The SE-590 Reflectance Factors and Radiances from UNL Data Set contains surface reflectance and viewing angle data that was collected at three sites within the FIFE study area via a SE590 mounted on a portable mast. All measurements were made on eleven days between July 15 and August 11, 1989. Measurements were typically coordinated with aircraft and/or satellite overpasses. On days when measurements were not made the bare soil was covered with a plastic mulch that allowed moisture to penetrate the surface but hindered the regrowth of the vegetation. Solar radiation data at or near the specific site should be used to screen possible times of variable cloud cover.
Canopy, illumination, and viewing geometry are critical in determining the amount of reflected radiation received at the sensor. The measurements were predominantly made in the solar principal plane since the greatest variation in observed reflected radiation is expected to occur in that plane due to extremes in sunlit and shaded portions of the canopy (Norman and Walthall 1985). Reflected radiation measurements were converted to radiances and reflectance factor. Reflected radiation from a field reference panel corrected for non-perfect reflectance and sun angle was used as an estimate of the ideal Lambertian standard surface (Walter-Shea and Biehl 1990).
SE-590 Ground Data: UNL (FIFE).
(SE-590 Reflectance Factors and Radiances from UNL ).
The SE-590 Reflectance Factors and Radiances from UNL Data Set contains surface reflectance and viewing angle data that was collected at three sites within the FIFE study area.
Surface reflectance and viewing angles.
The SE590 was mounted on a portable mast in order to achieve a spatial and temporal sampling at sites 906 (2133-BBS), 916 (4439-BBS), and 966 (2437-BBS). Measurements were periodically collected with the SE590 on the portable mast over a halon panel. Solar radiation data at or near the specific site should be used to screen possible times of variable cloud cover.
At sites 906 (2133-BBS) and 916 (4439-BBS), six (6) plots were identified. One of the 6 plots (plot number 999) was a bare soil plot prepared with a weed trimmer that removed the surface vegetation but left the root systems intact. On days when measurements were not made the bare soil was covered with a plastic mulch that allowed moisture to penetrate the surface but hindered the regrowth of the vegetation. The portable mast was always aligned in the solar principal plane at the above sites. Measurements were typically coordinated with aircraft and/or satellite overpasses.
At site 966 (2437-BBS), sixteen (16) plots were identified. One of these plots was a bare soil plot that was treated in the aforementioned manner. At this site the portable mast was aligned parallel to the aspect of each plot (i.e., north-south or east-west). Plot number 991 was bare measured in north-south plane, 992 was bare soil measured in east-west plane.
All measurements were made on eleven days between July 15 and August 11, 1989.
SE590_GROUND_UNL_DATA.
Blaine L. Blad, Professor and Head
Elizabeth A. Walter-Shea, Asst. Professor
University of Nebraska
Measuring and Modeling Near-Surface Reflected and Emitted Radiation Fluxes at the FIFE Site.
Contact 1:
Cynthia J. Hays
107 LWC
Lincoln, NE
68583-0728
(402)472-6701
Contact 2:
Mark A. Mesarch
Lincoln, NE
(402)472-5904
AGME012@129.93.200.1
Contact 3:
Elizabeth A. Walter-Shea
Lincoln, NE
(402)472-1553
AGME012@129.93.200.1
The Leaf Area Index and PAR Determined from the UNL Light Bar Data were collected under the direction of B.L. Blad and E.A. Walter-Shea at the University of Nebraska. The dedicated efforts of C.J. Hays and M.A. Mesarch in the collection and preparation of these data is particularly appreciated.
Light radiation striking a vegetative canopy interacts with individual phytoelements (leaves, stems, branches) and the underlying substrate. The interaction depends on light quality, radiative form (direct or diffuse), illumination incidence angle, vegetative component optical properties and canopy architecture. Radiation is reflected, transmitted or absorbed. Researchers have shown that phytoelements and substrates are not perfect Lambertian reflectors, i.e., they do not reflect equally in all directions (Breece and Holmes 1971; Walter-Shea et al., 1989; Brakke et al., 1989; Irons et al., 1989). The amount of leaf area and leaf angle distribution will determine the amount of vegetation and substrate that is sunlit and shaded. The amount of vegetative and substrate and respective amounts of sunlit and shaded components in a scene will vary depending upon the angle at which it is viewed, i.e., the canopy is itself a non-Lambertian surface. Thus, canopy, illumination and viewing geometry are critical in determining the amount of reflected radiation received at the sensor. Our measurements were predominantly made in the solar principal plane since the greatest variation in observed reflected radiation is expected to occur in that plane due to extremes in sunlit and shaded portions of the canopy (Norman and Walthall 1985).
