BOREAS RSS-20 POLDER Radiance Images from the NASA C-130 

Summary

These data are a subset of images collected by the POLDER instrument over tower 
sites in the BOREAS study areas during the IFCs in 1994.  The POLDER images 
presented here from the NASA/Ames C-130 aircraft are made available for 
illustration purposes only.  The data are stored in binary image-format files.

Note that some of the data files on the BOREAS CD-ROMs have been compressed 
using the Gzip program.  See Section 8.2 for details.

Table of Contents

   *  1 Data Set Overview
   *  2 Investigator(s)
   *  3 Theory of Measurements
   *  4 Equipment
   *  5 Data Acquisition Methods
   *  6 Observations
   *  7 Data Description
   *  8 Data Organization
   *  9 Data Manipulations
   *  10 Errors
   *  11 Notes
   *  12 Application of the Data Set
   *  13 Future Modifications and Plans
   *  14 Software
   *  15 Data Access
   *  16 Output Products and Availability
   *  17 References
   *  18 Glossary of Terms
   *  19 List of Acronyms
   *  20 Document Information

1. Data Set Overview

1.1 Data Set Identification

BOREAS RSS-20 POLDER Radiance Images from the NASA C-130
1.2 Data Set Introduction
POLarization and Directionality of Earth Reflectances (POLDER) is an instrument 
that measures Bidirectional Reflectance Distribution Function (BRDF) and 
Bidirectional Polarization Distribution Function (BPDF) of terrestrial surfaces 
in several visible and near-infrared spectral bands.  The instrument scanned 
several surface types (pine, spruce, fen, and others) in the BOReal Ecosystem-
Atmosphere Study (BOREAS) study areas during the various Intensive Field 
Campaigns (IFCs) in 1994.  Single-point BRDF measurements were acquired either 
from the National Aeronautics and Space Administration (NASA) C-130 aircraft or 
from a NASA helicopter. POLDER images acquired from the C-130 are made available 
for illustration purposes.

1.3 Objective/Purpose

The objective of this investigation was to characterize the bidirectional 
reflectance properties of different cover types in boreal forests over several 
seasons (IFC-1, -2, and 3). This characterization can then be used to retrieve 
biophysical parameters such as Leaf Area Index (LAI), chlorophyll content, and 
structural canopy parameters, either through the use of semiempirical relations 
between reflectances and biophysical parameters or through the inversion of a 
BRDF radiative transfer model. The overall goal is to establish methodologies of 
monitoring the ecological state of the boreal forest using remote sensing 
techniques.

1.4 Summary of Parameters

This data set contains POLDER images acquired from the C-130 at approximately 
5500 m over the various tower sites.

1.5 Discussion

Warning: The C-130 POLDER images are given as a qualitative information only.  
Although the measurements have been calibrated, no geometric correction has been 
applied.

1.6 Related Data Sets

BOREAS RSS-01 PARABOLA Surface Reflectance and Transmittance Data
BOREAS RSS-02 Level-1b ASAS Imagery: At-sensor Radiance in BSQ Format
BOREAS RSS-03 Helicopter-Mounted MMR Reflectance Data
BOREAS RSS-11 Airborne Tracking Sun Photometer Data
BOREAS RSS-20 POLDER BRDF Measurements of Tower Flux Sites

2. Investigator(s)

2.1 Investigator(s) Name and Title

Dr. Marc Leroy, Dr. Franois-Marie Bron, Patrice Bicheron, Olivier Hautecoeur

2.2 Title of Investigation

Airborne Remote Sensing Measurements with the POLDER Instrument

2.3 Contact Information

Contact 1
-------------
Dr. Marc Leroy
Centre d'Etudes Spatiales de la Biosphre (CESBIO) 
Toulouse Cedex, France
+33 5 61 55 85 14
+33 5 61 55 85 00 (fax)
Marc.Leroy@cesbio.cnes.fr

Contact 2
----------------
Dr. Franois-Marie Bron 
Laboratoire de Modlisation du climat et de l'Environnement 
Gif sur Yvette, France
+33 1 69 08 94 55
+33 1 69 08 77 16 (fax)
fmbreon@cea.fr 

Contact 3
--------------
Jaime Nickeson 
Raytheon ITSS
NASA/GSFC
Greenbelt, MD 
(301) 286-3373
(301) 286-0239 (fax)
Jaime.Nickeson@gsfc.nasa.gov

3. Theory of Measurements

POLDER is an optical sensor designed to observe the surface reflectance in 
visible and near-infrared bands.  Its main characteristic is that it can observe 
an area from various directions.  POLDER has a wide field-of-view (FOV) lens 
with  51 along-track and  43 cross-track viewing, and a charge-coupled 
device (CCD) array detector to collect images.

