B: Applications Archives - Page 144 of 151 - Inside GNSS - Global Navigation Satellite Systems Engineering, Policy, and Design

B: Applications

April 8, 2008

GNSS on the Go–Sensitivity and Performance in Receiver Design

Position tracking is no longer limited to fixed automotive applications or expensive handheld tracking systems.

Consumer demand combined with recent innovations in GNSS technology is making position tracking a must-have feature in a wide range of cost-sensitive applications, including cellular handsets, personal navigation systems, and other consumer electronic devices.

Position tracking is no longer limited to fixed automotive applications or expensive handheld tracking systems.

Consumer demand combined with recent innovations in GNSS technology is making position tracking a must-have feature in a wide range of cost-sensitive applications, including cellular handsets, personal navigation systems, and other consumer electronic devices.

Developing a GNSS position tracking subsystem for consumer electronic devices can appear to be a daunting challenge. Developers must not only keep down costs while maximizing performance and accuracy, they have to do so using RF technology with which they may have little experience.

Sensitivity is the key to accuracy of a GNSS receiver. The signals that a GNSS receiver tries to detect and process are buried in noise; therefore, the task of maintaining signal integrity is a key challenge for many developers.

This article describes how becoming familiar with a few key aspects of RF design can help developers avoid many of the seemingly arbitrary design decisions that can cause position tracking functionality to fail to achieve sufficient accuracy. It also highlights how developers can exploit software-based GNSS baseband architectures to reduce RF subsystem complexity while further increasing sensitivity and positioning accuracy. . .

Conclusion
. . . By understanding that RF sensitivity is the key to accuracy, developers can avoid common design pitfalls that delay time to market and increase system cost.

Additionally, by using the proper components and taking advantage of next-generation innovations such as software-based baseband processing, developers can achieve the best sensitivity and accuracy without having to become RF experts themselves.

(For the complete article, including figures, charts, and images, please download the PDF version at the link above.)
By
April 7, 2008

The Art of ARTUS–A Second-Generation Galileo/GPS Receiver

Creation of new global navigation satellite systems and modernization of existing ones is introducing many new signals across a wide swath of RF spectrum now and in the near future. These developments are accompanied by a growing need to design new GNSS receivers that can work with new signal structures on an increasing number of frequencies.

Europe’s Galileo program has supported a number of activities intended to promote innovations in receiver design, such as prototype Galileo user equipment, reference receivers, and so on.

Creation of new global navigation satellite systems and modernization of existing ones is introducing many new signals across a wide swath of RF spectrum now and in the near future. These developments are accompanied by a growing need to design new GNSS receivers that can work with new signal structures on an increasing number of frequencies.

Europe’s Galileo program has supported a number of activities intended to promote innovations in receiver design, such as prototype Galileo user equipment, reference receivers, and so on.

One such activity is a project named ARTUS (Advanced Receiver Terminal for User Services), 50 percent of which is financed by funds allocated by the Galileo Joint Undertaking (GJU). A consortium of four companies is leading the ARTUS project (see "Acknowledgments" below)

ARTUS supports the development of receiver technologies to aid the research and development activities for Galileo “professional” receivers. These efforts are designed to facilitate the availability of Galileo professional receiver prototypes and antennas at an early stage.

ARTUS provides Galileo/GPS navigation capability. All three Galileo frequencies (L1, E6 and E5a/E5b) are supported as well as the GPS L1, L2 and L5 (L5=E5a) frequencies.

The receiver supports any BPSK (GPS-C/A, Galileo E5a and E5b (sideband tracking), AltBOC (E5ab), Galileo L1-B/C (BOC(1,1)) as well as BOCc(15,2.5) (E1-A / E6-A); GIOVE-A transmits BPSK (E5a/E5b/E6) and BOC(1,1) (E1).

Although the receiver can track the modulations foreseen for the PRS, it cannot generate the corresponding codes. One can, however, do performance measurements using periodic substitute codes.