Reflected radiation measurements were converted to radiances and reflectance factor. The reflectance factor is the ratio of the target reflected radiant flux to an ideal radiant flux reflected by an ideal Lambertian standard surface irradiated in exactly the same way as the target. Reflected radiation from a field reference panel corrected for non-perfect reflectance and sun angle was used as an estimate of the ideal Lambertian standard surface (Walter-Shea and Biehl 1990).
The Spectron Engineering SE590 is a portable battery operated spectroradiometer consisting of a CE500 data analyzer/logger controller, CE390 spectral detector head and an external battery charger/power supply. The CE500 is a self contained microprocessor-based controller which processes the signal from the head, amplifying and digitizing it with 12 bit resolution. For each spectral scan, the controller actuates the CE390 shutter, measures and stores the dark current, calculates optimum integration time, acquires the spectrum and automatically subtracts the noise for all 256 spectral elements. A series of scans can be taken and automatically averaged. The spectrum is stored in a double precision register which saves the entire 12-bit binary spectra until it is transmitted through the RS-232C port. The spectral detector head uses a defraction grating as the dispersive element; the spectrum is imaged onto a 256 element photodiode array. Each element integrates simultaneously acquiring the spectrum in a fraction of a second The interconnect cable from the spectral head to the controller couples the spectral signals to the controller, timing and control signals to the head. A shutter in the head, operated by the controller closes the light path for dark current measurements. For further information consult the SE590 operating manual. Serial Number 1571 was used.
Ground-based.
The SE590 was mounted 3.4 m above the soil surface on a portable, pointable mast which allowed the SE590 to view approximately the same surface area, regardless of the view zenith angle.
Not applicable.
Surface radiances and reflectance factors from 400 to 1000 nm at every 5 nm.
The SE590 spectral detector head uses a defraction grating as the dispersive element; the spectrum is imaged onto a 256 element photodiode array. Each element integrates simultaneously acquiring the spectrum in a fraction of a second.
The SE590 was mounted on a portable, pointable mast. The mast allowed the SE590 to view approximately the same surface area, regardless of the view zenith angle. The SE590 was located at 3.4 m above the soil surface with a 15 degree field-of-view and a spot size of approximately 0.75 m diameter at nadir.
Spectron Engineering, Inc.
255 Yuma Court
Denver, Colorado 80223
(303) 733-1060
A post-season radiance calibration was supplemented by daily stability checks during the IFC-5 using a 30 cm integrating sphere operated at two lamp intensities. The 30 cm integrating sphere was located in an environmental chamber at the Kansas State Evapotranspiration Laboratory that was kept at a near constant ambient temperature during the checks.
Temperature sensitivity data were obtained when the chamber was not being used for stability checks. No corrections were made for the temperature sensitivity (Blad et al., 1990). A post-season wavelength calibration was performed. The post-season radiance and wavelength calibrations were performed at Goddard Space Flight Center.
Each SE590 has a unique wavelength associated with each of its 252 bands. So that wavelength to wavelength comparisons could be made among SE-590s used at FIFE a cubic spline interpolation was applied to the 252 bands to standardize the wavelengths to every 5 nm from 400 to 1000 nm.
Results from the temperature dependency data indicated that measurements at wavelength of 1000 nm may result in discrepancies of approximately 50 [Watts][m^-2] [sr^-1][um^-1] if the instrument temperature varies for 16 to 43.5 degree C (Blad et al., 1990).
Daily stability checks were only performed during the IFC-5 period. A post-season wavelength and radiance calibration were performed at Goddard Space Flight Center.
Calibration coefficients used for data reduction (Kim 1990).