From the NASA Ames Research Center (ARC) C-130 aircraft at an altitude of 
approximately 5500 m, the surface cannot be considered homogeneous. POLDER's 
capacity to observe an area from various view angles is used to constitute 
complete BRDF with the successive images acquired along different flight axes 
over the experimental site.

4. Equipment

4.1 Sensor/Instrument Description

4.1.1 Collection Environment

It is mandatory to operate POLDER only under totally clear sky conditions, so 
that the distribution of irradiance does not change from one measurement to the 
next, and so that calculation of reflectances in absolute units from radiances 
is possible.  

4.1.2 Source/Platform

During IFC-1 and IFC-2, the POLDER instrument was installed alternatively on the 
C-130 aircraft, or on the helicopter.  During IFC-3, the instrument flew only on 
the helicopter.  POLDER C-130 data were acquired only in the Southern Study Area 
(SSA) (Prince Albert). 

4.1.3 Source/Platform Mission Objectives

The POLDER mission objective was to collect multiangle and multispectral 
bidirectional reflectance data over flux tower and auxiliary sites to study the 
boreal forest canopy. 

4.1.4 Key Variables

POLDER measures multispectral radiance in the visible and near-infrared domain 
as a function of Sun-view geometry.

4.1.5 Principles of Operation

The POLDER optical system consists of a telecentric lens, a filter wheel, and a 
CCD array as a detector. The light is almost vertically incident on the filter 
wheel after passing the telecentric lens. The CCD array (288 x 384 elements) can 
collect 2-D images. The filter wheel contains 10 slots for spectral filters and 
polarizers. The first channel is reserved for dark current measurement, while 
the others allow measurements in five spectral bands (443, 550, 670, 864, and 
910 nm). Two spectral bands (443 and 864 nm) are associated with three polarized 
filters oriented by steps of 60. A 10-channel image, corresponding to the 10 
positions of the filter wheel, is collected within 3 seconds.  Each image 
acquisition is repeated every 10 seconds.

The POLDER optical system was installed on the C-130 aircraft in the forward 
bay.  Aircraft position and attitude parameters provided by the onboard 
navigation system were recorded by POLDER electronics subsystem for data 
postprocessing.  Typical flight altitude was 5500 m.  Flight lines were designed 
on each site to collect images in the principal, perpendicular, and 45 solar 
planes.

4.1.6 Sensor/Instrument Measurement Geometry

The long axis of the CCD array was set parallel to the aircraft's longitudinal 
axis. An inclinometer was used to record the initial bias between the optical 
axis and true nadir.

4.1.7 Manufacturer of Sensor/Instrument

The instrument was designed and manufactured by Laboratoire d'Optique 
Atmosphrique (LOA), USTL, 59655 Villeneuve dAscq Cedex, France.

4.2 Calibration

Radiometric calibration data were acquired at LOA by J.-Y. Balois before and 
after the BOREAS experiment (11-May-1994 and 24-Oct-1994) using a calibrated 
integration sphere. The whole exit port of the integration sphere is used to 
derive the equalization coefficients   (see definition in Section 9.2.1). For 
absolute calibration, the exit port is reduced by a diaphragm to illuminate only 
a small circular area in the center of the CCD array. Readings of 15 x 15 pixel 
window are corrected for dark current and averaged to obtain the absolute 
calibration coefficients   (see Section 9.2.1).

Other calibration experiments were made during the BOREAS experiment using a 30-
inch (0.76 m) diameter portable hemisphere that is owned and operated by NASA 
GSFC. It was made available to the Remote Sensing Science (RSS)-20 team by Brian 
Markham and John Schaffer from NASA GSFC. The POLDER sensor was calibrated at 
the airport when POLDER was installed in the C-130 aircraft on (27-May-1994 and 
21-Jul-1994).

There is a good agreement between the LOA calibration and the first insitu 
calibration results. The second in-situ calibration shows discrepancies greater 
than 10% for all channels. The reasons for such discrepancies are still unknown.

