Maximizes Position Availability and Accuracy in Challenging Environments

• Dead Reckoning Sensor data is closely coupled with GPS measurements in the navigation filter to improve accuracy and reliability of position fixes.
• GPS measurements calibrate the DR sensors to ensure optimum speed and heading accuracy. DR measurements validate and correct GPS fixes during signal blockage and multi-path.
• Navigation is therefore continuous and reliable without having to rely on map-matching databases or high cost gyros
• Navigation available within 3 seconds of start-up
• GPS function carries over the high quality performance of the SiRFstarII architecture

Optional Software Feature for either the SiRFstarIIe/LP or the SiRFstarIIt chipsets:

SiRFstarIIt GSP2t Processor

• Integrated Signal Processor acquires and tracks satellites
• Raw measurements and GPS data output via serial port to host processor running SiRFNav or SiRFDRive navigation software
• On-chip analog to Digital converter for interfacing to low cost heading rate senors
• Odometer counter and forward/reverse indicator input
• SiRFNav host software integrates easily into host processors and operating systems using minimal resource overhead

GRF2i/ or 2i/LP – RFIC used with SSIIt and SSIIe/LP

• On-chip VCO and reference oscillator
• Integrated LNA and single stage down-conversion

SiRFStarIIe/LP- GSP2e/LP Processor

• Enhanced GPS core and ARM7TDMI processor
• On-chip 1Mb SRAM and 16 or 32 bit data bus to external ROM
• Runs SiRFDRive software plus end-user applications
• 40 GPIOs including odometer counter andforward/reverse indication.

SiRFDRive is a closely coupled Dead Reckoning option for both the SiRFstarIIt and the SiRFstarIIe/LP chipset's software suites. This option allows the navigation system to accept inputs from low cost heading rate sensors and vehicle speed wheel ticks in order to compute dead-reckoning positions when GPS signals are blocked or degraded.

Unlike most dead reckoning systems that function independently from the GPS part of the system, the dead-reckoning information is incorporated into the main navigation software filter through patented close coupling algorithms.

The route shown is through an urban environment including both urban canyon with mutlipath and partial blockage conditions, and in-tunnel operation. Navigation coverage is continuous and accurate with a mix of dead reckoning and GPS navigation.

SiRFDRive is designed to provide seamless and reliable positioning for GPS based vehicle positioning systems that require continuous and accurate position fixes under all GPS signal conditions and outages. Typical applications are auto navigation systems, road-tolling systems, telematics, navigation/radio entertainment systems, asset tracking, emergency response, CRM and fleet management. In the SiRFstarIIt version, the on-chip wheel tick counter and analog to digital convertor for heading gyros make it particularly economical for advanced automotive applications that have a host processor. The SIRFDRive version of the SiRFNav navigation software can be ported into the host's processor, operating system and memory, thus minimizing the incremental Bill of Material.

The SiRFstarIIe/LP version's onboard ARM processor makes it possible to design an all in one system that incorporates both the GPS and SiRFDRive software and the end user application software. Powerful development tools make it easy for the end user to port their applications to the SiRFstarIIe/LP system.

Either the SiRFstarIIt or the SiRFstarIIe/LP provide the same industry leading Dead Reckoning/ GPS performance.