Although not initially planned, the consortium has decided to also implement the GPS L2 band for commercial reasons. The unit performs the measurements and processes the raw data to provide an RTK solution.

The Artus design will also form the basis for a breadboard development of the next generation RIMS receivers. This development will be conducted in the frame of an ESA contract lead by IFEN with NemeriX and Euro Telematik as subcontractors.

This article describes the design and operation of the second-generation ARTUS receiver with a particular focus on innovations in four key areas: antenna, RF front-end, digital baseband processing, and navigation software.

Although originally intended to focus primary on tracking Galileo and GPS signals, the flexible design of ARTUS also allows it to receive and track signals from the Russian GLONASS system and China’s Beidou.

After discussing the receiver design and operation, we will briefly describe some of the results of testing using combinations of laboratory GNSS signal simulators, signals-in-space, and simulated signals generated in the German Galileo Test Bed (GATE). . .

Conclusion
The ARTUS GNSS receiver described in this article offers a rich flexibility for various configurations of signals on different RF bands. The high performance antenna in conjunction with a flexible RF front-end design offers excellent performance on all currently available GNSS signal bands, including the upcoming Galileo system.

With the availability of up to 120 channels, the receiver is well equipped for future navigation systems; however, it can also be configured in a version with only 20 or 40 channels for tracking the currently available GPS (L1 and L2) alone.

The modular concept, applied even for the firmware of the baseband processor FPGAs, allows easy adaptation of the algorithms developed for the ARTUS receiver or fast implementation of new algorithms. And if the IP protocol is used, any user interface can easily connect — even remotely — to the receiver — whether for navigation or monitoring purposes.

The ARTUS project is now in its qualification phase. Further developments aim for the commercialization of the receiver.

(For the complete article, including figures, charts, and images, please download the PDF version at the link above.)


Acknowledgments

ARTUS was developed in the framework of a GJU 50 percent–funded project, contract GJU/05/2414/CTR/ARTUS. These activities have been taken over by the European GNSS Supervisory Authority (GSA). This support is gratefully acknowledged. IFEN served as the principal contractor for ARTUS.

The consortium members involved in the ARTUS receiver development are ifEN (overall system design and baseband processing), NemeriX (analog RF-front-end), Roke Manor Research (antenna and RF splitter), Leica Geosystems and inPosition (RTK software). In essence the ARTUS design is based on previous receiver developments carried out by IFEN in the frame of the German Galileo Test Bed (GATE).

GATE is being developed on behalf of the DLR (German Aerospace Center, Bonn-Oberkassel) under contract number FKZ 50 NA 0604 with funding by the BMWi (German Federal Ministry of Economics and Technology). DLR kindly gave its permission to publish the preliminary test results.

By

GNSS Hotspots | April 2008

One of 12 magnetograms recorded at Greenwich Observatory during the Great Geomagnetic Storm of 1859
1996 soccer game in the Midwest, (Rick Dikeman image)
Nouméa ground station after the flood
A pencil and a coffee cup show the size of NASA’s teeny tiny PhoneSat
Bonus Hotspot: Naro Tartaruga AUV
Pacific lamprey spawning (photo by Jeremy Monroe, Fresh Waters Illustrated)
“Return of the Bucentaurn to the Molo on Ascension Day”, by (Giovanni Antonio Canal) Canaletto
The U.S. Naval Observatory Alternate Master Clock at 2nd Space Operations Squadron, Schriever AFB in Colorado. This photo was taken in January, 2006 during the addition of a leap second. The USNO master clocks control GPS timing. They are accurate to within one second every 20 million years (Satellites are so picky! Humans, on the other hand, just want to know if we’re too late for lunch) USAF photo by A1C Jason Ridder.
Detail of Compass/ BeiDou2 system diagram
Hotspot 6: Beluga A300 600ST

1. FOLLOW THAT PIZZA!
Huntsville, Alabama
√ Eleven Papa John’s pizza stores in Huntsville, Alabama equip their delivery drivers with handheld PNDs and use a mapping engine developed by startup company TrackMyPizza to give customers 15 second online updates on their pizza pie. You don’t even need to leave your laptop to look out the window.

