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Mapmaker Getting StartedTutorial 1a – Using the Digitizer Goals for this section:
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Download and save aerial imagery from TerraServer.com
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Digitize Lines, Points and Areas
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Save your GM8 workspace
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Export a .MP file for compilation with cGPSMapper
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Download the compiled .IMG file to your GPSr with SendMap20 Let’s get started. GM8 has the ability to load and display overlays
concurrently. This means that you may have a reference map loaded in a raster overlay, from which you can trace
or digitize features in a vector overlay.
We’ll begin the tutorial sequence working with both types of overlays. Let’s see what data we can find online for I performed a Google search for ‘ www.jacksonholewy.net/images/content/maps/map_jackson_toon.pdf
This is a typical tourist map showing local areas of
interest. It’s clearly not to scale, and it appears to have been drawn with
perspective to emphasize the nearby mountains. But it has lots of local detail
that we can use. Open this PDF file in your browser. GM8 offers a direct connection to online imagery. Click File | Download Online Imagery/Topo Maps.
Select DOQ TerraServer as the source, and in Select Area to Download, specify
Within 1 mile of address
GM8 will download your requested aerial imagery, centered on
While we’re waiting for the imagery to download, note that
certain areas of the Let’s digitize a few features. The best working arrangement
is to be able to see both the PDF tourist map of
First, we need to establish a reference point between the
two maps. We’ll find highway 89 and trace its route through town. In the aerial
image, there is a large clear area shown just left of center, SW of the ‘ Referencing the PDF map, we can see that Highway 89 enters
from the SW, turns east into town, then exits north just before the Click at the point where the highway enters the aerial image
on the west side, then move the cursor to the point where the road curves, and
click again to add a vertex. Continue tracing the road until you reach the
intersection at the SW corner of the In the Name box, type ‘89’. In the Feature Type drop-down,
select
If you do not see black dots representing the vertices of
your road, press Shift+V to
toggle the vertex display mode. Referencing the PDF map, notice that highway 89 heads north
out of town at this intersection. We will draw another road segment for this
piece of highway 89, then join the two. Position the cursor near the top of the screen where you
completed the previous line segment. The cursor turn into an up arrow,
indicating that by clicking you will scroll the screen. Click a few times until
our Highway 89 road feature is at the bottom of the screen. If you haven’t
pressed Esc or switched to
another mode, you are still in Line creation mode. Click at the last vertex you drew, then begin a new line
going north out of town. Advanced user tip: If the cursor turns into a down arrow at the point you want to click,
press and hold the Shift key while clicking to override the scroll function. Move the cursor up to the point where the road curves NE,
and click to add a vertex. The road will continue off the screen, but your
cursor will change to an up arrow. Click while the up arrow is shown, and the
display will redraw, leaving you in the line creation mode. Continue drawing
the road until you get to the edge of the aerial image. For your last point,
right-click to terminate the line. Name the road ‘89’, the same as the other
road segment. The same road type you specified for the first road segment, ‘ Press Home to
show your entire project. Your screen should look like this:
Press Alt+D to
enter Edit mode. Click the first highway 89 segment you created, then hold the Ctrl key while clicking the second
segment to create a multiple selection. Right-click and select Combine Selected Line Features. If a
dialog pops up informing you of potentially conflicting feature values, click
YES to combine features. Press Esc
to exit Edit Mode. Your single line feature for highway 89 through A brief discussion
about labels Your Garmin GPS
receiver (GPSr) has the ability to display road names in upper and lower case,
or use accented characters … but not both at the same time. It is important to
understand this constraint early in your map design process. This constraint
does not apply to city names or area features, only line features like roads
and boundaries. If you are quite certain that you will not need an
international character set in your map, then you may use upper and lower case
in your road names. By default, GM8 creates a header specifying to cGPSMapper
