------------------------------------------------------------------
Utqiagvik (formerly Barrow), Alaska ITEX Vegetation Reflectance Data Alaska, USA, 2018

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

1. Systems 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: 2018-07-25
Prepared by: 

--------------------------------------------------------------------
CONTENTS

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

--------------------------------------------------------------------
1. DATA OVERVIEW

This dataset represents full-spectrum (i.e. 350-2500nm) plot-level spectral reflectance data for vegetation plots within the dry and wet ITEX sites near Utqiagvik, Alaska. Scans were collected using a Spectra Vista Corporation (SVC) HR-1024i spectrometer, standard pistol grip and fibers. Data were calibrated using a Spectralon white reference panel for changing light conditions during field sampling. ***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


--------------------------------------------------------------------
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.

--------------------------------------------------------------------
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: -156.606868°
Easternmost Longitude: -156.595131°
Northernmost Latitude: 71.318749° 
Southernmost Latitude: 71.309110°

Site description:
The International Tundra Experiment (ITEX) site in Utqiagvik is composed of historical plant phenology observations that represent dominant species across the northern Arctic. 


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

--------------------------------------------------------------------
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.) and are highlighted in blue. Header names for each column are color coded based on the type of metadata each column represents (e.g. yellow- Project level information, light purple- Site level information, green- Measurement level information and blue- fields that make up the Unique_ID.) 

--------------------------------------------------------------------