Read More >

By Alan Cameron
[uam_ad id="183541"]

Network Adjustment SW

NovAtel’s Waypoint Products Group offers the GrafNav/GrafNet Version 8.10 software, a high-precision GNSS post-processing package that supports raw data from most available GNSS receivers. Using data from both a roving station and as many as eight base stations, centimeter-level positions can be computed, according to the company. For applications in which base station setup is difficult or not desired, precise point positioning (PPP) is offered, which uses downloadable GPS clock and orbital corrections to compute solutions accurate to between 5 and 40 centimeters.

Read More >

By Inside GNSS

EADS Astrium Buys Surrey Satellite

SSTL Engineering Team with GIOVE-A at ESA Test Facility

EADS Astrium has signed an agreement to acquire Guildford, United Kingdom–based Surrey Satellite Technology Limited (SSTL) from the University of Surrey.

SSTL designed and built the first Galileo In-Orbit Validation Element (GIOVE-A), the only European GNSS satellite currently on orbit. The company also is building a second GIOVE-A spacecraft under contract to the European Space Agency (ESA).

Read More >

By Glen Gibbons
April 4, 2008

DoT Rescues NDGPS Project

The Nationwide Differential Global Positioning System (NDGPS) program has been salvaged from the political limbo in which it has resided for more than a year.

Following completion of an assessment by the U.S. Department of Transportation (DoT), the agency has decided to continue full NDGPS operations. Currently, 86 stations are operating with support from three federal agencies: the U.S. Coast Guard (USCG, 39 sites), the Army Corps of Engineers (9 site), and the DoT (38 sites operated and maintained by the USCG under contract).

Read More >

By Glen Gibbons
April 3, 2008

2008 ESRI Survey & Engineering GIS Summit

GPS Wing Commander David W. Madden will keynote ESRI’s Survey & Engineering GIS Summit in San Diego during the plenary session on Saturday, August 2. Col. Madden is responsible for the multinational, multiservice development of all GPS space, satellite, and ground segments.

Read More >

By Inside GNSS
[uam_ad id="183541"]
April 2, 2008

First Civil Funds for GPS Program

FY09 GPS Budget Request; FAA Line Item

The GPS program has passed a milestone of sorts with the first allocation of funds from civil agencies to pay for a portion of the core GPS budget.

The Fiscal Year 2008 (FY08) budget for the U.S. Department of Transportation (DoT) sets aside $7.2 million as the first installment on the civil share of GPS modernization efforts, including the L1C signal that will be transmitted on the GPS Block III satellites and costs of monitoring the civil GPS signals in the modernized ground control segment (OCX). For the FY09 budget, the Bush administration has requested a $20.7 million allocation. The total five-year civil contribution (FY09-13) is expected to be more than $200 million.

Read More >

By Glen Gibbons

u-blox Launches GPS Timing Module

u-blox LEA-5T

Swiss GNSS chip manufacturer u-blox has introduced a new precise timing GPS module, the LEA-5T, precise timing at the CTIA Wireless 2008 conference taking place this week in Las Vegas.

Based on the company’s 50-channel, fifth-generation chipset technology, the LEA-5T is intended for such applications as telecom network synchronization, use in WiMAX base stations for home-based broadband networks, and data communication among geographically dispersed systems and devices such as NTP servers.

Read More >

By Glen Gibbons
March 11, 2008

Another Successful GPS Launch, Plan Produce Back-Up and Improved Capability

Successful launch of a GPS Block IIR satellite on March 15 continues a U. S. Air Force initiative to bolster the nation’s GNSS constellation against anticipated failures of aging on-orbit spacecraft while improving system accuracy and accelerating the availability of new military signals.

An analysis of the condition of subsystems on GPS satellites in orbit last year indicated that up to nine GPS space vehicles (SVs) could fail in the near future, according to Col. David Madden, commander of the GPS Wing at the Space & Missile Systems Center, Los Angeles Air Force Base, California. “That’s what drove us down this path of launching five in one year,” said in a recent news conference.

