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Geoinformatics-8-2008
article terminiation of p(y) determining that it is code in 2020 functioning as expectin the last gnss ed. according to sst review the possible the new maser clocks termination of the on board giove-b p(y) code on both l1 promise improved and l2 was menaccuracy compared to tioned. on september the rubidium clock on 23, the us departgiove-a. ment of defense (dod) procurement plan published a notice the european comstating that it will mission (ec) has narindeed cease to suprowed the list of port codeless / semipotential contractors codeless gps access down to 11. with the as of december 31, procurement process 2020. this means that open to non-european after this date there is companies, a consorno guarantee that the tium lead by current l1 / l2 type lockheed martin is receivers, as used for artist impression of the galileo system now in the running for example in rtk surbuilding the ground veying, will work. the control system. dod has stated that it "will reassess the transition date should signifithe procurement as a whole is not progressing very quickly according cant gps program delays arise." to astrium satellites and thales alenia space which have urged the ec interoperability to accelerate the process. at the moment it is expected that no congps - galileo tracts will be signed until at least mid-2009. how this will affect the the united states and europe have renewed their vows for the interopplanning of galileo is unclear. erability of gps and galileo. representatives from both have met at glonass the us naval observatory in washington (usa). one result of the joint in september 2008 a total of three glonass satellites had been sucwork has been the so-called common civil signal referred to as l1c cessfully launched, bringing the number of satellites to 17 at the time (gps) and e1 open service (galileo). this signal is already being transof writing. another 3 satellites are planned for launch on december 25, mitted by giove-b as well as a gps-galileo time offset signal. 2008. the intention is still to have 30 glonass satellites in orbit by compass versus the world 2011. the interoperability between chinese built compass and galileo / gps the good news is that the russian space program has received addiis running less smoothly. so far galileo / gps have assumed that tional funding of $2.6 billion from the russian government, most of compass would do something about the signals planned on galileo / which will go into new satellites. in addition, putin has plans to sign gps frequencies. although no definitive answer has been given to that for another $1.8 billion. assumption, a recent study from taiwan suggests that interoperability meanwhile production of the first glonass-k satellites is well under way, is not high on the compass priority list. with the first scheduled for launch in 2010. this type of satellite should compass will consist of 35 satellites in total and should begin operalast at least 12 years compared to the few years the current glonass-m tion in 2013. of the 35 satellites, 27 will be orbiting similarly to the satellites last. other gnss. three satellites will be in so called inclined geo-syngagan chronous orbits while the last 5 will be geo-stationary. with this mix the indian government has approved a $169 million funding for the the satellite visibility of compass will be improved relative to other indian gps-aided geo augmented navigation (gagan) project. according gnss. to indian aviation minister praful patel the gagan system would cerone of the conclusions of the study is that compass alone can protainly be in place by 2011 . vide similar performance to the galileo / gps combined system . as a gagan is the indian equivalent to the us waas; european egnos and result there is a good possibility that there is, from the point of view japanese msas. of system design, no need for integration of gnss over asia. galileo surrey satellite technology (sst) has received an award from the european space agency (esa) for its contribution to the galileo program in general and giove-a in particular. giove-a, which was supposed to operate until spring 2008, has already had its mission extended. furthermore the satellite appears to be more robust than giove-b since it remained unaffected by a surge of radiation that forced giove-b into safe mode for a week in september. the in-orbit testing for giove-b has meanwhile been completed by sst, latest news? visit www.geoinformatics.com huibert-jan lekkerkerk hlekkerkerk@geoinformatics.com is project manager at idsw and freelance writer and trainer. this article reflects his personal opinion. 31 december 2008
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