ABoVE: Ground-based Reflectance Spectra of Vegetation at Multiple Sites Across Alaska

This dataset includes ground-based reflectance spectra collected using a Spectral Evolution PSR+ spectroradiometer during July and August of 2018 and 2019 as part of the NASA Arctic Boreal Vulnerability Experiment (ABoVE). Ground spectra provide high spectral resolution reference measurements for vegetation and surface targets that occur within or near UAV image footprints and across the broader ABoVE Domain in Alaska. Scans were collected using either a leaf clip or contact probe fiber optic, both equipped with an internal tungsten halogen illumination source that minimizes ambient light contamination and provides a stable illumination geometry. The data are provided in comma separated values (CSV) format.

There is one data file in this dataset in CSV format.

This dataset includes ground-based reflectance spectra collected using a Spectral Evolution PSR+ spectroradiometer during July and August of 2018 and 2019 as part of the NASA Arctic Boreal Vulnerability Experiment (ABoVE). Ground spectra provide high spectral resolution reference measurements for vegetation and surface targets that occur within or near UAV image footprints (provided in Nelson et al., 2026) and across the broader ABoVE Domain in Alaska. Scans were collected using either a leaf clip or contact probe fiber optic, both equipped with an internal tungsten halogen illumination source that minimizes ambient light contamination and provides a stable illumination geometry.

Project: Arctic-Boreal Vulnerability Experiment

The Arctic-Boreal Vulnerability Experiment (ABoVE) is a NASA Terrestrial Ecology Program field campaign being conducted in Alaska and western Canada, for 8 to 10 years, starting in 2015. Research for ABoVE links field-based, process-level studies with geospatial data products derived from airborne and satellite sensors, providing a foundation for improving the analysis, and modeling capabilities needed to understand and predict ecosystem responses to, and societal implications of, climate change in the Arctic and Boreal regions.

Related Dataset

Nelson, P.R. 2026. ABoVE: UAV VNIR Imaging Spectroscopy and Derived Plant Functional Types. ORNL DAAC, Oak Ridge, Tennessee, USA. https://doi.org/10.3334/ORNLDAAC/2503

• Imagery collected from a UAV over or near the same study area and same time frame. Ground spectra provided in the current dataset were used to support interpretation, classification, and validation of those UAV imagery-derived PFT products included in Nelson 2026.

Spatial Coverage: Multiple locations within the Alaskan Arctic and boreal regions of the NASA ABoVE Domain 

ABoVE Reference Locations
     Domain: Core ABoVE 

Spatial Resolution: point measurments

Temporal Coverage: 2018-07-01 to 2019-08-31

Temporal Resolution: once

Study Area: Latitude and longitude are given in decimal degrees.

Site	Westernmost Longitude	Easternmost Longitude	Northernmost Latitude	Southernmost Latitude
Alaska	-149.26215	-146.64314	65.03301	63.88326

Data File Information

Ground spectra are provided as a CSV spectral library file: Alaska_veg_ground_based_spectral_library.csv.
The file contains 1,334 individual scans representing 98 species and includes taxonomic fields (e.g., species and genus), plant functional group assignments, optional latitude/longitude coordinates, and reflectance values at 1 nm wavelength increments (350 to 2500 nm).

Table 1 contains the variables in the data file. Additional table summaries are provided for the following: the number of scans per area (Table 2), the number of PSR+ scans contributing to functional group 1 (Table 3), and a summary of the number of scans per species (Table 4). 

Table 1. Variables in ground_based_spectral_library.csv. Geographic coordinates (latitude/longitude) are available for 255 scans (~19.1%); scans without coordinates were typically collected from samples measured away from the collection point (e.g., at a central staging location) or without a GPS fix at the time of scanning. The missing data value is -9999

Variable	Units	Description
ScanID		ScanID-site_#
Area		Area where scans were made in Alaska
Code_name		Scan code name
Species_name		Species scanned
Genus		Genus of the scanned species
Functional_group0		Functional group of the species
Functional_group1		Functional group 1 of the species scanned
Functional_group2		Functional group 2 of the species scanned
Species_name_Freq	1	Frequency of the species
Functional_group1_Freq	1	Frequency of species in Functional group1
Functional_group2_Freq	1	Frequency of species in Functional group 2
Latitude	decimal degrees	Latitude of the study site
Longitude	decimal degrees	Longitude of the study site
Wavelength (2151 columns)	nm	Reflectance values at 1 nm wavelength increments (350 to 2500 nm)

Table 2. Number of scans per area. Note: “Big Trail” in the spectra library corresponds to the Big Trail Lake (Clayton Lake) location used for UAV imagery (Nelson et al., 2026). Study Area is the name recorded in this library.

Study Area	Number of scans
Murphy	341
Murphy Dome	213
Barrow	149
Yukon_Delta	125
Seward_Penn	116
Brooks_Range	104
Fairbanks area	69
12mile	62
Big Trail	61
Eagle Summit	51
Fairbanks Area Spinach Circle	18
BirchLake	10
Fairbanks Area Vault Road	9
Eight Mile	5
Wickersham	1

Table 3. Summary of the number of PSR+ scans contributing to each functional group.

