I’ve been waiting for good weather to go back out bike riding with my GPS since the last post, but unfortunately the wind where I live is so strong that nearly blows me over walking! So, while it looks like I won’t be able to get you any photos from the field, I can still talk about the GPS itself and show you how it works.
This article isn’t meant to be a thesis, just an introduction to GPS and the Garmin eTrex Vista C in particular.
GPS is an acronym for Global Positioning System and the term is often used to refer to a GPS receiver. The GPS system itself was designed and implemented by the US DoD and is free for everyone in the world to use (to those US-haters who complain about everything the US does, “you’re welcome“). I call the receiver units “GPS” along with everyone else. Modern hand-held GPS units are a marvel of technology, performing very complex calculations to provide a position solution based on Doppler shift offset information received from the orbiting satellites. The main GPS satellites are not geo-synchronous and for good reason. If you happen to be in a place that suffers from poor reception, all you have to do is wait for 10 or 15 minutes and the satellites will move to new positions and eventually you will be able to receive the signals. In practice this system works remarkably well.
The former Soviet Union also has their own system, called GLONAST and in the early days of civilian GPS use I remember seeing dual units costing thousands of dollars. I haven’t bothered to even research the Russian system and see if its still operational since the fall of the Union.
I’ve always been the kind of person to modify my gear to suit my needs. This is especially true of computers and electronic gear. I do this with pretty much everything I own. My TV audio has a custom-equalized setting that I created. My Nikon digital camera has a completely custom program. All my ham gear was modded to death. My bicycle is customized. So, naturally nothing about the operation of my GPS is stock. This model GPS is very highly customizable, enabling the user to not only select what screens of information are available, but to even select the information displayed in virtually every data field per screen. Since I have been using GPS units since 1994, and have extensive experience using Garmin units, I know exactly what I want displayed and under what conditions. I will attempt to show you a little about how this model functions and how I have the difference screens and data files set up in mine. Pressing a button on the GPS scrolls through all the pages, in sequence.
Navigation among the pages and menus is accomplished by a 5-way joystick, very similar to the control you find on many mobile phones. You move up/down, left/right, and push down on the button to select.
The most prominent aspect of this GPS is its ability to display a moving map of your location. In addition, the GPS is capable of routing a path between points and draw the route on the map for you. It also alerts the use to upcoming turns and names streets.
This screen capture shows the GPS in action. We are looking at the Map page. The pink line is a route and it looks just like a map looks if you were to use a highlighter pen and draw a route on it. Immediately above the map is an information field that shows the street names as you progress along the route. Notice how this GPS integrates both English and Chinese languages. I always display maps in North up orientation. This means that North is always towards the top of the map.
As you approach turns, the unit displays the upcoming turn. The black triangle is your current position. Notice the North indicator in the upper left hand corner. No matter how you have your map set to display, this page always shows the upcoming turn Course up. This prevents misunderstandings about which way you should turn. You literally follow the arrow in the same physical direction. No matter what page you are viewing, when its time to turn, this turn indicator page will come up. After you complete your turn, it will display whatever page you were looking at before the turn. Cool.
The next page is the Compass page. The Vista C is equipped with an actual flux-gate compass which enables you to get a bearing while standing still. In the old days you had to move before the GPS could tell you in which direction you were moving. Nowadays you can use the GPS just like a compass. You can even use is as a sighting compass and project a waypoint in the distance. Very useful.
The digital compass eats batteries. You can turn it on and off at will with a single button press. Unless I am connected to external power, or actually using the compass, I keep it off. Huge difference in battery life.
Have you ever had someone travel with you who was freaking out because they thought you would arrive late at your destination? Well, this page is just what you need. Not really a map, so you won’t get any “suggestions” from someone looking at it, but it can tell you the most vital answers to the most annoying questions, such as “What time will we get there?” or “How far is it?” and my personal favorite “What is the next turn we are looking for?” Ordinarily visible only from the main menu, I have added this page to the regularly displayed list of pages. I chose these data fields specifically for the “panic” attack that sometimes accompanies travel.
