GIS/GPS at Whitman Mission

Department of the Interior: National Park Service

By: Patrick Johnston


Goals and Objectives

• Develop familiarity with GIS/GPS equipment at the Whitman Mission.
• To form a basic understanding of the Arcpad software.
• To learn how to import Arcpad files into Arcview for manipulation on the desktop PC.
• To map all the trees at Whitman Mission for cataloguing purposes.
• Meet with Roger Trick weekly at the Mission site.
• To continue where the last intern left off and progress to a point where the next intern may continue.


Overall, the National Park Service seems to be a very relaxed place to be. There are many stringent government regulations to follow but there are not any bosses running around with profit on their minds. It also is not an exciting environment; it seems to be the same old thing day after day. This would be a tough place for me because I like change and variety in my daily schedule.

I have learned a few tree species I previously would not have known. Hands on tree identification make things easy. I definitely know what a black locust is now that I’ve mapped around 100 of them. I am also now familiar with silver maples, sycamores, crab apples, and honey locusts among others. With very little previous knowledge of trees outside of the Douglas fir this was an enjoyable experience for me.

I find the level of technological integration to be incredible with GIS work. GPS uses Bluetooth wireless data transfer to gather information from the GPS receiver and feed it into the pocket PC for mapping and manipulation with Arcpad software. It almost seems unimaginable where technology will go next.

I had a positive overall experience working with Roger Trick to learn GPS/GIS this semester. I think that GPS technology has endless amounts of uses that are only limited by the imagination. GPS also seems very necessary for the modern era which is only getting more complicated because it has a way of keeping track of quantitative data while having the ability to provide qualitative data with it. In our increasingly populated cities this type of mapping can and will be essential to our city to keep up on anything from trees to sewer lines and even Police officers making a spread sheet of where they gave out tickets so they can identify hot spots visually.

It is exciting to dive right into this work and learn it through field work: That type of learning sticks with me much more than reading out of a book. The understanding and use of this technology will allow the Whitman Mission to save time and money, which may then be applied to different aspects of the Mission enhancing the experience of all who visit the Mission.

The practicality of what I learned this semester is very appealing encouraging; I may be able to apply these tools directly in the future, whether it is work or hobby. This is the most valuable part of hands on internship.


I drove 15 roundtrip miles out to the Mission site weekly in my own vehicle. Thanks to the Department of the Interior I will be refunded 40.5 cents/mile. I worked directly with Roger Trick each week in an effort to further the knowledge for both him and myself. Roger also provided multiple chapters of the Arcview software manual for me to familiarize myself with. This allowed us to be more efficient in the minimal time that we got to spend together, making us much more productive in the long run.

Thanks to swift responses by both Roger and Amy Molitor via email it was easy for me to take the reins and make this internship a positive and successful learning experience. I also would like to thank Ben Schupack who interned for Roger last semester and put together a quick reference guide on how to set up and plot points using the Dell handheld PC and Holux GPS receiver. This was a very useful tool early on when I had no idea how to use the software.

Time Commitment

I went out to the Whitman Mission weekly to meet with Roger Trick. I generally went out from 1:00-4:00 on Monday afternoons. A couple times throughout the semester Roger had Monday’s off and since I had lab on Tuesday and Wednesday I went out Thursday afternoon on those weeks and spent 1:00 to 4:00 out there. This last week I had a couple meetings on both Monday and Thursday. The Thursday meeting was unexpected so I called Roger at lunch time and he said that it was not a problem. I promised to come out on the Thursday of finals week so that we can map the last few trees we have not gotten to yet. Early in the semester Roger gave me the first ten chapters to the Arcview software program and I spent time at home reading from them to familiarize myself with what I was working with. The following is my total time commitment for the semester:

-Monday 9/12- 2hours on site plus 3 hours reading
-Monday 9/19- 3 hours on site plus 1.5 hours reading
-Monday 9/26- 3 hours on site plus 3 hours reading
(*Roger was out of town this week and on Monday it was a holiday so I had to go Thursday Oct. 13.)
-Thursday 10/13- 3 hours on site
-Monday 10/17- 2.5 hours on site
Thursday 10/20- 2.5 hours on site
Monday 10/24 2.5 hours
Thurs 10/27- 3 hours
Thursday 11/3- 3 hours
Monday 11/7- 3 hours
Thursday 11/17- 3.5 hours
Monday 11/28- 2.5 hours
Thursday 12/15- 3 hours
Total on site: 36.5 hours
Total Reading: 7.5 hours
Total: 44 hours

Experience and Learning

Roger and I were very skeptical about how much we would be able to accomplish in one semester’s time. It is difficult to know how long it will take to learn a new technology. We were pretty sure that we would be able to familiarize ourselves with the software and at least begin to map and plot the trees. I set a personal goal early in the semester to map all of the trees before I finished my internship. The above map is incomplete; there are about 40 trees just to the East of center that are not mapped. However, I will be finishing mapping those; I just was not able to include it in this poster. We have a map of trees that were plotted using Bluetooth technology linking a GPS receiver to a Dell handheld PC with the Arcpad program. We created three different colors and two shapes for the trees that we mapped. We also numbered each tree and provided all the known qualitative data about it. This is now limited to species, it will be necessary to bring in a surveyor to get all the tree heights and diameters as well as condition so that they can be referenced on our spreadsheet. However, that was not part of this internship.

