hyDRaCAT Spectral Reflectance Library: Hyperspectral Field Spectroscopy and Field Spectro-Goniometry of Siberian and Alaskan Tundra

• Main Authors: Buchhorn, Marcel, Heim, Birgit, Schwieder, Marcel
• Format: Dataset
• Language: English
• Published: PANGAEA 2015
• Subjects: AWI_PerDyn; AWI Arctic Land Expedition; Comment of event; Date/Time of event; Elevation of event; Event label; FBG1; FBG2; FBG3; FBG4; File name; File size; Franklin Bluffs; Arctic North Slope; Alaska; United States of America; Happy Valley; HVG1; HVG2; Latitude of event; Location of event; Longitude of event; Permafrost Research (Periglacial Dynamics) @ AWI; Persistent Identifier; Remote Sensing of POlar Non-glaciated and Sensitive Environments; RESPONSE; Vaskiny Dachi; Yamal Peninsula; West Siberia; Russian Federation; VDG1; VDG2; Arctic; north slope; permafrost; Tundra; Siberia
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.855997; https://doi.org/10.1594/PANGAEA.855997

hyDRaCAT Spectral Reflectance Library for tundra provides the surface reflectance data and the bidirectional reflectance distribution function (BRDF) of important Arctic tundra vegetation communities at representative Siberian and Alaskan tundra sites. The aim of this dataset is the hyperspectral and spectro-directional reflectance characterization as basis for the extraction of vegetation parameters, and the normalization of BRDF effects in off-nadir and multi-temporal remote sensing data. The spectroscopic and field spectro-goniometric measurements were undertaken on the YAMAL2011 expedition of representative Siberian vegetation fields and on the North American Arctic Transect NAAT2012 expedition of Alaskan vegetation fields both belonging to the Greening-of-the-Arctic (GOA) program. For the field spectroscopy each 100 m2 vegetation study grid was divided into quadrats of 1 × 1 m. The averaged reflectance of all quadrats represents the spectral reflectance at the scale of the whole grid at the 10 × 10 m scale. For the surface radiometric measurements two GER1500 portable field spectroradiometers (Spectra Vista Corporation, Poughkeepsie, NY, USA) were used. The GER1500 measures radiance across the wavelength range of 350-1,050 nm, with sampling intervals of 1.5 nm and a radiance accuracy of 1.2 × 10**-1 W/cm**2/nm/sr. In order to increase the signal-to-noise ratio, 32 individual measurements were averaged per one target scan. To minimize variations in the target reflectance due to sun zenith angle changes, all measurements at one study location have been performed under similar sun zenith angles and during clear-sky conditions. The field spectrometer measurements were carried out with a GER1500 UV-VIS spectrometer The spectrogoniometer measurements were carried out with a self-designed spectro-goniometer: the Manual Transportable Instrument platform for ground-based Spectro-directional observations (ManTIS, patent publication number: DE 10 2011 117 713.A1). The ManTIS was equipped with the GER1500 spectrometer ...