SE-590 Wavelength SE-590 Wavelength
Band (nm) Band (nm)
------ ----------- ------ -----------
1.0 374.46 51.0 504.70
2.0 377.00 52.0 507.65
3.0 379.52 53.0 510.61
4.0 382.01 54.0 513.57
5.0 384.47 55.0 516.53
6.0 386.92 56.0 519.49
7.0 389.34 57.0 522.46
8.0 391.75 58.0 525.42
9.0 394.15 59.0 528.39
10.0 396.53 60.0 531.35
11.0 398.91 61.0 534.31
12.0 401.28 62.0 537.27
13.0 403.64 63.0 540.22
14.0 406.00 64.0 543.16
15.0 408.36 65.0 546.10
16.0 410.72 66.0 549.03
17.0 413.09 67.0 551.96
18.0 415.47 68.0 554.87
19.0 417.85 69.0 557.78
20.0 420.25 70.0 560.69
21.0 422.66 71.0 563.59
22.0 425.08 72.0 566.48
23.0 427.53 73.0 569.37
24.0 429.99 74.0 572.25
25.0 432.48 75.0 575.13
26.0 435.00 76.0 578.00
27.0 437.54 77.0 580.87
28.0 440.12 78.0 583.74
29.0 442.71 79.0 586.60
30.0 445.34 80.0 589.46
31.0 447.98 81.0 592.32
32.0 450.66 82.0 595.17
33.0 453.35 83.0 598.03
34.0 456.07 84.0 600.88
35.0 458.80 85.0 603.73
36.0 461.56 86.0 606.58
37.0 464.34 87.0 609.43
38.0 467.13 88.0 612.28
39.0 469.94 89.0 615.13
40.0 472.77 90.0 617.98
41.0 475.61 91.0 620.83
42.0 478.47 92.0 623.69
43.0 481.34 93.0 626.54
44.0 484.23 94.0 629.40
45.0 487.12 95.0 632.26
46.0 490.03 96.0 635.12
47.0 492.95 97.0 637.99
48.0 495.87 98.0 640.86
49.0 498.81 99.0 643.73
50.0 501.75
SE-590 Wavelength SE-590 Wavelength
Band (nm) Band (nm)
------ ----------- ------ -----------
100.0 646.61 150.0 804.58
101.0 649.49 151.0 807.73
102.0 652.37 152.0 810.80
103.0 655.27 153.0 813.78
104.0 658.16 154.0 816.69
105.0 661.07 155.0 819.53
106.0 663.98 156.0 822.33
107.0 666.89 157.0 825.08
108.0 669.82 158.0 827.82
109.0 672.75 159.0 830.54
110.0 675.68 160.0 833.27
111.0 678.63 161.0 836.01
112.0 681.59 162.0 838.78
113.0 684.55 163.0 841.60
114.0 687.52 164.0 844.47
115.0 690.51 165.0 847.40
116.0 693.50 166.0 850.38
117.0 696.50 167.0 853.40
118.0 699.51 168.0 856.47
119.0 702.54 169.0 859.58
120.0 705.57 170.0 862.73
121.0 708.63 171.0 865.91
122.0 711.69 172.0 869.13
123.0 714.77 173.0 872.37
124.0 717.87 174.0 875.64
125.0 720.98 175.0 878.93
126.0 724.12 176.0 882.24
127.0 727.27 177.0 885.56
128.0 730.44 178.0 888.90
129.0 733.63 179.0 892.24
130.0 736.85 180.0 895.59
131.0 740.09 181.0 898.94
132.0 743.35 182.0 902.29
133.0 746.64 183.0 905.64
134.0 749.96 184.0 908.97
135.0 753.30 185.0 912.30
136.0 756.67 186.0 915.61
137.0 760.07 187.0 918.91
138.0 763.50 188.0 922.20
139.0 766.96 189.0 925.48
140.0 770.44 190.0 928.74
141.0 773.94 191.0 932.00
142.0 777.44 192.0 935.24
143.0 780.93 193.0 938.48
144.0 784.42 194.0 941.71
145.0 787.88 195.0 944.94
146.0 791.31 196.0 948.16
147.0 794.71 197.0 951.37
148.0 798.06 198.0 954.58
149.0 801.35 199.0 957.79
SE-590 Wavelength SE-590 Wavelength
Band (nm) Band (nm)
------ ----------- ------ -----------
200.0 960.99 227.0 1049.86
201.0 964.20 228.0 1053.36
202.0 967.40 229.0 1056.87
203.0 970.61 230.0 1060.41
204.0 973.81 231.0 1063.98
205.0 977.02 232.0 1067.57
206.0 980.23 233.0 1071.18
207.0 983.44 234.0 1074.83
208.0 986.66 235.0 1078.50
209.0 989.89 236.0 1082.20
210.0 993.12 237.0 1085.93
211.0 996.36 238.0 1089.69
212.0 999.60 239.0 1093.48
213.0 1002.86 240.0 1097.30
214.0 1006.12 241.0 1101.16
215.0 1009.40 242.0 1105.05
216.0 1012.69 243.0 1108.98
217.0 1015.99 244.0 1112.94
218.0 1019.30 245.0 1116.93
219.0 1022.63 246.0 1120.97
220.0 1025.97 247.0 1125.04
221.0 1029.33 248.0 1129.15
222.0 1032.70 249.0 1133.31
223.0 1036.10 250.0 1137.50
224.0 1039.51 251.0 1141.73
225.0 1042.94 252.0 1146.01
226.0 1046.39
Wavelength Gain Wavelength Gain
nm mw/cm**2/sr/um nm mw/cm**2/sr/um
---------- -------------- ---------- --------------
400 263.633 700 350.783
405 274.057 705 351.602
410 282.613 710 354.681
415 296.082 715 358.079
420 303.871 720 360.935
425 312.753 725 364.852
430 324.930 730 371.416
435 332.479 735 368.823
440 339.977 740 365.294
445 345.739 745 360.659
450 354.622 750 355.083
455 365.716 755 349.410
