Weaver Steven A, Ucar Zennure, Bettinger Pete, Merry Krista
Warnell School of Forestry and Natural Resources, 180 E. Green Street, University of Georgia, Athens, Georgia, United States of America, 30602.
PLoS One. 2015 Apr 29;10(4):e0124696. doi: 10.1371/journal.pone.0124696. eCollection 2015.
The static horizontal position accuracy of a mapping-grade GNSS receiver was tested in two forest types over two seasons, and subsequently was tested in one forest type against open sky conditions in the winter season. The main objective was to determine whether the holding position during data collection would result in significantly different static horizontal position accuracy. Additionally, we wanted to determine whether the time of year (season), forest type, or environmental variables had an influence on accuracy. In general, the F4Devices Flint GNSS receiver was found to have mean static horizontal position accuracy levels within the ranges typically expected for this general type of receiver (3 to 5 m) when differential correction was not employed. When used under forest cover, in some cases the GNSS receiver provided a higher level of static horizontal position accuracy when held vertically, as opposed to held at an angle or horizontally (the more natural positions), perhaps due to the orientation of the antenna within the receiver, or in part due to multipath or the inability to use certain satellite signals. Therefore, due to the fact that numerous variables may affect static horizontal position accuracy, we only conclude that there is weak to moderate evidence that the results of holding position are significant. Statistical test results also suggest that the season of data collection had no significant effect on static horizontal position accuracy, and results suggest that atmospheric variables had weak correlation with horizontal position accuracy. Forest type was found to have a significant effect on static horizontal position accuracy in one aspect of one test, yet otherwise there was little evidence that forest type affected horizontal position accuracy. Since the holding position was found in some cases to be significant with regard to the static horizontal position accuracy of positions collected in forests, it may be beneficial to have an understanding of antenna positioning within the receiver to achieve the greatest accuracy during data collection.
在两个季节里，在两种森林类型中测试了测绘级全球导航卫星系统（GNSS）接收机的静态水平位置精度，随后在冬季，针对一种森林类型在开阔天空条件下进行了测试。主要目的是确定数据采集期间的持握位置是否会导致静态水平位置精度有显著差异。此外，我们想确定一年中的时间（季节）、森林类型或环境变量是否会对精度产生影响。总体而言，当不采用差分校正时，发现F4Devices Flint GNSS接收机的平均静态水平位置精度水平在这类普通接收机通常预期的范围内（3至5米）。在森林覆盖下使用时，在某些情况下，GNSS接收机垂直持握时提供的静态水平位置精度高于以一定角度持握或水平持握（更自然的位置）时，这可能是由于接收机内天线的方向，或部分由于多径效应或无法使用某些卫星信号。因此，由于众多变量可能影响静态水平位置精度，我们只能得出结论，持握位置的结果有显著影响的证据很弱到中等。统计测试结果还表明，数据采集季节对静态水平位置精度没有显著影响，结果表明大气变量与水平位置精度的相关性较弱。在一项测试的一个方面发现森林类型对静态水平位置精度有显著影响，但除此之外，几乎没有证据表明森林类型会影响水平位置精度。由于在某些情况下发现持握位置对于在森林中采集的位置的静态水平位置精度有显著影响，了解接收机内天线的定位可能有助于在数据采集期间实现最高精度。
