Development of the Educational Application of GPS for Supporting Chilren's Cognition of the Map.

本研究的目的在于厘清全球定位系统在教育领域应用时所存在的问题，并针对这些问题提出解决方案。特别是利用GPS系统辅助儿童对地图认知的问题。由于GPS系统是为军事用途而设计的，因此其精度受到限制。在我们的实验中，我们发现了几百米的误差。通常，汽车导航系统使用的是基于道路地图的误差校正算法。但在教育用途中，可能没有通常的路线图，如公园或小巷的情况。我们发现，大多数错误发生在系统无法捕捉卫星时。捕获的卫星数量越少，误差越大。因此，我们开发了通过计算移动速度和误差长度来校正误差的原始算法。我们发现使用该算法可以减少大部分的错误。目前，我们已经看到了利用该算法在GPS系统的教育应用中取得成功的前景。

The purpose of this research are to clarify problems using GPS system in educational field and make solutions to those problems. Especially problems in using GPS system for supporting children's congnition of the map.The result of the research is following. Because GPS system is designed for military use, There are restriction about the accuracy. We find some hundreds meters error in out experiment.Usually, Car navigation system is using the algorithm that correct errors by using roadway maps. But In educational use, there may be no usual roadmaps, like a situation of parks, or alley.We have found that most errors occurs when the system fail to catch satellites. More the numbers of caught satellite reduces, More errors occurs. So, we developed the original algorithm that corrects error by calculating moving speed and the length of error. We find most of errors are reduced by using this algorithm. Now, We have prospect of success in educational use of GPS system by using this algorithm.