High quality maps for your GPS unit

Google Earth-type maps arenít worth the effort

Captain Paul Titus

May 01, 2012 at 4:16 pm  | Mobile Reader | Pring this storyPrint 

You can spend all your time changing out GPS chips to have the best maps, or you can use that time to fish.
You can spend all your time changing out GPS chips to have the best maps, or you can use that time to fish.
Dear Capt. Paul:

My Garmin GPSMAP 60csx has some downloaded maps from Garmin MapSource TOPO 1:100,000, but these maps arenít very good for marsh fishing. My Blackberry cell phone gives me Google Earth, but it wonít stand up to rain/pounding and it doesnít work where there is no cell phone service. Is there a way to get Google Earth maps on my map60csx?

Is there any handheld that gives Google Earth quality maps? If not handheld, then can you recommend a smallish fixed mount unit with Google Earth mapping?

Thanks in advance for this answer and thanks for all I have learned from your posts over the years.

littlewing

Capt. Paulís response:

First a little background on your question:

Google maps are available from and through the Google Earth Internet server. To access these map images, you need to be connected some way to the World Wide Web, the Internet. This could be by either an Internet land line, WiFi or via a cell or smart-phone connection.

These Google maps are "raw" U.S. Geological Survey images. They are NOT ortho-images, as a normal USGS topographical or NOAA Marine chart would be. They have NOT been corrected to a map datum. That means that the actual position as shown on the Google images in your call phone may not be actually where it is shown. The maps are close but not as accurate as a normal GPS-only unit.

In addition, cellular and smart phones do have a GPS receiver built into their configurations, but they do NOT have the accuracy of a modern GPS receiver. New GPS units can add to the GPS signals by utilizing the WAAS differential signals. A GPS unit with the WAAS activated can discern a position to within a 3-meter (9.8 feet) radius. Most smart phones can only determine a position to within a 20-meter (65.6 feet) radius. That is why you see a circle around the position on your smart phone; it is letting you know that the actual position could be somewhere within the drawn circle. The accuracy could easily be up to 100 feet off.

As you move over the area with your smart phone active with a Google Earth-connected GPS program on, the phone electronically requests an aerial view from the Google map server around its position. The unit accesses the server, requests another map image and displays it on your smart-phone screen as you move or scroll to a different position.

The Google server has literally hundreds of thousands of such aerial images in its vast files. These images are stored in a massive memory bank and displayed on your device.

But remember, the cell phone MUST access the Google server either by a landline, WiFi or a wireless phone connection in order to ask for and receive the changing images.

Many outdoor locations do not have Internet or even cell phone service. Without such a connection you will not get a map image. You could even find that your cell phone dropped your connection because of the amount of users at that time or because you have wandered away from the telephone providerís cellular range.

The topographical map you indicated that is in your GPS unit is, as you said, in 1:100,000 scale. If that does not meet your needs, check out the Garmin TOPO U.S. 24K Southeast DVD. These maps are in 1;24,000 scale, the same as a standard topo or "quad" map.

The southeast disk covers most of the Southeast states from Louisiana to Georgia and Florida. It consists of 1:24,000-scale Topo type maps for the area. A part of the coverage can be used in the GPS unit via means of a memory card.

The program is listed on the Garmin web site at $149. The site allows the user to actually see the map and zoom in of a specific area. This is exactly what you should do to see if it meets your needs before you plunk down a yard and a half of your money.

I believe that the Garmin GPSMAP 60csx is an excellent GPS unit; I own one. The unit can accept Garminís BirdsEye mapping by subscription as a download, in additional to the aforementioned topographical mapping programs. The BirdsEye Satellite Imagery is a paid subscription service that lets you download satellite images to your device and integrate them with your maps in your GPS unit.

These images, both the Topographical and BirdsEye "maps" are loaded onto a memory card, which is placed in the GPS unit. That means that the unit can access only the map images that are on the memory card.

Depending on the size of the required data for the maps, itís possible to travel off the area of coverage that is installed in your GPS unit. The SD (micro) card can only hold so much data as map images. You will NOT be able to install all of Southeastern United States in your GPS unit at one time.

But, with several data cards you can download from the DVD or computer download different areas of coverage.

Photo-type images, as these aerial view maps are, require a lot of memory space. The size of the map downloads are determined by the size of the SD data card and the configuration of the unitís operating software. Coverage in aerial view maps for an area that is 5 by 10 miles (50 square miles) in width and length may take up to 8 GB of memory. Many GPS units cannot read cards of that size.

Normally, you would not run off of the topographical map coverage, but a power boat with a 60-mile range could easily run off the aerial maps stored on the SD card in a GPS unit. This is not normally a problem with a hiker or hunter because they wouldnít usually be able to walk out of the saved map coverage.

The advent of travel by means of power changes the viability of such aerial mapping. A unit on or in a vehicle can easily travel out of the existing aerial photo map that is on the memory card in that unit.

It could take 10 or even 20 8GB to 12GB data cards to cover your fishing experience from the launch to your fishing areas and back for one dayís trip. Using this technique would require that you carry and mark each memory card with the area of coverage. You would have to ensure that the cards are protected from the weather, heat, electronic interference and other contaminants that you may encounter.

You may not mind fiddling with the mapping cards, but I would rather be fishing.

I suggest you contact the Garmin Support section at (800) 800-1020 and be sure that the 1:24,000 topo and the BirdsEye programs will run in the GPSMAP 60csx unit. These two mapping programs may solve your mapping concerns. If the Birdseye program will work, get it and load only the specific fishing areas you need on one memory card.

And as you noted, the smart phone is not weather and impact protected, and it MUST be connected to the Google server to get any map images. The GPS unit, however, is made to withstand jostling and hostile weather.

So use the GPS unit when out and about.




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