Read More >

By Glen Gibbons
March 10, 2008

Europe Readies Galileo Procurement

Having transformed the Galileo program into a fully public procurement, European agencies have announced a schedule that would lead to contracts for the €3.4-billion project by the end of 2008. And non-European companies may be involved in providing certain components and services to the effort.

The plans were revealed in presentations by high-ranking figures from the European Commission (EC) and European Space Agency (ESA) speaking at the Munich Satellite Navigation Summit in Germany, February 19–21.

In comments at the conference, Jacques Barrot, EC Vice President and commissioner for transport and energy, and Giuseppe Viriglio, ESA director of telecommunications and navigation, indicated that they hope to see invitations to tender (ITTs, essentially, requests for proposals) to be issued July 1.

Deadline for tenders would follow within a few months, followed by a review of bids and contract awards in December. Identification of prospective bidders and requests for information will precede the ITTs, activities that will probably begin within the next few weeks.

The EC and ESA still need to complete a “delegation agreement” that would outline the responsibilities and principles under which ESA would act as the prime contractor — the procurement agent and design authority that will oversee the engineering work and contracts under which the ground and space infrastructure would be built. It will receive an estimated €195 million for that role.

ESA will set up a new Galileo directorate, Viriglio said, to handle its responsibilities. The European Commission will act as the Galileo program manager, taking on additional staff to handle the work, according to Paul Verhoef, head of the Galileo Unit in the EC’s Directorate-General for Transportation and Energy. The ESA directorate would have about 30–40 staff members and the EC Galileo unit would gain about 35 persons to handle program management, according well-informed sources.

The procurement contract schedule will have to be met in order to have a chance to meet the goal of Galileo having a fully operational capability (FOC) by 2013.

The acquisition is divided into six “work packages”: system engineering support, completion of ground mission infrastructure, completion of ground control facilities, launchers, satellites (26 in batches of 10–12, 6–8, and 6–8), and operations.

No company or consortium of companies may bid for more than two of the six packages. The prime contractors must subcontract at least 40 percent of the work to companies not affiliated with them.

In the program’s clearest statement of interest in gaining from the GNSS-related experience of other countries, Viriglio underlined the possibility for European industries “to rely on non-European sources for certain components and services in case of demonstrated substantial advantages in terms of quality and costs, taking account of the strategic nature of the European GNSS programs and of the EU security and export control requirements.”

ESA Takes the IOV Reins. Meanwhile, ESA has already taken over as prime contractor for the in-orbit validation (IOV) phase of the program after a billion-euro contract with European Satellite Navigation Industries (ESNI) was terminated in December. IOV includes construction and launch of four full-fledged Galileo satellites in 2009–2010 to form a mini-constellation for additional validation testing before the other 26 spacecraft are launched in 2011–13.

All the other IOV contracts will be retained as will the associated technical baseline, said Viriglio. European officials still need to figure out how they will cover an estimated $350-million overrun in IOV caused by delays, unexpected security costs, a change in the Open Service signal design as a result of the 2004 EU-US agreement on interoperability of GPS and Galileo, and dependence on a single customer (ESNI).

European officials repeatedly emphasized that the €3.4 billion was the most that they would spend on implementing Galileo, and that competition for contracts would take place under European Union (EU) rules rather than ESA procurement policy, which allocates 90 percent of funds to businesses based on the contributions from the member states in which they are located.

The calculation of $3.4 billion is based on cost estimates by ESA, drawn primarily from industry proposals and earlier studies and concession negotiations under the Public Private Partnership (PPP) concept, which was discarded last year. The largest portion of the costs would be for the space segment — building and launching satellites — estimated at €1.6 billion; the ground segment, €400 million; operations, €275 million; and systems engineering support, €150 million.

Members of aerospace companies that will probably compete for the contracts were less optimistic in their estimates of whether $3.4 billion will be enough.