4.2.1 Specifications

The general specifications of calibration accuracy were 5% absolute accuracy, 3% 
interband relative calibration accuracy, and 2% multitemporal relative 
calibration accuracy.

4.2.1.1 Tolerance

A general rise of the sensitivity was noted between the two calibration 
experiments made at LOA: 8% in the blue,  3.5% in the green and in the red, 5.5% 
for the 864-nm channel, and 5% for the 910-nm channel. For subsequent 
processing, mean coefficients obtained at LOA are used.

4.2.2 Frequency of Calibration

The instrument is generally calibrated once before an experimental campaign and 
once after the campaign.

4.2.3 Other Calibration Information

Having the spectral radiance at the outport of the sphere or the hemisphere, 
knowing the sensitivity of the various filters and the spectral value of the 
solar exoatmospheric irradiance, the normalized radiance is computed using:
[Note: Equations created in MS Word do not appear in ASCII text format.         
Please refer to the MS Word formatted guide document.]
 

L : spectral radiance (Wm-2sr-1m-1) as a function of wavelength (?i)
S : spectral sensitivity as a function of wavelength
E : spectral exoatmospheric solar irradiance (Wm-2m-1) as a function of 
    wavelength
The normalized radiance is used (see Section 9.2.1) to derive the absolute 
calibration coefficient  .

5. Data Acquisition Methods

For the C-130 data, the onboard navigation system gives information on the 
viewing geometry of each pixel.  Therefore, the location and attitude data yield 
an approximate position of a given surface target in all POLDER images. There is 
a time lag of 10 seconds between each image acquisition sequence.  For a typical 
C-130 flight altitude and speed, an angular resolution of approximately 10 
degrees is obtained.

6. Observations

6.1 Data Notes

None.

6.2 Field Notes

None.

7. Data Description

7.1 Spatial Characteristics

7.1.1 Spatial Coverage

The POLDER images were acquired over various tower site locations.  The North 
American Datum of 1983 (NAD83) coordinates are:

               West     North      UTM        UTM     UTM 
Site        Longitude  Latitude  Easting   Northing   Zone
-----       ---------  --------  -------   --------   ----
SSA Fen     104.61797  53.80206  525190.7  5961344.0   13
SSA OA      106.19779  53.62890  420821.8  5942678.0   13
SSA OBS     105.11779  53.98718  492306.1  5981879.0   13
SSA OJP     104.69203  53.91634  520257.0  5974035.0   13
SSA YJP     104.64527  53.87581  523350.7  5969540.0   13

7.1.2 Spatial Coverage Map

Not available.

7.1.3 Spatial Resolution

The pixel size is approximately 35 meters when POLDER is on the C-130. 

7.1.4 Projection

Each image is supplied in its original geometry with no geometric rectification 
or registration performed.  Users will need to at least rotate the images for a 
coarse registration.  The images are nearly centered on the tower sites. 

7.1.5 Grid Description

Not applicable.

7.2 Temporal Characteristics

7.2.1 Temporal Coverage

POLDER image data exist only for C-130 acquisitions taken from 26-May-1994 to 
24-July-1994.  Most experiments took place in the morning, except the following: 
21-July: OJP (around noon), YJP, Fen.. 

7.2.2 Temporal Coverage Map

Images from the C-130 exist for the following dates:

Site            IFC-1         IFC-2  
----         -----------   ------------  
Fen          07/24
OA           05/26,05/31
OBS          05/31,06/01   07/21
OJP          05/31,06/01   07/21, 07/24
YJP          06/01         07/21

7.2.3 Temporal Resolution

Most sites were visited more than once in 1994.

7.3 Data Characteristics

7.3.1 Parameter/Variable

Raw radiometric POLDER image data.

7.3.2 Variable Description/Definition

They are essentially normalized radiances.

7.3.3 Unit of Measurement

Unitless digital numbers.

7.3.4 Data Source

POLDER instrument mounted on the NASA C-130 Aircraft.

7.3.5 Data Range

None given.

7.4 Sample Data Record

Not applicable to image data.

8. Data Organization

8.1 Data Granularity

The smallest unit of data tracked by BORIS is a given image file.