460 374.271 760 345.561
465 375.009 765 340.358
470 378.029 770 334.961
475 384.020 775 331.620
480 390.908 780 328.776
485 395.546 785 326.009
490 398.697 790 321.703
495 401.076 795 318.355
500 404.482 800 315.319
505 409.679 805 309.614
510 413.277 810 302.738
515 417.860 815 294.983
520 419.434 820 285.112
525 422.846 825 275.076
530 424.758 830 267.174
535 424.648 835 259.284
540 427.125 840 253.517
545 431.156 845 247.698
550 427.081 850 243.706
555 419.876 855 241.022
560 416.169 860 239.341
565 418.159 865 238.080
570 420.895 870 234.559
575 425.116 875 229.539
580 430.024 880 223.907
585 433.456 885 217.964
590 435.884 890 211.060
595 434.030 895 203.281
600 428.958 900 195.992
605 423.899 905 188.603
610 421.058 910 181.105
615 423.795 915 173.707
620 428.056 920 166.607
625 428.043 925 158.849
630 424.601 930 151.206
635 420.466 935 146.534
640 413.988 940 140.942
645 409.616 945 134.797
650 406.709 950 128.332
655 401.884 955 122.288
660 393.546 960 115.972
665 387.686 965 110.053
670 379.607 970 103.848
675 369.267 975 97.878
680 359.933 980 91.951
685 354.666 985 85.684
690 352.157 990 80.127
695 350.419 995 74.694
1000 70.086
The SE590 was mounted on a pointable, portable mast at a height of 3.4 m above the soil surface. The mast allowed the sensor to view the same surface area regardless of the viewing direction. A reference panel was positioned at a height of approximately 1 m above the soil surface. This panel was located within easy access to the plots and was measured to estimate the incoming radiation needed for data reduction. A measurement of the reference panel was made at the beginning of the measurement period. The mast was then positioned within a plot and aligned in the solar principal plane at sites 906 (2133-ECA) and 916 (4439-ECV) or parallel to the aspect of the plot (i.e., north-south or east-west) at site 966 (2437-BBS). Measurements were made at nadir and 20, 35 and 50 degree view zenith angles either side of nadir in the azimuthal plant of interest. At site 966 (2437-BBS) an additional view zenith angle perpendicular to the slope of the plot was included. An average of four SE590 scans were recorded. View zenith angles were measured by an inclinometer mounted on the mast. The mast was moved from plot to plot. After 20 to 25 minutes another measurement of the reference panel was made and the above procedure was repeated ending with a measurement of the reference panel.
Not available.
The FIFE study area with areal extent of 15 km by 15 km, is located south of the Tuttle Reservoir and Kansas River, and about 10 km from Manhattan, Kansas, USA. The northwest corner of the area has UTM coordinates of 4,334,000 Northing and 705,000 Easting in UTM Zone 14.
All view-zenith angles were measured with respect to gravity not in relation to the slope of the plot.
Plots at sites 906 (2133-BBS) and 916 (4439-BBS) were located northeast of the Wind Aligned Blob (WAB) site (Sellers et al., 1989). A topography file containing the northing and easting of the plots at each site except for site 966 (2437-BBS), is available in the GRABBAG section of FIFE CD-ROM Volume 1 in the UNL directory, in file UNL_PLOT.T89. This file also includes slope, aspect, soil depth and vegetative height of the plots, for all sites.
Measurements were made at the following three locations within the FIFE study area:
SITEGRID STN NORTHING EASTING LATITUDE LONGITUDE ELEV SLOPE ASPECT
-------- --- -------- ------- -------- --------- ---- ----- ------
2133-BBS 906 4329726 711604 39 05 34 -96 33 12 443 1 TOP
2437-BBS 966 4329150 712375 39 05 15 -96 32 41
4439-BBS 916 4325193 712773 39 03 06 -96 32 28 443 2 N
Not available.
The footprint (surface area viewed by the SE590 at a height of 3.4 meters from the soil surface) had a diameter of 0.75 m at nadir and changed with view zenith angle. The plot size was approximately 3 m x 3 m.
Not available.