Galileo has one satellite in orbit, the so-called GIOVE-A, which launched in December 2005 and will reach the end of its design life in March, although its builder, Surrey Satellite Technology Ltd., predicts that it will continue operating at least through the end of 2008. A second, larger spacecraft, GIOVE-B, is now scheduled for launch on April 26 from the Baikonur space center in Kazakhstan.

More than €2.6 billion has been spent on Europe’s satellite navigation program to date, mostly by the EC and ESA. This includes €133 million for the definition phase, €1.5 billion for the IOV phase, €520 million for the European Geostationary Navigation Overlay Service (EGNOS), and €480 million for Galleo-related projects financed through the EU’s Framework R&D programs. EGNOS is a satellite-based augmentation system that will be integrated into the Galileo infrastructure and operations over the next few years.

Who Calls the Shots? A new regulation regarding financing, governing structure, and procurement procedures for Galileo will be taken up by the European Council in April. But now that the funding and acquisition process have been largely resolved, the outstanding issue facing the Galileo program is governance, that is, the matter of political direction and control of the system’s implementation.

Now that the funding and acquisition process have been addressed, the outstanding issue facing the Galileo program is governance, that is, the matter of political direction and control of the system’s implementation. That, in turn, will have a substantial effect on whether the program is able to stay on schedule and within budget.

Until the abandonment of the PPP, that issue had seemed fairly clear. The European GNSS Supervisory Authority (GSA), a Community agency with a executive board made up of directors from the EU member states, would sign and monitor a contract with a private consortium to build and operate Galileo under a 20-year concession.

Now, however, the GSA has lost that primary supervisory role and has come under pressure from both the EC and the European Parliament, which approved the €3.4-billion Galileo program budget last November.

The 2004 EC Council regulation that created the GSA also assigned it other responsibilities: market development of the Galileo operational phase, GNSS-related research, technical certification of the components and services of the Galileo system, management of Galileo security aspects, coordinating radio frequency activity, and managing the agreement with an EGNOS service provider.

The EC would clearly like to bring the GSA back under its direct control, either as a separate but subsidiary entity or by absorbing key technical staff members into the Galileo Unit headed by Verhoef. “What we need is the expertise of the GSA, either directly or through a transfer to an EC office,” Verhoef said at the Munich conference.

Two related approaches are now under consideration: retaining a GSA, separately or within the EC, and restructuring it as a GNSS Security Agency that would handle GNSS security issues and, perhaps, technical certification of the Galileo system being built under the supervision of ESA. ESA would take over most or all of the GSA’s technical responsibilities and the EC Galileo Unit, as program manager, would acquire most of the rest.

Parliament Joins the Fray. In late January, Parliament weighed in with a proposal before the Industry, Research, and Energy (ITRE) Committee that would abolish the GSA, turn responsibility for ensuring the Galileo system’s security requirements over to a new Committee on European GNSS Programs, and establish an Interinstitutional Monitoring Group (IMG) consisting of representatives of the parliament, the European Council’s Presidency, and the EC.

The proposed actions amending the EC’s draft regulation for deployment and commercial operation of Galileo were tentatively approved at a January 30 committee meeting. A final vote on the regulation as a whole by the committee and, later, by the full parliament had not taken place as Inside GNSS went to press.

Parliament clearly feels emboldened by the fully public procurement of Galileo for which the legislative body must approve a budget. In a plenary session at the Munich Summit, Etelka Barsi-Pataky, a member of the European Parliament, noted that “Galileo is a Community project, fully funded from the public budget — taxpayer money.

“We need very strong political control of the project,” she said, noting that in the 11 years since the EC submitted its first communication on satellite navigation, “We have produced a ton of paper, a lot of studies, a lot of discussion. What we need now is to build an operating system.”

Although a “substitute” rather than a full member of the ITRE Committee, Barsi-Pataky is the Galileo rapporteur, the person appointed by parliament to investigate an issue or a situation and report back to it.

By Inside GNSS
IGM_e-news_subscribe