8.2 Data Format(s)

8.2.1 Uncompressed Data Files
The image parameter is  , a digital number proportional to the observed 
normalized radiance for the channels without polarizers (see Section 9.2).  The 
image data are stored in a Band Sequential (BSQ) format (9 bands, 288 lines by 
384 pixels, 16 bits per pixel). 

	                  Bytes Per	Size
Description/Name    Format       Pixel    Npixels   Nlines	Nbands	(Bytes)
SSA-FEN_940724     Raw Binary      2	  384	     288	9	1990656
SSA-OA_940526      Raw Binary      2	  384	     288	9	1990656
SSA-OA_940531      Raw Binary      2	  384	     288	9	1990656
SSA-OBS_940531     Raw Binary      2	  384	     288	9	1990656
SSA-OBS_940601     Raw Binary      2	  384	     288	9	1990656
SSA-OBS_940721     Raw Binary      2	  384	     288	9	1990656
SSA-OJP_940531     Raw Binary      2	  384	     288	9	1990656
SSA-OJP_940601     Raw Binary      2	  384	     288	9	1990656
SSA-OJP_940721     Raw Binary      2	  384	     288	9	1990656
SSA-OJP_940724     Raw Binary      2	  384	     288	9	1990656
SSA-YJP_940601     Raw Binary      2	  384	     288	9	1990656
SSA-YJP_940721     Raw Binary      2	  384	     288	9	1990656

The table of the attitude parameters for these images follows:

                              Mean attitude parameters           Sun position
Site   Date     Hour      roll    pitch   heading   altitude   zenith   azimuth
----   ----     ----     ----    -----   -------   --------   ------   -------
FEN   940724  15:49:07    0.7     3.0      191.0    5645.2     49.3     114.3
OA    940526  16:47:03   -0.1     1.8       82.4    5482.44    41.8     127.7
OA    940531  15:31:45    0.4     2.6      263.2    5457.75    51.0     107.0
OBS   940531  17:19:52   -0.3     1.6      209.8    5489.75    37.3     139.5
OBS   940601  14:49:48    0.0     2.5      349.1    5552.54    53.4      98.6
OBS   940721  17:39:30   -0.4     1.1       16.8    5493.41    36.8     147.3
OJP   940531  16:27:49   -0.3     1.9      329.0    5461.41    42.9     123.4
OJP   940601  15:44:48   -0.2     2.3       68.0    5601.0     48.4     111.7
OJP   940721  18:27:14   -0.2     2.2      198.9    5558.03    33.9     166.7
OJP   940724  16:48:45   -1.6     1.4      229.0    5595.21    42.0     131.0
YJP   940601  15:53:55    0.1     1.4      194.0    5630.57    47.1     114.1
YJP   940721  19:25:35    0.1     2.3      331.2    5567.78    33.7     191.4

8.2.2 Compressed CD-ROM Files

On the BOREAS CD-ROMs, each of the 12 image files been compressed with the Gzip 
(GNU zip) compression program (file_name.gz).  These data have been compressed 
using gzip version 1.2.4 and the high compression (-9) option (Copyright (C) 
1992-1993 Jean-loup Gailly).  Gzip uses the Lempel-Ziv algorithm (Welch, 1994) 
also used in the zip and PKZIP programs.  The compressed files may be 
uncompressed using gzip (with the -d option) or gunzip.  Gzip is available from 
many WWW sites (for example, the ftp site prep.ai.mit.edu/pub/gnu/gzip-*.*) for 
a variety of operating systems in both executable and source code form.  
Versions of the decompression software for various systems are included on the 
CD-ROMs.

9. Data Manipulations

9.1 Formulae

See Section 9.2.

9.1.1 Derivation Techniques and Algorithms

See Section 9.2.

9.2 Data Processing Sequence

9.2.1 Processing Steps

9.2.1.1 Level 1 Images

The raw radiometric data are digital numbers noted  , where i, j are indices 
of pixel location on the CCD matrix, k is the wavelength, and a is the polarizer 
number for spectral bands comprising three polarizers. For the other spectral 
bands, a is meaningless.  The processing from level 0 to level 1 data consists 
of the transformation of raw data into data proportional to normalized radiances 
 , according to the equation:

[Note: Equations created in MS Word do not appear in ASCII text format.         
Please refer to the MS Word formatted guide document.]

 
with
	t0	reference exposure time, used in calibration : 100 ms
	t	exposure time during operation
	 	average of line j of dark current
	 	calibration coefficient
	 	relative sensitivity (high and low frequency) of instrumental 
(optics + CCD) transmission. It is normalized such that the local 
average of    at the matrix center equals 1.
	 	sensitivity of absolute calibration to CCD temperature
	 	CCD temperature during calibration
	T	CCD temperature in operation
	 	is a digital number proportional to the observed normalized radiance 
(for the channels without polarizers),  i.e., 
 
with
	 	observed radiance (Wm-2sr-1m-1) for pixel i, j in band k
	 	exoatmospheric solar irradiance in band k (Wm-2m-1).