3D GPS position solutions include a rough altitude calculation. Its never been considered to be accurate enough to say, land an aircraft based solely on the altitude solution provided by GPS data. For this reason, most higher-end GPS receivers have a barometric altimeter. The Vista C is no exception. The cool thing about a barometric altimeter is that, well, its a barometer. So if you are staying in a base camp for a few days, or you are operating at the same altitude, you can use the barometric pressure data to determine if a storm is approaching. Again, quite useful when you are in the field! This particular model records the data and you can browse the histogram. It can even record the data when it is turned off! You could wake up in the morning and review the overnight barometric pressure data and make a determination about the weather that could impact your activities for that day.
This is a Trip Computer page that I setup to give me what I need at a glance when I am using my computerized telescope. This GPS has sun and moon phase information, as well as hunting and fishing times.
So, you are driving around and need to find the nearest 7-11. No problem! Use the Find page. Here we see Waypoints is highlighted. This is how you find all those places you marked during your travels. I will use waypoints to show you how to actually find something in the GPS.
You can select Find by Name, Select Symbol, or Change Reference. Change Reference means that you use the map to pick a new location to find the nearest objects from. Select Symbol allows you to filter the information by those little icons that represent points. Find by Name simply allows you to spell the name or find waypoints that contain keywords. Now, here is the cool part:
With the push of a single button, change to English! You can even change case by clicking on the UP arrow (underneath OK). Just navigate to the letter, press down on the joystick and you enter that letter. This works the exact same way in either language. When done, press OK. The cool thing is that every place that the GPS offers input such as this, it works the same way every time. Once you get used to it, you got it. Hui-Chen found the interface very intuitive and she has never used a GPS before. Now, every time we go out she wants to use it!
Here we clearly see all waypoints that are closest to our current position. DOMA is highlighted and we can see the distance and bearing From Current Location at the bottom. Notice the integration of Chinese and English. This model just does not care which language you use. The entire menu system can be switched between English and Chinese, not just the displayed points!
A powerful ability of any GPS unit is to guide you along a route. This page shows you the saved routes. The little car symbol indicates that this route is currently active and is being displayed on the appropriate pages.
If you simply pick a waypoint, or a POI (point of interest) from one of the menus and select GOTO, the GPS will automatically route you to that destination. However may also create and save your own routes using waypoints or POIs that you have found and saved as waypoints. Here, we see that the waypoint called FAN is highlighted. We see from the data fields at the bottom that the distance from the previous waypoint called DOMA is 10.2KM and the course is 349 degrees T(rue).
Now, as if all that weren’t enough features, there are a couple more that you should know about. Sometimes at night, the display is too bright for comfort. Let me tell you, this thing has the brightest and most beautiful color display I have ever seen – but it can be too much! When riding my bike, the display can actually reduce my visual acuity. However, there is a clever solution to this problem:
NIGHT MODE! There are a number of “themes” similar to your computer’s operation system color schemes. The GPS can automatically switch between Day and Night display modes (if you set it up to do so). This is how the night map page looks. Its really great in the dark!
There is a page that shows the satellite constellation and which ones you are receiving and where they are on a sky map. This is useful if you are in the urban canyon and need to figure out where to move for better reception. As good as GPS is, the signals don’t like solid objects.
The last thing that I want to mention is the computer interface. The Vista C comes with a cable that connects to a USB port (and of course, includes software). The Taiwan version comes with a really great topographical map of Taiwan, and a management program called Map Source. You can download all of the information that the GPS contains (except the barometric data as far as I know) and display it on your PC. You can also create waypoints and routes, and then upload them to the GPS. I have files for different areas of the world, which makes it convenient for managing waypoints. The unit can hold 500 waypoints and that is a lot of waypoints to scroll through to find the one you want. Most people use between 50 and 100 waypoints at any given time. There is no need to keep, for example, the waypoints you marked while on vacation once you get back home. Download them to the PC and then delete them in the GPS. Conversely, the next time you go back upload them and you are back in business.
I purchased the GPS, a cigarette lighter cable, window suction cup mount (excellent!) and the bicycle handlebar mount. I am extremely pleased with this product and I can recommend it without hesitation.
I guess this post ended up being more of a review of the Vista C than I had planned!