Spectral Reflectance Measurements ARCSS grid Atqasuk, Alaska 2012

Spectral measurements were taken on a 30 plot subset within the Arctic System Science (ARCSS) grid in Atqasuk, Alaska during the summer of 2012. Spectral measurements were taken from the north eastern most corner of each plot. The subset is located from E2-E6 & J2-J6 with the 1 km^2 ARCSS grid. The instrumentation used was a Unispec dual channel (DC) spectrometer with fiber optics as sensors. A manfrotto tri-pod with an arm attachment was used to hold the fibers and sensors in place while taking the spectral measurements. The arm had 2 bubble levels to assist in keeping the sensors as level as possible. The calculated foot print cover is about 50-60 cm using a tri-pod height of 1.62 meters. The sensor angle for each scan is 20 degrees. Extra reference scans were taken on a 100 percent reflective white board surface. Some plots contain crosshairs that are used for point framing purposes and might have an effect on the reflectivity of each scan. Therefore, an extra scan was taken adjacent to each plot on the west side.

2012年夏季，科研团队在阿拉斯加州阿特卡斯克（Atqasuk）的北极系统科学（Arctic System Science, ARCSS）网格内的30个样方子集中开展了光谱测量。所有测量均在每个样方的最东北角进行。该子集位于1平方千米的ARCSS网格内的E2-E6与J2-J6区域。实验所用仪器为搭载光纤传感器的Unispec双通道（dual channel, DC）光谱仪。研究采用曼富图（Manfrotto）三脚架搭配臂架附件，用于在光谱测量过程中固定光纤与传感器；该臂架配备两个气泡水准仪，以协助尽可能保持传感器处于水平状态。当三脚架高度为1.62米时，测算得到的传感器视场覆盖范围约为50至60厘米，单次扫描的传感器角度为20°。此外，研究团队还在反射率为100%的白板表面完成了额外的参考扫描。部分样方带有用于点位框定的十字标线，这可能会对单次扫描的反射率造成影响，因此研究团队在每个样方的西侧邻近区域额外开展了一次扫描。