For polarized bands, the aircraft displacement between successive channel 
acquisition must be taken into account to obtain a normalized spectral radiance 
from the three polarized channels
 
where (x,y) are surface coordinates that refer to CCD pixels coordinates (i,j) 
in each of the polarized channels viewing the same ground point (x,y). 
The level 1 images provide data that for each band are equal to the right-hand 
side of the two previous equations.  They are essentially normalized radiances.

The following table summarizes the POLDER C-130 data acquisitions and sun and 
atmospheric conditions:

                         Sun zenith angle      Aerosol optical thickness
Site          Date           degrees        at 550 nm (total/below aircraft)
----          ----       ----------------    -------------------------------
Fen          24-Jul        44.4 - 49.3                0.080/0.020
             03-May        38.4 - 42.8                0.130/0.055
OJP          01-Jun        48.4 - 51.4                0.095/0.050
             21-Jul        33.8 - 35.0                0.120/0.095
             24-Jul        40.5 - 43.3                0.095/0.020
             26-May        39.4 - 41.8                0.070/0.025
             01-Jun        44.0 - 47.0                0.095/0.050
YJP          21-Jul        35.5 - 37.2                0.115/0.090
             31-May        35.5 - 37.4                0.135/0.070
OBS          01-Jun        53.5 - 56.4                0.060/0.030
             21-Jul        33.4 - 33.7                0.115/0.090

9.2.2 Processing Changes

None.

9.3 Calculations

9.3.1 Special Corrections/Adjustments

Not applicable.

9.3.2 Calculated Variables

Radiance, and reflectance were calculated.

9.4 Graphs and Plots

None.

10. Errors

10.1 Sources of Error

For images and BRDF data, there is some uncertainty in the absolute calibration 
coefficient, as illustrated by the calibration tables shown above.  For the BRDF 
data, an additional source of error results from image registration.  In the 
processing, it is assumed that the position of the site is the same for all 
images of the sequence, which can induce an error in the location of less than 1 
pixel.  These errors are lessened with the spatial averaging procedure.  The 
smoothing aspect of the BRDF data tends to show that the misregistration errors 
are not critical.

10.2 Quality Assessment

10.2.1 Data Validation by Source

The POLDER data have been tested against the 4-scale BRDF reflectance model 
(Leblanc et al., 1997) as well as against the PARABOLA data and the DART 3-D 
BRDF model (Gastellu-Etchegorry et al., 1997).

10.2.2 Confidence Level/Accuracy Judgment

The uncertainty associated with POLDER spectral reflectances values, taking into 
account only error in the absolute calibration coefficient, is approximately 
less than 0.005 for the visible channels and 0.01 for the near-infrared channel.  
The confidence level in these measurements is good because of their 
reproducibility for different axes during the same flight. 

10.2.3 Measurement Error for Parameters

Not available.

10.2.4 Additional Quality Assessments

The directional reflectances obtained with POLDER data corrected from 
atmospheric effects for the flux tower or auxiliary sites can be compared to 
similar data made by other instruments.

10.2.5 Data Verification by Data Center

BORIS staff has looked at some of the POLDER imagery from the C-130.  It appears 
that there are some registration problems between bands in some of the imagery.

11. Notes

11.1 Limitations of the Data

None.

11.2 Known Problems with the Data

Based on a visual review of the images by BORIS staff, it appears that there are 
some registration problems between bands in the imagery.

11.3 Usage Guidance

Not applicable.

11.4 Other Relevant Information

None.

12. Application of the Data Set

Data set used for BRDF model inversion and BRDF direct models cross-check.

13. Future Modifications and Plans

None.

14. Software

14.1 Software Description

None given.

14.2 Software Access

Raw data and processing software might be available upon request.  See Section 
2.3.

