******************************************************************** * * * BU/UCL/UWS Jornada Albedo Data * * * * README for data files * * * * Andrew Hyman 12th August 1998 * * * ******************************************************************** -------------------------------- 1. Introduction and Team Members -------------------------------- This README file details data collected by Boston University in collaboration with University College London and University Wales, Swansea during the PROVE campaign at Jornada, NM May 20-30 1997 as part of a coordinated MODLAND validation prototyping exercise. Funding was provided by NASA grant NAS5-31369 (PI: Prof Alan Strahler). Full background information on data processing and results of our analyses are available in the Master's Thesis by Andrew Hyman (1998) which is included in postscript format with the data and our work will subsequently be published in Remote Sensing of Environment in 1999 / 2000 (see below for further details). Boston University ----------------- Lead Investigator: Andrew Hyman e-mail: ahh24@cam.ac.uk (from 1 October 1998 with Department of Geography, University of Cambridge, UK) Wolfgang Lucht e-mail: wlucht@crsa.bu.edu Alan Strahler e-mail: alan@bu.edu In collaboration with: University College London ------------------------- Jan-Peter Muller University of Wales, Swansea ---------------------------- Mike Barnsley Paul Hobson Please direct any questions you may have regarding the data to either: Dr Wolfgang Lucht, Center for Remote Sensing, Boston University, 725 Commonwealth Avenue, Boston, MA 02215. Tel: +1 (617) 353 8033 Fax: +1 (617) 353 3200 e-mail: wlucht@crsa.bu.edu or: Andrew Hyman, Department of Geography, University of Cambridge, Downing Place, Cambridge CB2 3EN, United Kingdom. e-mail: ahh24@cam.ac.uk ---------------------------- 2. Description of data files ---------------------------- a) Total shortwave and NIR broadband albedo data Broadband albedo data was collected using Kipp and Zonen CM14 albedometers. List of data files: a) The following files contain albedo values collected along 5 transects which are identified by date and name in the filename. The albedo values in these files are averages of 5 (or occassionally more) measurements taken at each point on the transects. The file format is: Site local_time GMT SW_albedo NIR_albedo solar_azimuth solar_zenith latitude longitude height photoid Where: Site is site number for the north, south, east and west transects and 1 references the site closet to the tower and 11 the site farthest from the tower. For the grassland transects, site 1 is located at the end by the road / fence. SW_albedo is the total broadband albedo 305-2800nm NIR_albedo is the NIR broadband albedo 695-2800nm Latitude and longitude, provided in decimal degrees are from differentially corrected GPS measurements with the WGS84 datum. Data was collected using a Trimble GeoExplorer II. 120 samples were taken at each location point with a 5 second sampling rate ensuring a minimum of 4 satellites were in view. Differential correction was performed using coincident measurements taken using data from the permanent Trimble GPS installation at New Mexico State University. Height is in metres above MSL photoid is an idenitifier for associated Hemispherical photographs and classified images Files: ------ In "albedo" directory 22ndMay1997_north_sza_corrected.dat 23rdMay1997_east_sza_mois_corrected.dat 23rdMay1997_north_sza_corrected.dat 23rdMay1997_south_sza_mois_corrected.dat 25thMay1997_longeast_sza_corrected.dat 25thMay1997_middle_longeast_sza_corrected.dat 26thMay1997_north_sza_corrected.dat 26thMay1997_west_sza_corrected.dat 27thMay1997_grassland1_sza_corrected.dat 27thMay1997_grassland2_sza_corrected.dat 27thMay1997_grassland3_sza_corrected.dat Notes: i) sza files provide values with corrections for solar zenith angle effects for the north, west, longeast and grassland transects ii) sza_mois files provides values for the south and east transect measurements corrected for both solar zenith angle and soil moisture effects iii) grassland1, grassland2 and grassland3 refer to three transects measured at different times on the 27th May iv) Decimalised time is calculated using: (($2!=0)&&($1!="#")){ time=$2; hours=int(time/10000); time-=(hours*10000); minutes=int(time/100); seconds=time-(minutes*100); print (hours*3600 + minutes*60 + seconds) } b) Hemispherical photography was acquired for all sites for which albedo was measured. File names correspond to photoid field in albedo data files. These are located in the "hemi_photo directory" Header information for hemispherical photography (*photo.bin) files is: Number of lines: 1024 Number of samples: 1536 Number of bands: 3 (BIP - Band Interleaved by Pixel) Bytes: 1 Byteorder: 3210 (as reported by IPW) Header information for classified image (*classified.bin) files is: Number of lines: 1024 Number of samples: 1536 Number of bands: 1 Bytes: 1 Byteorder: 3210 (as reported by IPW) The classified images contain five values: Digital Number Class 0 Unclassified 50 Soil 100 Grey / dormant vegetation 150 Dead / woody vegetation 200 Live vegetation c) Postscript files of the MA Thesis which provides a full report on the study are: In the "thesis" directory: File: Contents: jornada_albedo_prelim.ps Preliminary pages jornada_albedo_main.ps Main text jornada_albedo_sec1_figs.ps Section 1 figures jornada_albedo_sec2_figs.ps Section 2 figures jornada_albedo_sec3_figs.ps Section 3 figures jornada_albedo_sec4_figs.ps Section 4 figures jornada_albedo_sec5_figs.ps Section 5 figures jornada_albedo_sec6_figs.ps Section 6 figures jornada_albedo_references.ps References These are formatted for US Letter Size paper. ------------------------------------------------------ 3. Requested Acknowledgement / References for data use ------------------------------------------------------ Please note that use of this data should include the following reference: Hyman, A.H. 1998: Characterising the spatial variability of albedo in a semi-desert environment for the validation of satellite data. Master's Thesis, Boston University, unpublished. Citations should subsequently make reference to journal articles to be published in a special issue of Remote Sensing of Environment on Jornada in 1999 or early 2000. Please check with Andrew Hyman (ahh24@cam.ac.uk) or Wolfgang Lucht (wlucht@crsa.bu.edu) for latest status.