Activity 3

Introduction

                The Hadleyville cemetery mapping project is currently in its final stages. The projects goal was to create a GIS enabled map for the Hadleyville cemetery to use for plans which had been lost in a previous move. A major challenge of achieving this goal was the lack of physical records of the grave stones, so data had to be collected in person. The data that was collected was kept in a physical format(notebook), and contained all the pertinent information of the individual graves like name, DOB DOD, and title. The information in the notebook was then compiled into an excel spreadsheet and imported into the GIS map to link with our attribute table, which allows for the capability to have all the attribute information available about each grave, in a spatial map, giving the user a much more powerful tool to work with.

                The specifics of data collection can be found in a previous blog post (http://geospatialoliver.blogspot.com/ ). Overall, the data collection flow stemmed from the manual collection of grave information, and an aerial photograph taken with the Gis capable drone flown above the cemetery. The aerial image was used to then, in a heads-up display, digitize the location of each of the graves. Using the physical copies of the grave locations and information, grave stones which are under the canopy of trees can be successfully mapped and placed spatially. That is why it is of the utmost importance to have physical copies of the information, because while technology is constantly improving our lives, it always has the chance of failing. By building a GIS, around the attribute data of the grave stones, a GIS can solve the problem faced by the cemetery by including individual’s information with a map symbolizing the spatial locations of the grave.

Study Area

                The Hadleyville cemetery is located south of the city of Eau Claire, in west-central Wisconsin. The cemetery is adjacent of a large plot of corn field, and mostly consists of grass, with a few large conifers and other assorted trees around the parameter of the cemetery. Approximately 1 square acre. The data was collected mid-September, between the afternoon hours of 3-6 pm.

Methods

                This project was completed with a combination of geospatial tools. Most simply, the use of a notebook and pencil to gather the information about the grave stones and retain a physical copy. It is important for the collection of data to not only have digital information. A physical copy will next fail, or crash when a program isn’t responding. Additionally, a physical copy can always be returned to as a reference as the project moves forward.  As a compliment to that, a Drone was flown overhead to obtain an aerial image of the cemetery. This specific drone produces a very spatially accurate image, down to below a foot. This advanced technology saves a great deal of time, because the alternative was using a survey grade GPS to map the locations of the grave stones. When the data was first being collected, a survey grade GPS was used, but postponed due to the long amounts of time it took to gather each point.

                To facilitate the transfer of data from the physical copy into Esri’s Arcmap program, an Excel spread sheet use used. excel allowed for the standardization of the attribute data, which varied greatly. When the information was added into the excel, a standardized scheme of labeling had to be established. The class communicated together, and came up with a list of attribute categories which fit all the needs of the attribute data. The process of data normalization, which is the facilitation of a standardized table, produced some problems which the class had to figure around. A primary problem faced by data normalization is what to do with a grave stone which houses a family (sometimes up to six), with only one stone. In order to not exclude any names, each individual had an individual point which corresponded with attribute information. In order to make sure a plan was clearly communicated, a special category was created call notes, which illustrated which graves are attached to which, and what families are placed together. This was a problem which was clearly communicated by the class during discussion, so a cohesive GIS map could be created.

                Once the attribute data table was normalized, it could be combined with the aerial photo taken from the drone be the process of heads-up digitizing. This involves the manual collection of the grave stone locations while looking at the imagery inside of a Arcmap. The grave stone locations are collected, and integrated with the attribute data by a table join. The final product results in a spatially accurate map, which possesses a lot of attribute data. Now each point in the map, is linked to a person, and can be viewed by looking at the information of the point.

                An important aspect of why an aerial image can be used, comes with the advancement of lowing the pixel size so that incredibly accurate information can be collected, directly from the image, because it already is in a projected coordinate system, with a consistent scale throughout the image.

Results

Figure 1: This displays the GIS map which was created. The graves are located by the yellow dots, with a locator map in the lower left corner. 

Figure 2: The final spreadsheet used to attach the attribute data with the points in the GIS.

Figure 3: This image displays the information table which appears
when a data point is selected. Showing the options of information
available.

Our data collection methods needed some refining. Our class was quite unorganized when we initially got out to the site. Several groups of students went off in different directions without a cohesive plan for data collection. This caused for data points to be missed, and attribute data to be miss appropriated to the wrong locations. To remedy this situation, the entire class got together and had a dialog about what specific goals for the project, and individual tasks for people to take. This produced the desired outcome, as the students began to have an open conversation about the project, which was very important when it came time to normalize the data.

                Another facet of the methods which increased the data collection was the complicated, survey grade GPS. This device, can accurately map within the cm, but does have some short fallings, like time to collect each point, and the poor reliability for points under tree canopies. This latter problem, is what caused the most problems with the collection of data. That is why an aerial image was taken from the drone, which greatly decreased the time needed to collect each of the gave stone locations.

Conclusion

                The methodology used was distinctly planned to follow exactly what was needed in the final product. By using a drone to collect the spatially accurate image, and the manual collection by multiple students made the process go much faster. Although, there is great potential for data errors when collecting in the manual way, it allows for the easy manipulation and correction of the error. If the greatest potentials for error are monitored, and several QC checks are done throughout the process, the data error will be essentially null.

                As the project comes to its conclusion, it’s important to evaluate the end product which is going to be delivered. The product which is finalized, offers a successful comprehensive survey of the Hadleyville cemetery, locating each grave stone in residence, and producing a GIS which can be added onto simply and efficiently. This provides a great service to the county, which is now able to electronically keep up with its occupancy, and add information much more easily then every before. The spatially accurate map, contains a great deal of attribute data, which combined with the spatial locations of each grave is a valuable end product which will follow into the future.