15. Data Access

15.1 Contact Information

For BOREAS data and documentation please contact: 

ORNL DAAC User Services
Oak Ridge National Laboratory
Oak Ridge, TN
Phone:  (423) 241-3952
Fax:    (423) 574-4665
E-mail:  ornldaac@ornl.gov or ornl@eos.nasa.gov

15.2 Data Center Identification

Earth Observing System Data and Information System (EOSDIS) 
Oak Ridge National Laboratory (ORNL) 
Distributed Active Archive Center (DAAC) for Biogeochemical Dynamics
http://www-eosdis.ornl.gov/

15.3 Procedures for Obtaining Data

Users may obtain data directly through the ORNL DAAC online search and order 
system [http://www-eosdis.ornl.gov/] and the anonymous FTP site [ftp://www-
eosdis.ornl.gov/data/] or by contacting User Services by electronic mail, 
telephone, or fax. 

15.4 Data Center Status/Plans

The ORNL DAAC is the primary source for BOREAS field measurement, image, GIS, 
and hardcopy data products. The BOREAS CD-ROM and data referenced or listed in 
inventories on the CD-ROM are available from the ORNL DAAC. 

16. Output Products and Availability

16.1 Tape Products

The image data are stored on 8 mm media as BSQ raw images (9 bands, 288 lines by 
384 pixels, 16 bits per pixel).

16.2 Film Products

None.

16.3 Other Products

None.

17. References

17.1 Platform/Sensor/Instrument/Data Processing Documentation

Welch, T.A. 1984. A Technique for High Performance Data Compression. IEEE 
Computer, Vol. 17, No. 6, pp. 8-19.

17.2 Journal Articles and Study Reports

Bron, F.M., V. Vanderbilt, M. Leroy, P. Bicheron, C.L. Walthall, and J.E. 
Kalshoven. 1997. Evidence of hot spot directional signature from airborne POLDER 
measurements. IEEE Transactions on Geoscience and Remote Sensing, Vol. 35, pp. 
479-484. 
Bicheron, P., M. Leroy, O. Hautecoeur, and F.M. Bron. 1997.  Enhanced 
discrimination of boreal forest covers from airborne directional POLDER data. 
Journal of Geophysical Research, 102(D24):  29,517-29,528.
Deschamps, P.Y., F.M. Bron, M. Leroy, A. Podaire, A. Bricaud, J.C. Buriez, G. 
Sze. 1994. The POLDER mission: Instrument characteristics and scientific 
objectives. IEEE Transactions on Geoscience and Remote Sensing, 32, pp. 598-615.
Gastellu-Etchegorry J.P., P. Guillevic, F. Zagolski, V. Demarez, V. Trichon, D. 
Deering, and M. Leroy. 1997. Modelling BRDF and radiation regime of boreal and 
tropical forest. submitted to Remote Sensing of Environment.
Leblanc, S.G., P. Bicheron, J.M. Chen, M. Leroy, and J. Cihlar. 1997. 
Investigation of directional reflectance in boreal forests with an improved 4-
scale model and airborne POLDER data, IEEE Transactions on Geoscience and Remote 
Sensing, (submitted).
Leroy, M. and F.M. Bron. 1996. Surface reflectance angular signatures from 
airborne POLDER data. Remote Sensing of Environment, 57, pp. 97-107.
Leroy, M., Bicheron, P., and Hautecoeur, O. 1997. An algorithm of LAI and FAPAR 
retrieval to be used with spaceborne POLDER/ADEOS data. In 7th International 
Symposium - Physical Measurements and Signatures in Remote Sensing, Courchevel, 
France.
Sellers, P.and F. Hall. 1994. Boreal Ecosystem-Atmosphere Study: Experiment 
Plan. Version 1994-3.0, NASA BOREAS Report (EXPLAN 94). 

Sellers, P.and F. Hall. 1996. Boreal Ecosystem-Atmosphere Study: Experiment 
Plan. Version 1996-2.0, NASA BOREAS Report (EXPLAN 96). 

Sellers, P., F. Hall, and K.F. Huemmrich. 1996. Boreal Ecosystem-Atmosphere 
Study: 1994 Operations. NASA BOREAS Report (OPS DOC 94). 

Sellers, P., F. Hall, and K.F. Huemmrich. 1997. Boreal Ecosystem-Atmosphere 
Study: 1996 Operations. NASA BOREAS Report (OPS DOC 96). 