that you are using the international character set, meaning that only upper
case letters may be used for street and road names. For now, I recommend that
you accept this default behavior, meaning that your street names should all be
specified in CAPS. Now we’ll add some local streets. In the PDF map, zoom into
the area around the In the Modify Feature Info dialog, enter ‘BROADWAY’ as the
Name, and select ‘ On the PDF reference map, note that The street running east-west below Broadway is called Let’s add a few more streets and then we’ll switch our
attention to Point and Area features. Add Press Alt+Z and
click-drag to zoom into the area of the jog. Press Alt+D to enter Edit Mode, and click on Millward. Right-click, then select Insert Vertex Into Selected Line. Click at the corner of the
jog. GM8 inserts a new vertex into Millward at the NE turn. Repeat at the SW
turn, and you’ve fine-tuned Millward to match the aerial imagery. Add Add Create VINE ST running north from Karns runs E-W on the north edge of the fairgrounds. Note
that it stops at Millward, then continues west one-half block south of that
intersection. We’ll define Karns in two sections. Define the first section of An important note
about road segments Earlier we defined
Highway 89 in two segments and joined them into a single line feature. Now we
have Karns in two pieces, but we can’t join them, because the street that
connects them is already defined as Millward. It is important that any given
road segment has only one name. This will be important when we add routing
information. So think of it in the way that you would give directions to
someone – “head east on Karns until it tees into Millward, turn right, then in
half a block run left onto the continuation of Karns”. Let’s switch our attention to some area features. We started
with the Teton County Fairgrounds as our reference, so let’s make it an Area
Feature. Press Alt+D to
enter Edit Mode. Right-click to select Create
New Area Feature. Click your first point at the NW corner of the
fairgrounds, at the corner of Flat Creek and Karns. Click on each of your
vertices in the roads bounding the fairground, heading clockwise around the
fairgrounds. Note that as your cursor approaches the existing vertices, it will
snap to that location, making it easier to align your area image with existing
features. Continue clicking clockwise until there is only one segment left,
just south of the intersection where you began. Right-click to complete the
Area Feature boundary. In the Modify Feature Info dialog, name this feature Teton
County Fairgrounds, and select ‘Misc. Manmade Structure’ as the Feature Type.
Add the Now let’s add some Point Features. Press Alt+D for
Edit Mode, then right-click to select Add
New Point/Text Feature. In the center of the Albertson’s is south of the Highway 89 – Flat Creek Dr
intersection. Click in the center of the large white building at this
intersection to create a Point Feature. Name the feature “Albertson’s” and
assign its Feature Type to ‘Shopping’. Press Alt+G to enter Grab Mode,
then click and drag your map to the right to show the area west of Albertson’s
and south of Highway 89. Add the Point features Add the Virginian RV Park with a Feature Type of ‘Lodging’.
Add the Cowboy Village Resort and the Snow King Lodge as lodging features. Our project is beginning to take shape. Let’s look at the
structure of the project and save it. Maximize your GM8 screen, then press Home to show the full project in your display. Press Alt+C to open the Select the TerraServer layer, then click Hide Overlay to see just your User
Created Features. Click the same button, now labeled Show Overlay, to show the aerial imagery again. Click Close to dismiss the In the File Menu, click File | Save Workspace As. Navigate to your \SAMPLE Click Ctrl+U,
which unloads the GM8 workspace. To reload your project, click File | Load Workspace, or at the bottom of the File Menu, in
the recently used file list, click JACKSON WY.GMW. If your internet connection is slow or you’ll be working
offline, you will want to have a local copy of the downloaded TerraServer data
on your machine. Let’s save a copy now. In the File Menu, click File | Export Raster and Elevation Data, then select GeoTIFF. In the GeoTIFF Export
Options dialog, select 8-bit Palette Image (PackBits/LZW Compressed). This format offers the smallest
file size with the best performance in GM8. Accept the default settings, and
click OK. Save it in your \SAMPLE MAP PROJECT\SOURCE\CITIES\JACKSON WY\ folder
as JACKSON WY.TIF. This export will take a few moments. When the save is
complete, we can reload our project with the local aerial imagery rather than
the live online data. Press Alt+C to
open the Press Ctrl+O to
bring up the File Open dialog. Navigate to the \SAMPLE MAP
PROJECT\SOURCE\CITIES\JACKSON WY\ folder. In the ‘Files of Type’ dropdown box,
select Supported Commonly Used Types.