We accomplished many small victories with the software program that Roger may be able to use with his next intern to progress what has already been accomplished. Such battles involved: labeling our potted points, changing the font color on the map, assigning different color and shape icons to different trees, creating an excel spreadsheet with data about each tree, developing and adding new layers. Using these kinds of techniques and skills in the future the employees at the Whitman Mission may be able to develop a master map that has the accuracy of GPS which points out all the features at the Mission so tourists may be able to have an idea where they are. It can also be used to draw lines from one place to another, to measure a distance or a perimeter. I know that the Mission had a controlled burn last semester which was able to be mapped out by GPS. The possibilities are nearly endless and may be able to be stored in a single computer, instead of row after row of file cabinets.

I was able to familiarize myself with a fundamental GIS program which is used by professional geologists. This should be very useful in my future since geology is my field of study. I am excited to take my GIS course next semester here at Whitman, as it should build upon my knowledge base that I accumulated this fall and allow me to be a more functional GIS user. I am proud to say that we finished our original goal of mapping all the trees at the mission site.

Tangible final products

-Excel spreadsheet of all the trees at the Whitman Mission with at least the species
-Mapped all trees using GPS/GIS, some were previously not documented on the park and we gave them unique symbols and numbers to distinguish them.

Difficulties and Troubleshooting

As with all new technology, there is a learning curve. The Arcpad and Arcview software is no exception (Arcpad is on the handheld PC and Arcview is the desktop version which we import to). Roger and I certainly experienced multiple days where we could not make a simple change. One such day we were attempting to change the color of the font from black to something more visible on our map. It took upwards of two hours of guessing and checking to finally discover how to change the color. While we got very little done that day, it was still very successful in my mind because we leapt one of many small hurdles on our way to successfully mapping the trees. The manual to Arcview, as we discovered, is useless in problem solving. The software itself is quite different from conventional Microsoft programs that I am used to working with. This caused me to have to start from ground zero.

Roger and I found that the satellite signal that our Holux Bluetooth GR-230 GPS receiver was very weak. There is a principle referred to as dilution of precision (DOP) which indicates the accuracy that the GPS can maintain for any given moment. Through trial and error, a DOP of less than 5 will be accurate to approximately 1 meter. On most days we were able to use the receiver with a DOP of around 2 which resulted in much more efficient field work. When we plotted each tree we had the Dell Axim pocket PC average 60 points that it read over the period of about 1 minute. There were multiple days where the DOP jumped above 5 for multiple periods of time and when we plot points, for accuracy’s sake, we set a threshold of 5 for DOP so that it will stop averaging points above 5. During these times if was very difficult to plot trees at all so Roger and I set our schedules around the clear days when the DOP was low (as indicated by an online, daily DOP chart). The signal was also interrupted by cloud cover and even the trees themselves. The DOP tended to spike on 3 sides of a tree and be consistently low on the 4th side. So each day I had to place the Holux receiver on different sides of the trees. The 31 GPS satellites currently orbiting earth are spaced such that each satellite passes over the same point just a few minutes earlier each day. In general, this created a consistent low DOP for Roger and I during Monday afternoons.

When plotting our trees we used a reference guide that was put together in the mid 1990’s, and since then there have been many tree removals as well as growth which made it difficult to distinguish which tree was which. There were also new trees added since then that we started a new number series for. The old trees were between 1 and about 300 so our series started from 1000 and worked its way up. These trees are the light blue ones on the map in the center. The old trees (1-300) are marked by the yellow dots, and the apple orchard is the orange triangles to the south. The apple orchard also got its own number series starting at 1100.

Recommendations for the future

Roger and I only had one computer to work on and one set of GPS/GIS equipment. This problem resulted in working on the same thing all the time. The format of this internship resulted in a one person job being done by two people for the sake of both of them learning it. If we were able to have two sets of GIS/GPS equipment or figure out a different format for learning the software I feel it could be more efficient. Though, sometimes it was necessary for us both to be doing the same thing so that two brains were solving the same problem. This inefficiency has mostly led to just a less hands-on approach for me when Roger was on the computer troubleshooting and I was watching/guiding/suggesting. I also recommend on planning ahead so that the GPS mapping is done when the DOP is at its lowest point, this will keep operations more efficient. I feel as though it is important for the next intern to be very optimistic about what they can accomplish so that they do not get bogged down in the slowdowns which occur when working with new technology.

Key Contacts

Roger Trick- Whitman Mission historical site
Amy Molitor- Whitman College