Sellers, P., F. Hall, H. Margolis, B. Kelly, D. Baldocchi, G. den Hartog, J. 
Cihlar, M.G. Ryan, B. Goodison, P. Crill, K.J.Ranson, D. Lettenmaier, and D.E. 
Wickland. 1995. The boreal ecosystem-atmosphere study (BOREAS): an overview and 
early results from the 1994 field year. Bulletin of the American Meteorological 
Society. 76(9):1549-1577. 

Sellers, P.J., F.G. Hall, R.D. Kelly, A. Black, D. Baldocchi, J. Berry, H. 
Margolis, M. Ryan, J. Ranson, P.M. Crill, D.P. Lettenmeier, J. Cihlar, J. 
Newcomer, D. Halliwell, D. Fitzjarrald, P.G. Jarvis, S.T. Gower, D. Williams, B. 
Goodison, D.E. Wickland, and F.E. Guertin. 1997.  BOREAS in 1997: Scientific 
results, experiment overview and future directions.  Journal of Geophysical 
Research, 102(D24): 28,731-28,770. 

17.3 Archive/DBMS Usage Documentation

None.

18. Glossary of Terms

None.

19. List of Acronyms

    6S      - Second Simulation of the Satellite signal in the Solar system
    ARC     - Ames Research Center
    BOREAS  - BOReal Ecosystem-Atmosphere Study
    BORIS   - BOREAS Information System
    BPDF    - Bidirectional Polarization Distribution Function
    BRDF    - Bidirectional Reflectance Distribution Function
    BSQ     - Band Sequential
    CCD     - Change Coupled Device
    DAAC    - Distributed Active Archive Center
    EOS     - Earth Observing System
    EOSDIS  - EOS Data and Information System
    FOV     - Field-of-View
    GSFC    - Goddard Space Flight Center
    IFC     - Intensive field Campaign
    LAI     - Leaf Area Index
    LOA     - Laboratoire d'Optique Atmospherique
    NAD83   - North American Datum of 1983
    NASA    - National Aeronautics and Space Administration
    NSA     - Northern Study Area
    OA      - Old Aspen
    OBS     - Old Black Spruce
    OJP     - Old Jack Pine
    ORNL    - Oak Ridge National Laboratory
    PANP    - Prince Albert National Park
    POLDER  - POLarization and Directionality of Earths Reflectances
    RSS     - Remote Sensing Science
    SSA     - Southern Study Area
    URL     - Uniform Resource Locator
    UTM     - Universal Transverse Mercator
    YJP     - Young Jack Pine

20. Document Information

20.1 Document Revision Date

     Written: 12-Sep-1996
     Updated: 07-May-1999

20.2 Document Review Date(s)

     BORIS Review: 06-May-1999
     Science Review:

20.3 Document ID

20.4 Citation

Acknowledge Marc Leroy and Patrice Bicheron (CESBIO, Toulouse), and Franois-
Marie Bron (LMCE, Saclay) for providing the POLDER data. Thank LOA (Lille) for 
providing the POLDER instrument. Cite relevant publications (see Section 17).

If using data from the BOREAS CD-ROM series, also reference the data as:
   Leroy, Marc, Bron, F. M.,  Bicheron, P., Hautecoeur, O., "Airborne 
   Remote Sensing Measurements with the POLDER Instrument" in Collected 
   Data of The Boreal Ecosystem-Atmosphere Study.  Eds. J. Newcomer, D. 
   Landis, S. Conrad, S. Curd, K. Huemmrich, D. Knapp, A.Morrell, J. 
   Nickeson, A. Papagno, D. Rinker, R. Strub, T. Twine, F. Hall, and P. 
   Sellers.  CD-ROM. NASA, 2000.

Also, cite the BOREAS CD-ROM set as:
	Newcomer, J., D. Landis, S. Conrad, S. Curd, K. Huemmrich, D. Knapp, A. 
Morrell, J. Nickeson, A. Papagno, D. Rinker, R. Strub, T. Twine, F. Hall, 
and P. Sellers, eds. Collected Data of The Boreal Ecosystem-Atmosphere 
Study. CD-ROM. NASA, 2000.

20.5 Document Curator

20.6 Document URL

Keywords:

POLDER
Bidirectional Reflectance
Aircraft Sensors
RSS20_POLDER_C130_Img.doc
06/09/99