TAG: multipath

Street Smart: 3D City Mapping and Modeling for Positioning with Multi-GNSS

July 1, 2015By
Figure 1. Example of the GNSS signal propagation using ray-tracing and a 3D building map.

A particle-filter-based positioning method using a 3D map to rectify the errors created by multipath and non-line-of-sight signals on the positioning result delivered by a low-cost single-frequency GPS receiver takes a multi-GNSS approach, using the combined signals of GPS, GLONASS and QZSS. The method outperforms conventional positioning in availability and positioning accuracy. It will likely be fused with other sensors in a future pedestrian navigation application. read more

Powerful RTK with Six Separate Engines

June 19, 2015By
Screen anatomy — RTK v6.

By Matthew D. Sibole A little more than a year ago, I became a part of a team of surveyors from across the country to offer testing and input on new technology and programing coming out of JAVAD GNSS. It has been a great honor to work along with Dr. Javad Ashjaee, the other surveyors and Javad’s staff at JAVAD GNSS. Why Javad chose me,... read more

This article is tagged with , , , , and posted in Survey

Galileo E1, E5a Performance for Multi-Frequency, Multi-Constellation GBAS

April 1, 2015By
Pullen-Galileo-O

Analysis of new Galileo signals at an GBAS compares noise and multipath in their performance to GPS L1 and L5. Even after smoothing, Galileo signals perform somewhat better than GPS and are less sensitive to the smoothing time constant. read more

MWC 2015: InvenSense to Ship Positioning Software for Smartphones

March 2, 2015By

InvenSense Inc. is making available its InvenSense Positioning Library (IPL) software, designed to provide sensor-assisted positioning in places where GNSS alone cannot provide desired accuracy. Invensense is a provider of intelligent sensor system on chip for motion and sound in consumer electronic devices. InvenSense made the announcement at Mobile World Congress, taking place in Barcelona, Spain March 2-5. The IPL incorporates advancements in sensor-assisted... read more

Tallysman TW5340 Smart Antenna Designed for Urban Canyons

November 6, 2014By

Tallysman’s new TW5340 smart antenna is designed to pair Tallysman‘s Accutenna technology antenna with STMicroelectronics’ Teseo II receiver. The combination makes the smart antenna accurate for use in all environments, including urban canyons, according to the company. The TW5340 is a multi-constellation GNSS Smart Antenna that provides simultaneous GPS/GLONASS/SBAS reception. It is designed for use in professional-grade applications such as precision timing, network synchronization, low current applications, and tracking/positioning applications. To... read more

Innovation: Hunting for GNSS Echoes

November 1, 2013By
Figure 1. ARTEMISA simulation platform architecture.

Analysis of Signal Tracking Techniques for Multipath Mitigation
Researchers involved with ARTEMISA describe their efforts to generate synthetic multipath of GPS L1 and Galileo E1 signals and to test different signal tracking techniques in a simulated receiver to see which techniques best minimize the effects of multipath on positioning solutions. read more

This article is tagged with , , and posted in Design & Test, Innovation

On the Edge: Multipath Measures Snow Depth

November 1, 2009By
FIGURE 2. Snow depth derived from GPS (red squares), the three ultrasonic snow depth sensors (blue lines), and field measurements (black diamonds). Bars on field observations are one standard deviation. GPS snow-depth estimates during the first storm (doy 85.5–86.5) are not shown (gray region) because the SNR data indicate that snow was on top of the antenna.

The September “Innovation” column in this magazine, “It’s Not All Bad: Understanding and Using GNSS Multipath,” by Andria Bilich and Kristine Larson (see www.gpsworld.com/multipath), mentions the use of multipath in studying soil moisture, ocean altimetry and winds, and snow sensing. An experiment the authors conducted, designed to study soil moisture, yielded a surprise bonus: a new methodology for measuring snow depth via GPS multipath. It has important implications for weather and flood forecasting, and could also bring new insight to bear on GPS antenna design. read more