Quick Start Guide for GPS150USB V1.01
TEL + 44 1179 554474 www.digitalyacht.co.uk sales@digitalyacht.co.uk
1. Introduction
Congratulations on the purchase of your GPS150USB Smart GPS/GLONASS Sensor. This product is designed for simple
and easy “plug and play” operation and “Do It Yourself” installation. If you want to permanently mount the GPS150USB,
then you will need to purchase a suitable 1” x 14 TPI thread mounting bracket or some M3 Nuts and Bolts.
Knowing your position whilst at sea is key to safe navigation. What we now take for granted, was extremely difficult, time
consuming and inaccurate. Then, in the latter half of the 20th century, came the electronic positioning systems –Decca,
Loran, Transit and in the 1990s, the global positioning system, GPS. Over 20 years have passed since the first GPS
receivers were commercially available and in this time the whole world has come to rely on this US funded technology.
Now every boat, plane, car and train that we travel on has GPS navigation and even your smart phone can give a GPS
position accurate to within 10m, anywhere in the world, at the touch of a button.
Much political discussion has taken place over our reliance on GPS technology, to the point where both Europe (Galileo)
and China (Compass) are developing their own satellite based navigation systems, which are scheduled to be fully
operational by 2020. However, whilst GPS was being developed in the 1980s, there was another competitive system
developed in Russia called GLONASS. This system was very much over shadowed by the American GPS system and
due to the secrecy surrounding the technology and the difficulties for non-Russian companies to license this technology, it
never achieved wide spread commercial use outside of Russia and surrounding countries.
During Russia’s difficult financial period between 1989-1999, government spending on their space program was cut by
80% and launching of new GLONASS satellites stopped. With relatively short life spans the GLONASS satellites soon
started to fail and by 2001 there were only 6 satellites still operational and the GLONASS service effectively ceased.
Most observers at the time thought this would be the death of GLONASS but in 2000, with the Russian economy
recovering, President Vladimir Putin took a special interest in GLONASS and made the restoration of this service a high
priority. Between 2002-2011, a large investment was made and at the end of 2011 GLONASS was fully restored and now
offers worldwide coverage (with 24 operational satellites) and accuracy almost as good as GPS. In areas of high
Latitudes (North and South) GLONASS is more accurate than GPS due to the orbital position of the satellites.
Now with the GPS150USB DualNav™ technology, boat owners can have a single sensor that will automatically read
satellite data from both GPS and GLONASS constellations, choosing the best signals from over 50 satellites. Wherever
you are in the world you now have twice the satellites to choose from resulting in the GPS150USB receiver having much
better coverage, time to first fix and positional accuracy. Add to this the new high sensitivity receiver design, selectable
baud rate and 10Hz position update rate and you have a GPS receiver that is significantly better than every previous
marine GPS receiver on the market.
The new performance is particularly noticeable if the receiver is mounted below deck/inside the wheelhouse where the
high sensitivity receiver still gives a good position fix or when there are obstructions blocking the view of the sky, such as
a wet sail shadowing the antenna or when sailing in rivers or close to cliffs, plus DualNav™ technology with more
satellites to choose from, gives a much more accurate fix.
On larger boats, it is now possible to have two completely separate position sources, not just two GPS units but two
different positioning systems so that you can compare and validate your actual position. Set one GPS150USB to GPS
mode and another GPS150USB to GLONASS and you have dual redundancy and two independent positioning systems.
The GPS150USB also supports SBAS (Satellite-Based Augmentation System) which is the generic name given to the
differential signal transmitted by various local geo-stationary satellites. SBAS allows the GPS150USB receiver to remove
errors in the position due to environmental conditions and improves accuracy down to <1m. Using WAAS in the US and
EGNOS in Europe the GPS150USB will automatically switch to differential SBAS mode when available.
The GPS150USB will also be able to utilise, with a software update, the European funded Galileo positioning system
when it comes on line (IOC –Initial Operation Capability) in 2018.
Before operating the unit you should also familiarise yourself again with the user manual of the
Navigation Software that you will be using the GPS150USB with. Pay particular attention to the GPS
Interfacing section and any settings that need to be configured for correct operation.
