Creating Custom Topographic Maps for your Hand Held GPS Unit - Part 3

This is Part 3 of a multi-part series on creating custom topographic maps for your hand held mapping GPS unit. For previous posts click one of the following:
Creating Custom Topographic Maps for your Hand Held GPS Unit - Part 1
Creating Custom Topographic Maps for your Hand Held GPS Unit - Part 2

---

Creating Custom Topographic Maps

for your Hand Held GPS Unit - Part 3

Manipulating Topographic Data

In the last post, Post #2, we downloaded topographical data from the USGS Seamless server. The data we downloaded is in the GeoTIFF format, and while it looks pretty cool, we need to convert that from a shaded picture to contour lines.

Pretty groovy, but you can't go orienteering with it.

To change that mess up there into contour lines we are going to use the FWTools software that we installed way back in Post #1, so please keep reading after the jump.

Creating Custom Topographic Maps for your Hand Held GPS Unit - Part 2

This is Part 2 of a multi-part series on creating custom topographic maps for your hand held mapping GPS unit. For previous posts click one of the following:
Creating Custom Topographic Maps for your Hand Held GPS Unit - Part 1

---

Creating Custom Topographic Maps

for your Hand Held GPS Unit - Part 2

Finding and Downloading Data

In Part 1 we discussed the steps required to produce a topographic map for a mapping GPS unit and the tools we will use. In this post I will walk you though the process of downloading data from the internet.

For this tutorial I am going to create topographic maps with hydrography data. These maps will overlay the existing maps in your GPS unit, this way, if you have Garmin Street Navigator maps, you will still be able to see the Garmin Data beneath your custom map. I will eventually post an advanced How-To that includes the shape files for park boundaries, but this requires quite a bit more work and is not necessary for creating a basic topographic map.

Step two in our process is downloading data. We will start with the topographic data from the USGS after the jump.

Creating Custom Topographic Maps for your Hand Held GPS Unit - Part 1

Creating Custom Topographic Maps

for your Hand Held GPS Unit - Part 1

A Brief Introduction

So you just bought yourself that hand held GPS unit that you've been wanting. It looked so good in the store and it came in a very nice box with impressive and professional looking graphics on the outside. You, of course, pay little mind to the box as you open it up and extract your new toy. A mapping GPS unit! Now you have the power to always know just exactly where you are at all times and it fits into the palm of your hand!! Hurriedly you turn the unit on only to discover... the damn thing doesn't have hardly any detail on the base map. Now what?

Shiny and at the moment, useless.

Well Garmin is hoping that you will purchase map packs from them. I guess it is good for Garmin, I mean, when you buy the map packs from them you end up spending half again what the unit cost just to make it... well, usable. But what if I told you that you could create accurate, custom maps for your Garmin GPS unit and all it will cost you is some of your free time? Sounds great doesn't it? Well continue reading after the jump to learn how to create your very own completely customized maps for your GPS unit.