It is standard practice in satellite remote sensing of earth objects to field check imagery by locating specific places or objects using GPS (Global Positioning Systems). After teaching remote sensing courses for three years, and introducing GPS in them, it became clear that many of my students did not learn GPS technology well enough to successfully ground check satellite data and therefore a more effective way of teaching GPS was needed. Inspired by the common hobby of geocaching, I created a new fun and engaging activity for my university courses and teacher courses: the GPS treasure hunt. Two variations of the hunt have been undertaken with 297 teachers and students over four years. The results and impact of this activity have been overwhelmingly positive. Specific GPS-oriented questionnaires administered in several of the courses indicates that 34% of respondents had never used GPS units until completing the activity. After completing the hunt, 89% proclaimed that they felt comfortable using GPS units and would be able to find the location of any given object after the activity. Since introducing this activity, no student has required additional assistance in subsequent exercises that require the use of GPS units.
The use of Global Positioning System (GPS) receivers provides a highly effective toolfor understanding spatial relationships in Earth Science applications. Understanding GPS, and how to use it, is crucial for ground checking satellite data and for establishing and relocating sites of data collection. Hence I teach GPS technology in all my satellite remote sensing, geoscience, and K-12 teacher professional development courses.
In the past, before I introduced GPS treasure hunts in my courses, I typically provided one class period of GPS instruction. This included how to operate the units and how to determine the user's location on the surface of the Earth using GPS. However, I found that typically more than half of any given class needed continual refresher lessons throughout the semester. As a remote sensing educator, this was frustrating as the important task at hand was to ground check satellite imagery, yet some students could not overcome the hurdle of understanding GPS. Although Herrstrom (2000) states that GPS is a non-threatening technology, I realized that like other technical devices, some students were, and are, still intimidated by GPS units even though they are relatively simple to operate. It therefore became apparent that an effective method of teaching GPS was essential to allow students to learn the concepts of, and be comfortable with, GPS quickly. While many educators have developed lesson plans for incorporating GPS into courses (e.g. Herrstrom, 2000, Frizado and Onasch, 2001), few have dealt with effective teaching strategies of GPS itself. Weiss and Walters (2004) successfully incorporated GPS into a geology walking tour of campus. Since students had to find geological "specimens" across campus, a good sense of spatial relationships were achieved.
This paper presents an activity that has demonstrated an immediate impact on student learning of GPS technology. The activity is based on the common hobby of geocaching in the Cleveland area of Ohio and it is now commonly referred to in my courses as the "GPS treasure hunt". This hunt has been completed with 15 classes and has introduced 297 university students and K-12 teachers to GPS. Of these 15 classes, five were teacher professional development courses, five were geospatial courses, and five were introductory or intermediate geography courses (Table 1).
THE IMPORTANCE OF GPS IN REMOTE SENSING APPLICATIONS
Remote sensing is the retrieval of information about objects without being in contact with those objects. In earth science applications, remote sensing is usually performed through satellite imagery and air photo analysis. Satellite dataset access in Ohio is excellent because of the efforts of OhioView, a consortium of 12 state universities whose mission is to outreach to schools and businesses and promote the use of satellite imagery for little or no cost. …