The Benefit of a GPS System

What benefit will you get from GPS?

Global Positioning System is a navigational aid, funded and controlled by the U.S. Department of Defense. Since GPS systems utilize 24 satellites that orbit the earth in a grid pattern, there are always six to eight satellites that are able to communicate with any given position on earth at any given time. What this does is give the average consumer the power to find any place on earth at any time day or night. Just think of the benefits this provides for a wide variety of the public.

Some of the benefits we might receive from GPS are:

Fuel economy: If you want to maximize your fuel economy you'll need a good GPS system. Saving money at the pump as well as wear and tear on your vehicle should be one of the main reasons why you would want a good GPS system in your vehicle. Accurate driving directions not only will save you time in your daily travels, but also will save you substantial gas money when travelling from place to place. This is especially important for delivery and courier services.

Travel directions: Utilizing a GPS system will give you accurate directions for travel. Weather you are travelling locally, across country, or globally, you will get accurate direction and constant monitoring of your current position. I wouldn't think of taking another family vacation without a GPS system in my vehicle.

Recreation: Weather you are camping, or hiking, a hand held GPS unit will benefit you. I can't imagine going camping in the middle of the woods and not being able to find my way out. The news is filled with daily reports of people (or kids) that go hiking in the woods or the desert, and can't find their way back home or to their campsite. A GPS unit is the answer for these people.

Maritime: If you have ever watched one of the popular fishing shows on T.V., or are a fisherman or sailor yourself, then you know how a GPS unit will benefit you. Getting lost at sea or on a large lake would not be fun. The other side of the coin is the fisherman, say there is a great hotspot on any given lake in the world, that specific spot can be saved in your GPS system and found again at any time. This could be beneficial to the recreational or professional fisherman.

Tracking: If you run a courier business, rental business, or just plain delivery service, and need to keep track of several vehicles, then GPS is what you need. Keeping track of your vehicles will keep your overhead down. The other end of tracking is keeping track of a family member or child, a GPS tracking system will aid in your efforts.

Source: Donald Buske

Garmin 12XL

I bough Garmin 12XL around 11 years ago, this is one of my favorite vintage GPS. At year 2000, I bough the high end version of 12 series; Garmin 12MAP, its look so “hi tech” at that time, and then I realized that a gps map is not available in my country. However, I still like my 12XL and still used it for backup gps. Even though Garmin has stop the production of 12xl couple years ago, I still find some shops selling this GPS with price ranging from US$ 150 up to US$ 180.

The GPS 12XL is all about performance. It features a 12 parallel channel receiver for fast satellite aquisition and tight satellite lock — even under tree cover. More than just an ultra-reliable receiver, the GPS 12XL is loaded with navigation information including 106 map datums and 7 grid formats, plus advanced orienteering features like user datum/UTM/and user grid formats to define your own map parameters. Store your position as one of 500 waypoints or add it to any of 20 routes. The proximity waypoint feature gives advanced warning of nearby hazards, while the position averaging function helps get the best fix possible.

Packed in a rugged case to handle tough conditions, the GPS 12XL uses an ergonomic rocker keypad for easy one-hand operation and features a user-friendly operating system to keep you on the move instead of pushing buttons. Four AA batteries provide up to 24 hours of use, and a variety of accessories can be added like an external antenna and mounting bracket. With the GPS 12XL, getting there won't be half the battle — it'll be half the fun.

Together with my Garmin 75, Magellan 5000 and Garmin 45xl; 12XL and 12MAP become my vintage GPS collection.

WAAS, what is it?

The below article was copied from Garmin site, should be remind in our mind that the WAAS facility is available in North America in some country which have the similar program like WAAS only, so don't expect that your GPS with WAAS capability will give more accurate measurement when use it outside of North America.

You've heard the term WAAS, seen it on packaging and ads for Garmin® products, and maybe even know it stands for Wide Area Augmentation System. Okay, so what the heck is it? Basically, it's a system of satellites and ground stations that provide GPS signal corrections, giving you even better position accuracy. How much better? Try an average of up to five times better. A WAAS-capable receiver can give you a position accuracy of better than three meters 95 percent of the time. And you don't have to purchase additional receiving equipment or pay service fees to utilize WAAS.

The origins of WAAS
The Federal Aviation Administration (FAA) and the Department of Transportation (DOT) are developing the WAAS program for use in precision flight approaches. Currently, GPS alone does not meet the FAA's navigation requirements for accuracy, integrity, and availability. WAAS corrects for GPS signal errors caused by ionospheric disturbances, timing, and satellite orbit errors, and it provides vital integrity information regarding the health of each GPS satellite.

How it Works
WAAS consists of approximately 25 ground reference stations positioned across the United States that monitor GPS satellite data. Two master stations, located on either coast, collect data from the reference stations and create a GPS correction message. This correction accounts for GPS satellite orbit and clock drift plus signal delays caused by the atmosphere and ionosphere. The corrected differential message is then broadcast through one of two geostationary satellites, or satellites with a fixed position over the equator. The information is compatible with the basic GPS signal structure, which means any WAAS-enabled GPS receiver can read the signal.

Who benefits from WAAS?
Currently, WAAS satellite coverage is only available in North America. There are no ground reference stations in South America, so even though GPS users there can receive WAAS, the signal has not been corrected and thus would not improve the accuracy of their unit. For some users in the U.S., the position of the satellites over the equator makes it difficult to receive the signals when trees or mountains obstruct the view of the horizon. WAAS signal reception is ideal for open land and marine applications. WAAS provides extended coverage both inland and offshore compared to the land-based DGPS (differential GPS) system. Another benefit of WAAS is that it does not require additional receiving equipment, while DGPS does.Other governments are developing similar satellite-based differential systems. In Asia, it's the Japanese Multi-Functional Satellite Augmentation System (MSAS), while Europe has the Euro Geostationary Navigation Overlay Service (EGNOS). Eventually, GPS users around the world will have access to precise position data using these and other compatible systems.

• 100 meters: Accuracy of the original GPS system, which was subject to accuracy degradation under the government-imposed Selective Availability (SA) program.
• 15 meters: Typical GPS position accuracy without SA.
• 3-5 meters: Typical differential GPS (DGPS) position accuracy.
• less than 3 meters: Typical WAAS position accuracy

Basic navigation for GPS

The sketch above provide a graphic illustration of the navigation terms used by basic Garmin GPS unit.

GPS Basic Information

The worldwide Global Positioning System (GPS) network was designed by the US Department of Defense, as a way to track one’s exact location anywhere in the world.

The GPS network consists of 24 navigation satellites, which orbit the planet at a height of approximately 12,000 miles. These satellites each orbit the earth twice every 24 hours, and they are set up in such a way that they can send signals to any location on the planet, whether it be land or sea, and no matter how remote.

The 24 GPS satellites are continuously beaming positioning data, which can be picked up by GPS devices on the ground, and used to calculate exact latitude and longitude coordinates. Depending on the device that is used, this data can be accurate to within a few meters.

Some GPS devices also provide advanced features such as dynamic mapping and detailed driving directions.

Despite the common misconception that GPS-enabled devices are prohibitively expensive, and only useful in scientific and military operations, many of these useful gadgets are primarily designed with the consumer in mind. For example, GPS handhelds can be carried around on one’s pocket, and are very useful for a number of functions. Certain companies, have even integrating GPS technology with common consumer products such as mobile phones