Receiver Design

Expert Advice: BeiDou, How Things Have Changed

February 1, 2013By

Economically, the System Differs Significantly from Its GNSS Cousins John W. Lavrakas In May 2007, I authored an article in GPS World looking ten years into the future and envisioning how the GNSS field would operate at that then-distant time. Reviewing my assessments, I see that I was both accurate and wide of the mark with my predictions. The prediction... read more

Signal Decoding with Conventional Receiver and Antenna

February 1, 2013By
Figure 7  Signal-to-noise-density ratio of E1 (red), E5a (magenta), E5b (blue), and E6 (green) code tracking of Galileo IOV satellite PRN 11 on December 21–22, 2012.

A method of decoding an unknown pseudorandom noise code uses a conventional GNSS antenna and receiver with modified firmware. The method was verified using the signals from the Galileo In-Orbit Validation satellites. read more

Septentrio Demonstrates BeiDou+GPS+GLONASS Positioning

January 9, 2013By

Septentrio announced on January 7 that it has successfully implemented BeiDou support in the company’s high-precision receiver software, taking advantage of the recent official release of BeiDou’s Interface Control Document (ICD) to including the Chinese satellite navigation signals into its position-velocity-time (PVT) solution. According to the Belgian GNSS receiver manufacturer, its engineers “are currently processing further data sets to finalize... read more

Retired GIOVE-A Helps SSTL Demo High-Altitude GPS Fix

November 30, 2012By
Galileo's GIOVE-A retired in June 2012

An experimental GPS receiver, built by Surrey Satellite Technology Limited (SSTL), has successfully achieved a GPS position fix at 23,300 kilometers altitude – the first position fix above the GPS constellation on a civilian satellite. The SGR-GEO receiver is collecting data that could help SSTL to develop a receiver to navigate spacecraft in geostationary orbit (GEO) or even in deep... read more

What Is Achievable with the Current Compass Constellation?

November 1, 2012By

Data from a tracking network with 12 stations in China, the Pacific region, Europe, and Africa demonstrates the capacity of Compass with a constellation comprising four geostationary Earth-orbit (GEO) satellites and five inclined geosynchronous orbit (IGSO) satellites in operation. The regional system will be completed around the end of 2012 with a constellation of five GEOs, five IGSOs, and four... read more

This article is tagged with , and posted in BeiDou/Compass, GNSS, Receiver Design

Innovation: Software GNSS Receiver

September 1, 2012By

An Answer for Precise Positioning Research
In this month’s “Innovation,” we look into the development and capabilities of one modern software GNSS receiver in an effort to answer the question “What is the ideal GNSS receiver for precise positioning research?” read more

This article is tagged with and posted in From the Magazine, Innovation, Manufacturing, Receiver Design

Low-Complexity Spoofing Mitigation

December 1, 2011By
Figure 3. Null steering toward the spoofer signals.

Most anti-spoofing techniques are computationally complicated or limited to a specific spoofing scenario. A new approach uses a two-antenna array to steer a null toward the direction of the spoofing signals, taking advantage of the spatial filtering and the periodicity of the authentic and spoofing signals. It requires neither antenna-array calibration nor a spoofing detection block, and can be employed as an inline anti-spoofing module at the input of conventional GPS receivers. read more

This article is tagged with , and posted in GNSS, Receiver Design, Signal Processing

Consumer GPS/GLONASS: Accuracy and Availability Trials of a One-Chip Receiver in Obstructed Environments

December 1, 2011By

A one-chip multiconstellation GNSS receiver, now in volume production, has been tested in severe urban environments to demonstrate the benefits of multiconstellation operation in a consumer receiver. Bringing combined GPS/GLONASS from a few tens of thousands of surveying receivers to many millions of consumer units, starting with satnav personal navigation devices in 2011, followed by OEM car systems and mobile phones, significant shifts the marketplace. The confidence of millions of units in use and on offer should encourage manufacturers of frequency-specific components, such as antennas and SAW filters, to enter volume mode in terms of size and price. read more

This article is tagged with , and posted in GNSS, Receiver Design, Uncategorized