Not available.
Measurements on all the plots at sites 906 (2133-BBS) and 916 (4439-BBS) required 30 minutes or less and were coordinated with aircraft and satellite overpasses. Measurements of all the plots at site 966 (2437-BBS) required 2 to 3 hours.
Not available.
The measurement time ranged from 1358 to 2219 GMT. Measurements were not continuously made over this range but were in discrete measurement periods depending on the number of plots in a site and coordination with aircraft and satellite overpasses. Data were obtained at only one site per day. A maximum of five (5) discrete measurement periods throughout the day was obtained. Measurements were made between June 15, 1989 and August 11, 1989. During this period measurements were made on the following 11 days:
OBS_DATE:
The SQL definition for this table is found in the SE_UNL.TDF file located on FIFE CD-ROM Volume 1.
Parameter/Variable Name
Parameter/Variable Description Range Units Source
SITEGRID_ID This is a FIS grid location code. Site grid codes (SSEE-III) give the south (SS) and east (EE) cell number in a 100 x 100 array of 200 m square cells. The last 3 characters (III) are an instrument identifier.
STATION_ID The station ID designating the location of the observations.
OBS_DATE The date of the observations, in the format (DD-MMM-YY).
OBS_TIME The start time of the observation [GMT] in GMT. The format is (HHMM).
VIEW_AZIM_ANG The view azimuth angle. With [degrees North=0, East=90 from North]
VIEW_ZEN_ANG The view zenith angle of the [degrees] observations. With a nadir view, view zenith angle=0
SOLAR_AZIM_ANG The solar azimuth angle. With [degrees North=0, East=90 from North]
SOLAR_ZEN_ANG The solar zenith angle. [degrees]
PLOT The identification number assigned to a specific plot within a site. Plots numbered 999 are bare soil.
SLOPE For the slope site this column contains measurements of the slope of the measured plot in degrees.
ASPECT For the slope site this column contains measurements of the aspect of the measured plot in degrees, with north=0 and east=90. With aspect defined as the direction a line perpendicular from the surface points.
WAVLEN The wavelength at which the [microns] observation was made.
REFL The average percent reflectance. [percent] Radiance values have been resampled using a cubic spline interpolation then ratioed with calibration panel data.
FIFE_DATA_CRTFCN_CODE The FIFE Certification Code for * the data, in the following format: CPI (Certified by PI), CPI-??? (CPI - questionable data).
LAST_REVISION_DATE The last revision date for the data, in the format (DD-MMM-YY).
Footnote:
Valid levels
The primary certification codes are:
The certification code modifiers are:
SITEGRID_ID STATION_ID OBS_DATE OBS_TIME PLOT SLOPE
----------- ---------- --------- ---------- ---------- ----------
4439-BBS 916 04-AUG-89 1730 1
4439-BBS 916 04-AUG-89 1730 1
4439-BBS 916 04-AUG-89 1730 1
4439-BBS 916 04-AUG-89 1730 1
ASPECT VIEW_AZIM_ANG VIEW_ZEN_ANG SOLAR_AZIM_ANG SOLAR_ZEN_ANG
---------- ------------- ------------ -------------- -------------
325 0 146.9 25.2
325 0 146.9 25.2
325 0 146.9 25.2
325 0 146.9 25.2
WAVLEN REFL FIFE_DATA_CRTFCN_CODE LAST_REVISION_DATE
---------- ---------- --------------------- ------------------
.4 2.23 CPI 11-JAN-91
.405 2.21 CPI 11-JAN-91
.41 2.25 CPI 11-JAN-91
.415 2.34 CPI 11-JAN-91
Measurements were not continuously made but were in discrete measurement periods depending on the number of plots in a site and coordination with aircraft and satellite overpasses. Data were obtained at only one site per day. A maximum of five (5) discrete measurement periods throughout the day was obtained.
A general description of data granularity as it applies to the IMS appears in the EOSDIS Glossary.
The CD-ROM file format consists of numerical and character fields of varying length separated by commas. The character fields are enclosed with a single apostrophe. There are no spaces between the fields. Each file begins with five header records. Header records contain the following information:
Each field represents one of the attributes listed in the chart in the Data Characteristics Section and described in detail in the TDF file. These fields are in the same order as in the chart.
where:
where:where:
where:
A Lapsphere molded halon reference panel was used. This panel was calibrated in September 1989 by the University of Nebraska following the procedure of Jackson et al. (1987).
The calibration yields the coefficients to a third order polynomial of the form:
where:
The result of this equation RFp(t,j) is used in equation [4].
