reporting incorrect advance leap second information in its data files.

The European Satellite Services Provider (ESSP), the EGNOS system operator and EGNOS safety-of-life service provider, announced in a service notice dated 22 May that there might be an interruption in service for a 72-hour period should the leap second not be managed correctly.

AGI, a company that develops commercial modeling and analysis software for the space, defense and intelligence communities, has warned: “The consequence of failing to accommodate this event is that orbit in-plane motion and corresponding Earth orientation will both become inaccurate by at least one second until the leap second is properly implemented. This will also affect estimating orbits using time sequences of observations spanning this leap second event. GEO satellites might be inaccurate to about 3 km and LEO satellites to about 8 km. How great the discrepancy will be depends on how long one waits to implement the leap second. The probable inaccuracies may be within the collision keep-out zones of many satellites, causing either false alarms or totally missed threat detections.”

And it has also been reported that some computer operating systemsmight hang due to improper handling of the leap second.

An article on the upcoming leap second for the popular press may be found here. And, in case you missed it, a recent Physics Today article on the leap second and its future can be found here.

News courtesy of CANSPACE Listserv.

UPDATE: The Interfax news agency has announced that the rescheduled launch date for SES-5 from the Baikonur Cosmodrome, originally scheduled for June 18, is August 6, 2012.

The launch is being delayed due to a problem with a first stage subsystem on the Proton launch vehicle. The rocket has been rolled back to the assembly building for further tests.

SES-5 is also known as Sirius 5 stemming from the development of the Sirius satellite constellation by Nordic Satellite AB, now owned by Luxembourg’s SES.

The satellite carries a transponder for the European Geostationary Navigation Overlay Service (EGNOS). The transponder is intended to eventually replace or one of those on the currently used EGNOS satellites (Inmarsat 3-F2 at 15.5 degrees west using PRN 120, Artemis at 21.5 degrees east using PRN124, and Inmarsat-4-F2 at 25 degrees east using PRN 126 and designated for industry tests).

Unlike the present L1-only EGNOS satellites, SES-5 will have transponders on both the L1 and E5 frequencies similar to the setup on the Wide Area Augmentation System satellites, which broadcast on L1 and L5.

SES-5 is to be stationed at 5 degrees east longtiude.

A second SES satellite with EGNOS transponders is under construction. The SES Astra 5B satellite is scheduled for launch in the second quarter of 2013 and will be positioned at SES Astra’s 31.5 degrees east orbital position.

Role Switch. On March 22 and 23, Inmarsat-4-F2 at 25 degrees east using PRN126 and Artemis at 21.5 degrees east using PRN124 switched roles. PRN126 became an EGNOS operational signal-in-space satellite while PRN124 became the test satellite, transmitting message type 0. PRN120 and PRN126 returned to service around 17:00 UTC on Tuesday, June 26.

According to an EGNOS service announcement dated April 3, the switch was due to the aging state of the Artemis satellite.