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Atqasuk, Alaska Vegetation Leaf Data
Alaska, USA, 2018

Data authors: Sergio Vargas Zesati (1), Craig E. Tweedie (1), Karl F. Huemmrich (2), Petya Campbell (2)

1. System Ecology Lab, University of Texas at El Paso
2. University of Maryland Baltimore County, NASA Goddard Space 	Flight Center

Funding from: NASA ABoVE (Grant # NNX17AC58A)

Version: 2018-05-18

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CONTENTS

1.       Data overview
2.       Use of data
3. 	 Temporal and spatial characteristics
4.       File information

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1. DATA OVERVIEW

This dataset represents full spectrum (i.e. 350 - 2500nm) leaf spectral reflectance data for species located in Atqasuk, Alaska. Scans were collected in a controlled lab setting using a HR-1024i spectrometer, leaf-clip and fibers. Samples were collected and scanned the same day during the 2017 summer growing season and acquired data were calibrated using a Spectralon white reference panel included in the leaf clip. ***Warning*** Some dates might be missing scans due to either bad data and/or as a result of data QC efforts. 

Data Uncertainty: 
No specific quality assessment information is provided.

Correspondence concerning these data should be directed to:
Dr. Sergio A. Vargas Zesati
University of Texas at El Paso
Systems Ecology Lab
500 W. University Ave. 
El Paso, Texas, 79968

email:  savargas@utep.edu
	ctweedie@utep.edu


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2. USE OF DATA

These data are made freely available to the public and the scientific community in the belief that their wide dissemination will lead to greater understanding and new scientific insights.

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3. TEMPORAL AND SPATIAL CHARACTERISTICS

Temporal range: 2017-06-17 to 2017-08-22
Temporal resolution / sampling frequency: 1 time during the field season

Geographic location / Transect boundaries:
Westernmost Longitude:  -157.406290
Easternmost Longitude:  -157.404686°
Northernmost Latitude:    70.453206°
Southernmost Latitude:    70.452962°

Site description:
Mobile Instrumented Sensor Platform (MISP) transects (2 x 50 meters) were established at various locations throughout the Arctic as a contribution to the US Arctic Observing Network (AON),(Healey, N.C., et al. 2014). Each 50 meter transect was divided into smaller 1 x 2 meter plots and marked with white wooden boards secured to the tundra with 12” metal stakes. The robotic sensor systems collect high spatial and temporal resolution environmental data across a multitude of vegetation functional types and spanning a moisture and latitudinal gradient across the Arctic.

Spatial resolution: spectral reflectance point samples for an approximate 1 meter squared area.

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4. FILE INFORMATION

Data file format: comma-separated text (.csv)

Data file description: The first row in each csv data file represents the wavelength (nm) and each row following thereafter is each plot or scan and are identified using the Unique_ID in column A, which is linkable with the metadata spreadsheet information (see below). The coordinates provided in the metadata spreadsheet were acquired using either a DGPS or handheld GPS.

Metadata file description: Each scan or data record is stored by row and is assigned a Unique_ID, which can be used to query a particular measurement as detailed as by day and/or time of day. As seen in the metadata sheet, the Unique_ID column is basically composed of the first 8 columns of metadata which include the “Location”, “Site_Name”, “Target_Name”, “Target_Scale_Level” (e.g. plot (PL), leaf (LF) etc.), “Measurement_Julian_Day”, “Measurement_Time_Of_Day”, “Measurement_Year”, and “Measurement_Type” (e.g. reflectance (REFL), radiance (RAD) etc.).

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