Panel coefficients
-----------------------------
Wave-
Length C0 C1 C2 C3
------ ------------- ------------- -------------- -------------
400 0.1020691E+01 0.2307796E-02 -0.7176625E-04 0.2028643E-06
405 0.1023635E+01 0.2348937E-02 -0.7409656E-04 0.2168063E-06
410 0.1027976E+01 0.1691810E-02 -0.5849818E-04 0.1115234E-06
415 0.1026675E+01 0.1986200E-02 -0.6609871E-04 0.1656263E-06
420 0.1028462E+01 0.1928542E-02 -0.6473542E-04 0.1522611E-06
425 0.1030961E+01 0.1599423E-02 -0.5722518E-04 0.1032186E-06
430 0.1032524E+01 0.1483927E-02 -0.5489080E-04 0.9058423E-07
435 0.1031159E+01 0.1572472E-02 -0.5582624E-04 0.8927227E-07
440 0.1033558E+01 0.1498712E-02 -0.5456564E-04 0.8286727E-07
445 0.1033324E+01 0.1569419E-02 -0.5690657E-04 0.1039715E-06
450 0.1036139E+01 0.1305071E-02 -0.5105510E-04 0.6360571E-07
455 0.1038211E+01 0.1159643E-02 -0.4794833E-04 0.4357352E-07
460 0.1036826E+01 0.1354819E-02 -0.5326012E-04 0.8434483E-07
465 0.1038920E+01 0.1132739E-02 -0.4769623E-04 0.4260698E-07
470 0.1039643E+01 0.1113157E-02 -0.4713262E-04 0.3869216E-07
475 0.1039233E+01 0.1153365E-02 -0.4839558E-04 0.4917332E-07
480 0.1040030E+01 0.1155133E-02 -0.4909308E-04 0.5609697E-07
485 0.1041885E+01 0.1005832E-02 -0.4571612E-04 0.3395124E-07
490 0.1039826E+01 0.1166439E-02 -0.4888924E-04 0.5190591E-07
495 0.1040985E+01 0.1065573E-02 -0.4634565E-04 0.3235320E-07
500 0.1042588E+01 0.9224978E-03 -0.4325799E-04 0.1215631E-07
505 0.1044681E+01 0.7519039E-03 -0.3927152E-04 -0.1493404E-07
510 0.1043211E+01 0.8573297E-03 -0.4200791E-04 0.4340810E-08
515 0.1042012E+01 0.9367443E-03 -0.4354084E-04 0.1444452E-07
520 0.1041645E+01 0.9941544E-03 -0.4520349E-04 0.2767669E-07
525 0.1042760E+01 0.8751338E-03 -0.4183103E-04 -0.2532645E-09
530 0.1044702E+01 0.6598454E-03 -0.3724032E-04 -0.2877237E-07
535 0.1042191E+01 0.9069606E-03 -0.4292930E-04 0.8617134E-08
540 0.1043134E+01 0.8160212E-03 -0.4042930E-04 -0.1107292E-07
545 0.1041051E+01 0.9394131E-03 -0.4364209E-04 0.1395316E-07
550 0.1043180E+01 0.7566459E-03 -0.3943769E-04 -0.1579043E-07
555 0.1044188E+01 0.7296551E-03 -0.3916740E-04 -0.1698103E-07
560 0.1043210E+01 0.7575643E-03 -0.3901382E-04 -0.2262007E-07
565 0.1042763E+01 0.8187740E-03 -0.4061343E-04 -0.8930165E-08
570 0.1044980E+01 0.6854801E-03 -0.3789858E-04 -0.2640262E-07
575 0.1043569E+01 0.7628911E-03 -0.3926709E-04 -0.1867208E-07
580 0.1042724E+01 0.8381633E-03 -0.4131085E-04 -0.4006738E-08
585 0.1042959E+01 0.7833779E-03 -0.4003083E-04 -0.1313729E-07
590 0.1042308E+01 0.8542608E-03 -0.4146493E-04 -0.4291500E-08
595 0.1043040E+01 0.7772386E-03 -0.3944546E-04 -0.2026909E-07
600 0.1044935E+01 0.6830641E-03 -0.3784099E-04 -0.2870515E-07
605 0.1045260E+01 0.6352458E-03 -0.3627764E-04 -0.4183683E-07
610 0.1044507E+01 0.7371207E-03 -0.3916481E-04 -0.1862948E-07
615 0.1044152E+01 0.7730190E-03 -0.3948137E-04 -0.1895644E-07
620 0.1043966E+01 0.7937066E-03 -0.4021111E-04 -0.1255158E-07
625 0.1044246E+01 0.7586920E-03 -0.3928547E-04 -0.1985262E-07
630 0.1045597E+01 0.6534198E-03 -0.3650992E-04 -0.4194394E-07
635 0.1044604E+01 0.8030013E-03 -0.4020498E-04 -0.1586309E-07
640 0.1044003E+01 0.8092978E-03 -0.4004213E-04 -0.1822999E-07
645 0.1044257E+01 0.7523490E-03 -0.3898273E-04 -0.2239451E-07
