Bathymetric Mapping of Dells Mill Pond

1
Bathymetric Mapping of Dells Mill Pond
2
Tools of the Trade
This is the Trimble GeoExplorer. It allows the
user to set data categories and use them to store
data to be transferred to the computer for use in
the map.
This is a Humminbird depth locator this is used
with the GPS to acquire water depths, which are
stored in the GPS and later put in the map.
3
More Tools
Moving about the lake is made easier by using
an electric trolling motor like this one. They
are easy to use, and starting and stopping is
very convenient.
I used a boat like this one. A flat bottom for
stability and it does not need a lot of water to
float in. The seats were handy for setting the
GPS and depth sounder on.
4
GPS
The GPS is a very unique and useful tool.
It uses satellites in space to locate a way point
on earth. These way points are then used to make
the map. There are several different steps that
must be taken to get the GPS set up before
use. 1. System Setup After the GPS has been
stored for a while it needs to find the
satellites again. 2. Enter Data Dictionary
This is a program that the GPS uses, it allows
the user to select the type of data to be saved,
whether it is, point, line, numbers, or one of
the many that are available.
5
Data Dictionary
This is an example of a Data Dictionary. The
features are on the left side, I have entered
Depths. On the right are the Attributes, for
this I have entered the depths 2,4,6. When I
crossed a depth change I would enter it in
the correct attribute.
6
Getting the Shape
The first step to the mapping process is to
make an outline of the pond. I used the GPS and
the boat to follow the shoreline. Once that was
completed I went to the computer and saved the
data for later use, with Pathfinder Office.
7
Collecting Data
Getting out on the water and actually
getting the information that is needed was the
fun part of this project. The best way that I
found was to go in a zig-zag pattern. Every time
a depth change was crossed its way point was
entered into the GPS for later use. Getting good
data is important for having an accurate map. I
worked on both ends of the pond, while doing this
I found that the north end had more
irregularities than the south end. Because of
this I had to spend more time on the north
end getting very accurate information. When I
got to the south end I was able to go over it
quickly because it didnt change very much.
8
Information Processing
The first step in getting the data from the
GPS to the computer is to select the data
transfer option. This will allow you to get the
information and start making the map.
9
Information Processing 2
This is the Data Transfer option. In
this step the files from the GPS that are to be
transferred are selected, also the place where
it is to be saved is selected. This process
transfers raw data from the GPS to the computer.
Because of government scrambling the
information must be corrected. The UFCORS is a
web site that provides the necessary
information, for correcting.
10
Correcting Files
This is the web page that is used to correct
the GPS Data. Certain numbers and
other information must be entered into the form,
then the file for correcting the files will be
sent.
11
Get Unzipped
Because the files are zip files I had to unzip
them. This was easy enough, I used the program
WinZip. The files were changed to a format that
could be used by the computer. Now I was able
to correct the data to be very accurate.
12
Formatting
Using Pathfinder and the differential
correction option along with the correction
files from the internet, all information was
corrected. This moves all data points to the
correct position, doing this makes the map
very accurate.
13
Starting the Map
Here is a sample of a map. The outline of the
shore and some of the data have been added to
the view the next step will be to add the rest
of the depths. Then every depth category will
be connected.
14
Connect the Dots
Here is the map with some of the raw data from
the GPS on the shoreline map of the pond.
There are three depths with different colors.
Connecting the dots at each color will give
depth contours for each value.
15
Getting Close
Here is the map before the final touch-up
stage some of the lines run together, and some
dont go anywhere. These are all things that
will be fixed before the final stage.
16
Wrapping it up
Here is the final map the keys have been
inserted, the depths labeled, and the
whole thing has been cleaned up. Now all that is
left is to publish it, and get it out to the
public.
17
Useful Tools
Howies Funware- This was used to take
pictures of the computer. ArcView- This
program was used in the map making process.
Pathfinder- Another mapping program. Power
Point- Used to make this presentation.