GIOVE-B Bom Bursts

GNSS: Update

The ESA is fed up with the delays surrounding the Galileo program in general and GIOVE-B in particular and has commissioned Surrey Technologies to build GIOVE-A2. Without an active satellite, Galileo stands the risk of losing its frequency licenses. Moreover, it is still unclear whether the last Beidou launch was successful or not. Glonass, however, is investigating the use of GPS / Galileo-like transmission techniques.

By Huibert-Jan Lekkerkerk

Artist’s impression of GIOVE-A2 (source: www.esa.int).

Aircraft Landing Using GPS

In December 2006 the first successful landing using GPS was performed in Australia. The GPS receiver was augmented with a ground-based augmentation system. At the moment GPS may only be used, in combination with WAAS, for the approach phase and not in the final landing. Qantas, the national Australian airline, has so far equipped nine Boeing 737s with a prototype system. The system will be further developed based on the test results. It is expected that the system will be fully operational and certified within two years.

Original Galileo architecture (source: www.esa.net)

SiRF (America), one of the main GPS chipset suppliers, has developed a hybrid GPS – WiFi chip with Skyhook (America). Using the algorithms developed by Skyhook, the chipsets can be used for both indoor and outdoor positioning. The basis of the technique is a database containing over 50% of the known WiFi hotspots in America. Using triangulation, the distances between the chip and the transmitter, and hence the position, can be calculated. Together with cellular positioning, this is a promising development in solving one of the greatest problems in satellite navigation – indoor positioning.

Galileo

GIOVE-A Signal

In March the ESA released the so-called Interface Control Document listing the signal details of GIOVE-A. Earlier there was controversy around this signal since in differed from the specifications detailed in the general Galileo Interface Control Document. With the release of the GIOVE-A document, it is now possible for suppliers to develop their own test receivers.

GIOVE-B

During a speech on January 17 Jean-Jacques Dordain, general manager of the ESA, issued a warning to Galileo industries. The latter, consisting of four major European companies, is responsible for the building of the GIOVE-B satellite as well as the first four production satellites. In order to keep the radio frequencies for Galileo, at least one Galileo satellite needs to be operational and transmitting on these frequencies.

GIOVE-B, whose launch was planned for spring 2006, has still not been launched. It is rumored that it shorted out during a test last summer and has still not been completely repaired. The main issues seem, however, to lie within the organization of the consortium. There is much distrust between the consortium partners. Dordain has stated that the satellite should be finished before the end of March 2007. If not, measures would be taken. At the time you read this, it should be clear whether measures have been taken or not. In the meantime a contract was awarded to Surrey Technologies to build the GIOVE-A2 satellite, a satellite that was not planned for originally. Surrey, a small English firm, was responsible for building GIOVE-A which has been functioning without problems since its launch in December 2005. GIOVE-A2 should safeguard the Galileo frequencies should it be impossible to launch GIOVE-B on time.

Launch of Chinese long march rocket used to launch the Beidou satellites.

In March, the European Commissioner for Transportation, Jacques Barrot, issued an ultimatum to the eight companies that will exploit Galileo once it is built. He stated that the quarrelling companies should create a single exploitation company before May 11, 2007. If they do not, they are not guaranteed to keep the exploitation contract. If these problems continue, there is not just the risk of gross budget and planning overruns, but also the possibility that Galileo will never be built. Some of the proposed exploitation companies already have their doubts about the profitability of Galileo.

Galileo Services

The Galileo Services organization, a non-profit organization developing new applications for Galileo, has been expanded to include non-European companies. Amongst the first new members from outside Europe are Novatel and Javad.

Glonass

GPS – Glonass Conference

A joint conference between America and Russia on interoperability between Glonass and GPS was held in December 2006. One of the items under discussion was the technique used within Glonass for coding the satellites. GPS (and Galileo) use a limited number of frequencies for all satellites and a unique code for each satellite. Glonass however uses a unique frequency for each satellite. If, and to what extent, changes will be made to the Glonass structure is not yet known. If Glonass decides to use the GPS/Galileo technique, this will have such a huge impact on the price of combined receivers that they may become available to the consumer market.

Satellite Status

The Glonass constellation is relatively constant. There are now 19 Glonass satellites. Of these 19 only 9 are active, however. Three satellites are currently being maneuvered into position and will probably become active after that. The other seven satellites are not expected to become active again.

Beidou

On February 2 the fourth Beidou satellite was launched. It seems that the satellite has not left the parking orbit to go into the designed geo-synchronous orbit. It is possible that the launch was unsuccessful, but it is also possible that the satellite is ‘parked’ in order to directly replace a failing satellite when necessary. There is no Chinese comment to either confirm or deny this.

Loran

Although Loran (Long Range Navigation system) is not a satellite navigation system, it is considered by more and more specialists to be a necessary backup to systems such as GPS, Glonass and Galileo. At the moment a lot of (American) effort is going into the modernization of the current Loran-C system. The modernized version, eLoran, is expected to become operational over the next few years. In Europe the awareness that additional navigation systems are necessary alongside satellite navigation systems is growing. Loran seems a logical choice since there are already some Loran chains active.

Huibert-Jan Lekkerkerk (hlekkerkerk@geoinformatics.com) is a freelance writer and trainer in the fields of positioning and hydrography.