650 0.1045403E+01 0.6644642E-03 -0.3657396E-04 -0.4320698E-07
655 0.1046331E+01 0.6109984E-03 -0.3529197E-04 -0.5168750E-07
660 0.1044507E+01 0.8011676E-03 -0.3970652E-04 -0.2104697E-07
665 0.1046092E+01 0.5774825E-03 -0.3407302E-04 -0.6149129E-07
670 0.1046652E+01 0.6211065E-03 -0.3607046E-04 -0.4385477E-07
675 0.1043847E+01 0.7546030E-03 -0.3838479E-04 -0.3292595E-07
680 0.1044203E+01 0.7235191E-03 -0.3768374E-04 -0.3605060E-07
685 0.1042028E+01 0.8885071E-03 -0.4118552E-04 -0.1339236E-07
690 0.1041722E+01 0.8982174E-03 -0.4130272E-04 -0.1182499E-07
695 0.1043119E+01 0.7811239E-03 -0.3854480E-04 -0.3111853E-07
700 0.1044344E+01 0.6963478E-03 -0.3671847E-04 -0.4454136E-07
705 0.1044987E+01 0.6712667E-03 -0.3628980E-04 -0.4698841E-07
710 0.1041283E+01 0.9727916E-03 -0.4312553E-04 -0.2159273E-08
715 0.1040946E+01 0.9864625E-03 -0.4347726E-04 0.1658801E-08
720 0.1040259E+01 0.1072143E-02 -0.4537162E-04 0.1533203E-07
725 0.1040856E+01 0.1005566E-02 -0.4269822E-04 -0.1164932E-07
730 0.1041606E+01 0.8903170E-03 -0.4111425E-04 -0.1515658E-07
735 0.1043015E+01 0.8589865E-03 -0.4066363E-04 -0.2088457E-07
740 0.1046650E+01 0.5306230E-03 -0.3325386E-04 -0.7159644E-07
745 0.1044990E+01 0.7686343E-03 -0.3913624E-04 -0.3107813E-07
750 0.1046234E+01 0.6327561E-03 -0.3658425E-04 -0.4737320E-07
755 0.1047823E+01 0.6211554E-03 -0.3718316E-04 -0.4056453E-07
760 0.1042600E+01 0.9254874E-03 -0.4231824E-04 -0.1316337E-07
765 0.1044418E+01 0.8084020E-03 -0.3931320E-04 -0.3034765E-07
770 0.1043483E+01 0.7766855E-03 -0.3781739E-04 -0.4062813E-07
775 0.1044584E+01 0.7153847E-03 -0.3646227E-04 -0.5397206E-07
780 0.1043379E+01 0.7074788E-03 -0.3665062E-04 -0.5043588E-07
785 0.1043978E+01 0.7381677E-03 -0.3829550E-04 -0.3632283E-07
790 0.1043675E+01 0.7494834E-03 -0.3794876E-04 -0.4191600E-07
795 0.1039806E+01 0.1037861E-02 -0.4525806E-04 0.1293397E-07
800 0.1043500E+01 0.9185881E-03 -0.4322741E-04 -0.1163219E-08
805 0.1042646E+01 0.8156832E-03 -0.3998216E-04 -0.2506371E-07
810 0.1046820E+01 0.4941361E-03 -0.3317775E-04 -0.6669556E-07
815 0.1040511E+01 0.1039870E-02 -0.4522509E-04 0.1189255E-07
820 0.1038469E+01 0.1295986E-02 -0.5196943E-04 0.6058429E-07
825 0.1042260E+01 0.9458050E-03 -0.4312630E-04 -0.3836924E-08
830 0.1045250E+01 0.7185282E-03 -0.3877058E-04 -0.2936804E-07
835 0.1045535E+01 0.6508042E-03 -0.3633434E-04 -0.4933092E-07
840 0.1037599E+01 0.1296161E-02 -0.5030810E-04 0.3964285E-07
845 0.1046608E+01 0.6270441E-03 -0.3644990E-04 -0.4800667E-07
850 0.1045323E+01 0.7754005E-03 -0.3969374E-04 -0.2803267E-07
855 0.1042171E+01 0.7959635E-03 -0.3869225E-04 -0.3927269E-07
860 0.1043839E+01 0.8561251E-03 -0.4141981E-04 -0.1528441E-07
865 0.1042140E+01 0.9965700E-03 -0.4448181E-04 0.4938349E-08
870 0.1050822E+01 0.1312364E-03 -0.2362573E-04 -0.1425405E-06
875 0.1043396E+01 0.7739614E-03 -0.3876894E-04 -0.3688082E-07
880 0.1045459E+01 0.8417810E-03 -0.4006278E-04 -0.3309392E-07
885 0.1045308E+01 0.8914825E-03 -0.4168651E-04 -0.2233586E-07
890 0.1041503E+01 0.1087362E-02 -0.4440085E-04 -0.1277023E-07
895 0.1044998E+01 0.9936822E-03 -0.4378704E-04 -0.8000492E-08
900 0.1044516E+01 0.9439814E-03 -0.4285062E-04 -0.1423759E-07
905 0.1051446E+01 0.2078550E-03 -0.2469360E-04 -0.1449934E-06
