The National Geodetic Survey (NGS) has issued a “Kinematic GPS Challenge” to the community in support of NGS’ airborne gravity data collection program, called Gravity for the Redefinition of the American Vertical Datum (GRAV-D). The “Challenge” is meant to provide a unique benchmarking...More>>

Nearly half of all highway fatalities occur from unintended lane departures, which comprise approximately 20,000 deaths annually in the United States. Studies have shown great promise in reducing unintended lane departures by alerting the driver when they are drifting out of the lane. At the core...More>>

GPS precise point positioning (PPP) ambiguity resolution (AR) is a challenging task for ambiguity-resolved PPP. So far, two PPP AR methods, i.e. un-differenced decoupled clock model and single-differenced between satellites model, have been proposed. Various publications have demonstrated that the...More>>

The National Geodetic Survey (NGS) is conducting a 12-year project to re-define the vertical datum of the US. This project, referred to as GRAV-D (Gravity for the Redefinition of the American Vertical Datum), is accomplished by flying airborne gravity missions over the continental and coastal US. ...More>>

The present GLONASS navigation system uses frequency division multiplexing (FDMA – Frequency Division Multiple Access) to make the signals from individual satellites distinguishable. This results in the use of several adjacent frequencies for the broadcast signals in the two frequency bands L1...More>>

The Garada project, funded by the Australian Space Research Program, aims to establish an Australian space engineering capability to provide a disaster-monitoring earth observation system. Satellite-borne earth observation is very important for Australia and for other countries that need to monitor...More>>

This blog presents an efficient procedure for directly geo-referencing static 3D laser scans. This is a worthwhile way to obtain the required transformation parameters from the local sensor-defined coordinate system to a global system. Therefore, a multi-sensor systems (MSS) is designed with a...More>>

There are some navigation applications for which the performance of current MEMS inertial units is not sufficient to achieve the desired navigation accuracy. For such applications, one of the foreseeable solutions is to use redundant number of inertial sensors together to generate more accurate...More>>

As announced in IGSMAIL-6354, the IGS will adopt a new reference frame called IGS08 that should be used together with igs08.atx, an updated set of receiver and satellite antenna phase center corrections. Those will replace the absolute phase center correction model igs05.atx adopted in November...More>>

As announced in the previous post, the IGS will switch from the (IGS05 + igs05.atx) framework to (IGS08 + igs08.atx) in the coming weeks. Many users have accumulated results expressed in the old framework, either based on the regular IGS operational products since November 2006, or in concert with...More>>