Select Now let’s have some fun and show off some of GM8’s real
power. Click File | Download Online
Imagery/Topo Maps. In the Select Online Data Source to Download dialog,
select In the menu bar, click the 3D button at the right edge of
the control icons. GM8 renders a perspective 3D view of your project, combing
the elevation data we just downloaded with the aerial imagery and our User
Created Features draped on top. Click and drag in the 3D view to rotate the
image. Pretty cool, eh? Later in the tutorial we’ll use this elevation data to
create contour lines in our map. But first, let’s save the data for offline
access. You may have noticed that the loaded elevation data is
slightly larger than our aerial imagery, due to the different tiling sizes of
the online data sources. We can crop the data set to match the aerial imagery
before saving it. Open the Click File | Export
Raster and Elevation Data, then select Export Global Mapper Grid. Select Feet as the Vertical Units,
accepting all other default selections on the General tab. Click on the Export Bounds tab, and select Crop to Selected Area Feature(s),
and then OK. Save the file as JACKSON WY.GMG in the same directory. You can now
close the live online overlay and reload your cropped .GMG file. We don’t need the Area Feature covering the aerial imagery
anymore, so let’s get rid of it. In the menu bar, click Search | Find By Name. Unclick ‘Lines’ and ‘Points’ so that
only Areas are shown in the list. Select JACKSON WY.TIF then click Delete Selected. Close the Find
dialog, and save your project. Compiling your data Next we will export our vector data in the USER CREATED
FEATURES overlay in preparation for compiling it with cGPSMapper. In the File
menu, select File | Export Vector Data
| Export Polish MP (cGPSMapper) File. In the Polish MP Export Options,
type ‘ Now we’ll compile our exported .MP file. cGPSMapper is a
command line program, meaning that is launched from a command shell. The
simplest way to do this is to use a batch file, which we’ll create now. By default, cGPSMapper is installed at C:\PROGRAM FILES\CGPSMAPPER\CGPSMAPPER.EXE. The batch file
we’re creating depends upon this location – if your installed location is
different, adjust as necessary. Open your text editor. Create the following single line,
with the quotation marks: “C:\Program Files\cGPSMapper\cGPSMapper.exe” “ Save this file in your data directory as MAKE JACKSON
WY.BAT. Open an instance of Windows Explorer (you can use the system
shortcut keys +E). Navigate to your data directory \SAMPLE MAP
PROJECT\SOURCE\CITIES\JACKSON WY\, and double-click the MAKE JACKSON WY.BAT
file that you just created. cGPSMapper will launch with JACKSON WY.MP as its
input, creating JACKSON WY.IMG as its output. Downloading your data
with Sendmap20 We’ll create another batch file to launch SendMap20, another
program from cGPSMapper which downloads compiled .IMG files to your GPSr. Open your text editor and create the following line (with
quotation marks): “C:\Program Files\cGPSMapper\sendMap20.exe” Save this file in your data directory as LAUNCH SENDMAP.BAT.
Open an instance of Windows Explorer. Navigate to your data
directory \SAMPLE MAP PROJECT\SOURCE\CITIES\JACKSON WY\. Double-click the
LAUNCH SENDMAP.BAT file that you just created. Click the Add Maps button,
navigate to \SAMPLE MAP PROJECT\SOURCE\CITIES\JACKSON WY.IMG, and select it for
uploading.
Depending on your model of GPSr, you will either upload your
map directly, or make a GMAPSUPP.IMG file and use the Windows file system to
copy it to your GPSr.
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