As of 2010 the GPSMAP 60CSx is considered by many enthusiasts to be one of the best all-around handheld GPS unit available on the consumer market today.

The GPSMAP 60CSx is an upgrade of the GPSMAP 60CS, one of the best selling handheld GPS units for outdoor and marine use. This unit features a removable microSD card so you can expand the mapping memory. This has been one of the most requested features by Garmin customers and is reason enough to upgrade from the GPSMAP 60CS. The microSD card slot is located inside the waterproof battery compartment and users can load map data and transfer routes and waypoints through the unit’s fast USB connection.

Perhaps the most exciting feature of the GPSMAP 60CSx is the new, highly sensitive, third-generation GPS receiver chip by SiRF. This SiRFStar III chip locks on to satellite signals faster and lets users track their position in more challenging conditions like heavy tree cover or deep canyons. The GPSMAP 60CSx also features a barometric altimeter for accurate elevation data and an electronic compass that can be used while stationary.

The GPSMAP 60CSx sports a large color TFT screen and turn-by-turn routing. Each unit ships with a blank 64 MB microSD card. It is possible to purchase new microSD cards that are pre-loaded with MapSource Topo and inland lake maps, BlueChart marine cartography, and City Navigator street maps. You can also take advantage of the removable microSD memory and upload map data to a blank card from your PC. The contains maps of all of the USA on one CD for not much more than just one section of the country on a preloaded microSD card.

Garmin GPSMAP 60CSx Portable Navigator – 2.66 Active Matrix TFT – 12
Price: $380.18
The gpsmap 60csx portable navigator is one of most popular models for outdoor and marine use.  It contains a removable microsd card for detailed mapping memory and a waterproof rugged housing. The microsd card slot is located inside the waterproof battery compartment. It features a new highly sensitive gps receiver that acquires satellites faster and lets users track their location in challenging conditions such as heavy foliage or deep canyons. Owners of new x-series handhelds can also purchase new microsd cards that are pre-loaded with mapsource topo and inland lake maps, bluechart marine cartography, and city navigator street maps.

What is GPS? GPS stands for Global Positioning System. It is a satellite radio navigation system built by the United States Department of Defense. Research on the system began in the 60’s and the first GPS satellite was launched in 1978. It took a while for the entire system to come online but finally on April 27, 1995 it became fully operational. At first, the GPS network was only for military use but in the 80’s the United States government authorized the general public to make use of it too.

The GPS System is composed of:

• Satellites
• Earth Monitoring Stations
• GPS Receivers

What Is a GPS Satellite?

There are currently 24 satellites orbiting the earth in 6 distinct trajectories. Each satellite completes two orbits around the earth each day, traveling at a speed of about 7,000 MPH. At the highest point in their orbit they are more than 12,000 miles above the earth. From this height, the satellite signals can be received over a large percentage of the surface of the earth. A GPS unit works by receiving multiple satellite signals and calculating the receiver’s position based on triangulation of the different signals. Accuracy is increased with each additional satellite signal that is received so the orbits of the satellites are set so that at most points on the earth there are at least 4 signals that can be received. Of course, this is in theory only since the landscape around you can block some or all of the GPS signals.

What Is a GPS Earth Monitoring Station?

There are four unmanned monitoring stations in the US and one manned master station which is located in Colorado Springs, Colorado. The four unmanned stations relay position data from the satellites to the master station. The master station uses the relayed information to correct the position of the sat tiles and sends the corrected information back to the satellites. This synchronizes the data that each satellite transmits to your GPS receiver and ensures that your receiver is always working with accurate information.

What Is a GPS Receiver?

GPS satellites transmit low power radio signals that can only be picked up if your GPS unit has a direct “line of sight” to the satellite. The signals can penetrate things like glass, plastic and clouds but not solid structures like buildings or rocks. A GPS unit works by triangulating your location based on the position of at least three satellites in the GPS system. It compares the time it takes to receive a signal from each of the satellites in range and calculates your location based on the data.

If you are only able to pick up three satellite signals, your GPS unit can report your location in latitude and longitude. However, when the GPS unit picks up signals from at least four satellites it also calculates your altitude. Now it can report your trip distance, distance to a destination, travel speed and even your altitude if your GPS receiver features an altimeter.

How accurate a GPS unit is depends on its ability to find and lock onto a satellite’s signal. As you might expect, you get what you pay for and the more expensive GPS units are generally more accurate. The best consumer units claim accuracy to within a few feet while the older or less expensive units can be off up to 30-40 feet or more. Where you plan to use your GPS receiver could determine if it’s worth shelling out the extra money for increased accuracy. If you’re using your GPS unit in flatter terrain with a good open view of the sky a less expensive unit could perform nearly as well as the top of the line receiver. However, if you plan to use your receiver in dense tree cover, while hiking in ravines or narrow valleys, or among tall buildings you’ll gain much better accuracy with a more higher end GPS unit.

Now you know the basics about how GPS works and can answer the question “What is GPS?”.

The answer to this question keeps changing along with advancing technology as well as United States law. The first consumer GPS receivers on the market were far less accurate than the receivers available today even though the satellites are the same. Also, before the year 2000, the military intentionally introduced inaccuracies into the civilian GPS signal for “security” reasons. They called this intentional signal error “Selective Availability”. In May of 2000, President Clinton made a decision to turn off SA and allow civilians access to increasingly accurate GPS signals. The military still has the ability to turn off or introduce errors into GPS signals at any time and with no notice but this ability is generally only used for specific reasons of national security.

The best consumer GPS technology available as of 2009 achieves an accuracy level of 15 to 30 feet under normal conditions. Garmin, currently the most popular manufacturer of GPS receivers, claims their GPS units are accurate to within 50 feet 95% of the time. Even within the Garmin GPS receiver line, accuracy specs differ because of the different chips used in the design of different receivers.

GPS Receiver Design Affects GPS Accuracy

If you are looking for the most accurate consumer GPS unit, it’s important to pay attention to the unit’s chip type. The latest technology in GPS receiver chips is the SiRFStar III from SiRF. With this chip in your receiver and WAAS enabled you can expect to reach the best GPS accuracy levels available under current conditions.

Environmental Factors Affect GPS Accuracy

Many different environmental factors can also affect the accuracy of your GPS receiver. Heavy tree cover, tall buildings, deep canyons, and any location in which your view of the sky is limited can affect how accurate your GPS is. Atmospheric conditions can also degrade the accuracy of your GPS unit.

As you can see, there is no easy answer to the question “how accurate is GPS?”. However, you now know the main factors that can affect GPS accuracy.