SiRF to Eliminate GPS Satellite Acquisition Lag - SiRF InstantFixII
SiRF announced some news this morning that will make using a GPS a lot better, and it involves limiting that acquisition time to get a satellite fix, known as Time to First Fix, to as little as five seconds. The new capabilities, SiRFInstantFixII, will be included on SIRF Star III chipsets and allows the chipset to model where the satellites will be in the sky for up to three days into the future.
A little basic info here: The GPS' job is a pretty tough one, with satellites sending out time stamped signals once every 30 seconds, the GPS has to lock onto a signal from at least three, preferably four or more satellites figuring out what the time lag is on that signal, and as a result calculating the distance from the GPS to that satellite. Without something like Instant Fix, the GPS has to search the entire sky noticing signals and checking time lags. With Instant Fix, it will know that the certain satellite will be in a specific position so it will only look there instead of everywhere.... speeds the process way up. TomTom and others have this type of service, but it requires you plugging the GPS into a computer and downloading those satellite location predictions every week or so.
The press release below has a quite from Mio's President, so I would look for Mio units at CES to include the new chipsets.
Press release follows...
SiRF Technology today introduced SiRFInstantFixII, an autonomous version of SiRF's original SiRFInstantFix technology that is designed to significantly improve the start-up times of portable navigation devices (PNDs) and other mobile navigation devices without needing any network connectivity for assistance or updates. Available now for both SiRFstarIII GPS receivers and SiRFatlas and SiRFtitan multifunction SoC navigation processors, SiRFInstantFixII achieves GPS start-ups in as little as five seconds so that mainstream consumers can begin navigating as soon as they're ready to drive.
"Our groundbreaking SiRFInstantFixII technology makes the frequent start-up waits for PNDs a thing of the past," said Kanwar Chadha, founder and vice president of marketing for SiRF Technology. "By not requiring any network connectivity or downloads, it significantly improves the daily navigation experience for consumers of mobile navigation devices."
SiRFInstantFixII can reduce warm starts, the typical PND start-up mode, from over half a minute to as little as five seconds, and in urban canyons the difference can be even more significant. SiRFInstantFixII does this while demonstrating excellent positional accuracy, an important attribute for navigation devices. SiRFInstantFixII accomplishes this using sophisticated, patent-pending algorithms that enable the PND to model the behavior of visible GPS satellites during the day and predict their position in the sky for up to three days in the future. SiRFInstantFixII continuously refines its calculations based on the latest data it receives from the satellites being tracked every time the PND is used. SiRFInstantFixII performs these calculations completely autonomously, without ever needing updates of any kind from a network.
"We are very excited about the positive effect that SiRFInstantFixII will have on the PND user experience. Through our close alliance with SiRF, we look forward to bringing more innovative technologies to market and helping consumers to enrich their life and the way they see the world," said Samuel Wang, President of Mio Technology. "Helping consumers to explore more is the Mio Technology company mission. As a leader in the mobile navigation device market, we strive to provide consumers with a positive, free-spirited, open, unexpected and seamless user experience, and we believe that eliminating the start-up wait commonly experienced by many PND users is a great step in that direction."
The new SiRFInstantFixII has been specifically designed to meet the needs of mass-market consumers using non-connected devices where a network-based update would be cumbersome or otherwise undesirable. Manufacturers already using SiRF's original SiRFInstantFix will find it continues to provide consistently high performance for network-connected devices and for products where updates can be performed seamlessly with little or no user interaction. SiRF offers manufacturers the greatest flexibility to choose between the new "unplugged" SiRFInstantFixII (with three days of satellite predictions) for PND type devices, which may have no connectivity, and the "classic" SiRFInstantFix (with up to seven days of satellite predictions) for connected devices to best meet their end customer requirements.
While in theory determining location using GPS satellites is a simple process of triangulation, the reality is much more complex. First, the GPS receiver needs to find and "lock" onto enough satellites to be able to calculate its location, a process called acquisition. With its 200,000 correlators, SiRF's innovative SiRFstarIII architecture made the acquisition of satellites very fast. To calculate accurate position, however, the GPS receiver needs to know where each of these GPS satellites is in the sky with a very high degree of accuracy.
Every satellite requires 30 seconds to broadcast its precise location, and the GPS receiver must be able to download this data from each satellite it needs for a fix. This data is typically valid only for two to three hours. If anything interrupts the signal while receiving this data, such as a building or tree, the receiver has to wait another 30 seconds to completely download the data from the satellite. In real-world conditions, where the GPS receiver is usually moving, it can take up to several minutes to obtain all the data the receiver needs to perform its calculations and obtain a fix, resulting in a long period with a great deal of location uncertainty before navigation can begin.
Using SiRFInstantFixII, affordable PNDs can not only start tracking satellites and navigating more quickly, they can do it using signals much weaker than those needed to obtain satellite position data the traditional way, removing the barrier that often stands in the way of successfully navigating under tough GPS signal conditions.
Read More in: CES 2008
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Posted by Scott Martin at January 2, 2008 9:13 PM