Functional_group1	Number of scans
Lichen	417
ShrubDecid	297
Forb	158
Moss	122
Graminoid	107
ShrubEvergreen	105
Abiotic	94
TreeBroadleaf	17
TreeConifer	17

Table 4. Number of scans per species

Species_name	Number of scans
Betula nana	62
Dryas sp.	58
Alnus sp.	57
Pestasites frigidus	52
Quartz	50
Salix alaxensis	47
Eriophorum angustifolium	36
Rhizocarpon geographicum	32
Flavocetraria nivalis	29
Masonhalea richardsonii	28
Arctostaphyllos	27
Carex aquatilis	27
Polytrichum sp.	26
Cladonia mitis	24
Lupinus sp.	23
Nephroma arcticum	21
Melanelia sp.	21
Pedicularis racemosa	20
Cladonia rangiferina	20
Salix pulchra	20
Rosa acicularis	20
Asahinea chrysantha	19
Umbilicaria hyperborea	19
Cladonia gracilis	18
Picea mariana	17
Bare Soil	17
Salix glauca	16
Cladonia stellaris	16
Pilophorus acicularis	15
Cetraria islandica	14
Bare Rock	14
Hylocomium splendens	13
Betula neoalaskana	13
Vaccinium vitis-idea	13
Cladonia stygia	13
Aulacomnium palustre	12
Saxifraga punctata	12
Polytrichum juniperinum	12
Carex sp.	12
Rhytidum rugosum	12
Porpidia sp.	11
Ledum decumbens	11
Peltigera apthosa	10
Salix (wooly)	10
Alectoria ochroleuca	10
Dupontia fisheri	10
Salix richardsonii	9
Cassiope tetragona	9
Cladonia uncialis	9
Pleurozium schreberi	9
Petasites frigida	8
Cladonia amaurocraea	8
Loisleuria procumbens	8
Sphagnum sp.	8
Stereocaulon sp.	8
Dead Salix	8
Arctocetraria centrifuga	8
Heracleum lanatum	8
Cladonia steallaris	8
Aulacomnium turgidum	8
Petasites frigidus	7
Arctophila fulva	7
Toefeldia sp.	7
Dactylina arctica	7
Equisetum arvense	7
Peltigera scabrata	7
Eriophorum vaginatum	7
Salix ovalifolia	6
Empetrum nigrum	6
Rubus sp.	6
Vaccinium uliginosum	6
Cetraria laevigata	6
Ceratadon purpureus	5
Cladonia cornuta	5
Dicranum sp.	5
Pices (bark)	5
Trapelopsis granulosa	5
Arctagrostis latifolia	4
Umbilicaria arctica	4
Salix lanata	4
Tomenthypnum nitens	4
Iris sp.	4
Salix arbusculoides	4
Calamogrostis sp.	4
Populus balsamifera	4
Plagiomnium sp.	4
Peltigers leucophlebia	4
Peltigera malacea	4
Pedicularis sudetica	4
Parmeliopsis ambigua	4
Parmelia omphalodes	4
Equisetum sylvaticum	4
Racomitrium lanoiginosum	4
Salix phlebophylla	3
Rhizocarpon sp.	3
Cladonia sulphurina	3
Arenaria pseudofrigida	1
Hieracium sp.	1

The ground spectra included in this dataset were used to support interpretation, classification, and validation of UAV imagery-derived PFT products (Nelson 2026). These data also support fine-scale vegetation mapping, training and validation of airborne imaging spectroscopy products such as AVIRIS-NG, and ecological research within the NASA ABoVE Domain.

Not provided

The submitted ground spectral library contains 1,334 individual scans representing 98 species. Geographic coordinates (latitude / longitude) are available for 255 scans (~19.1%); scans without coordinates were typically collected from samples measured away from the collection point (e.g., at a central staging location) or without a GPS fix at the time of scanning. The spectra were collected at multiple Alaska field locations within the ABoVE Domain using a Spectral Evolution PSR+ spectroradiometer. Scans were collected using either a leaf clip or contact probe fiber optic, both equipped with an internal tungsten halogen illumination source that minimizes ambient light contamination and provides a stable illumination geometry.

Figure 2. PSR+ ground spectra locations (scans with GPS coordinates). This map only includes those 254 spectra samples with geographic coordinates in five areas: Fairbanks Area Vault Road (9 scans), Murphy Dome (213 scans), Fairbanks Area Spinach Circle (18 scans), BirchLake (10 scans), and Eight Mile (5 scans)

Nelson, P.R. 2026. ABoVE: UAV VNIR Imaging Spectroscopy and Derived Plant Functional Types. ORNL DAAC, Oak Ridge, Tennessee, USA. https://doi.org/10.3334/ORNLDAAC/2503