910 0.1039938E+01 0.1304500E-02 -0.5042315E-04 0.3517433E-07
915 0.1037042E+01 0.1588295E-02 -0.5866167E-04 0.1018471E-06
920 0.1049954E+01 0.5902972E-03 -0.3580553E-04 -0.5499579E-07
925 0.1049048E+01 0.7595964E-03 -0.4067645E-04 -0.2342711E-07
930 0.1050720E+01 0.7863740E-03 -0.4294367E-04 0.2288731E-08
935 0.1046086E+01 0.9521864E-03 -0.4349145E-04 -0.1004916E-07
940 0.1024226E+01 0.3142879E-02 -0.9418973E-04 0.3319447E-06
945 0.1034131E+01 0.1843622E-02 -0.6248886E-04 0.1157058E-06
950 0.1030182E+01 0.2473955E-02 -0.7645961E-04 0.1948248E-06
955 0.1031775E+01 0.2705489E-02 -0.8893934E-04 0.3228065E-06
960 0.1027560E+01 0.2148790E-02 -0.6621033E-04 0.1178804E-06
965 0.1034866E+01 0.2427981E-02 -0.7996300E-04 0.2375677E-06
970 0.1038287E+01 0.1697609E-02 -0.6165585E-04 0.1109473E-06
975 0.1035191E+01 0.1719718E-02 -0.5832063E-04 0.7156511E-07
980 0.1032137E+01 0.2116019E-02 -0.7136896E-04 0.1721857E-06
985 0.1019492E+01 0.3677361E-02 -0.1085873E-03 0.4309212E-06
990 0.1035775E+01 0.1490417E-02 -0.5273831E-04 0.1846581E-07
995 0.1031226E+01 0.2336911E-02 -0.7589278E-04 0.1936309E-06
1000 0.1022056E+01 0.3207516E-02 -0.9718610E-04 0.3552770E-06
Each SE590 has a unique wavelength associated with each of its 252 bands. So that wavelength to wavelength comparisons could be made among SE-590s used at FIFE a cubic spline interpolation was applied to the 252 bands to standardize the wavelengths to every 5 nm from 400 to 1000 nm.
Equation 1 was then used to change the corrected voltages to radiances. The gains and offsets for each MMR are listed in 5.2.3 (Kim 1990). Usage of Equations 2 and 3 is dependent on the measurement time interval of the reference panel. These equations interpolate the reference panel radiance output for the time of surface reflectance measurements. If measurements of the reference panel are made less then every 30 minutes equation 2 is then applied (Bauer et al., 1981). If the measurements of the reference panel are greater then 30 minutes apart then equation 3 is used. The reference panel reflectance factor for each surface measurement time is determined as explained in the Derivation Techniques and Algorithms Section. This provides a correction for the reference panel's non-Lambertian properties and the dependence on solar zenith angle. Equation 4 is then used to calculate the surface reflectance factor using surface and reference panel radiances and the reference panel reflectance factor.
None known at this revision.
None reported at this revision.
None.
Errors associated with the measurements can occur due to orientation of the SE590. The view zenith angle could only be measured to +/- 2 degrees and the view azimuth angle could only be measured to + or - 10 degrees.
The shadowing caused by the SE590 and other instruments on the portable mast is another source of error when measuring the "hot spot" area.
Variable cloud cover could be an error source with reflectance factors since the incoming radiation measurements were not made simultaneously with the surface measurements but are interpolated assuming clear sky conditions.
Comparison's have been made with PARABOLA, helicopter mounted radiometers and MMR measurements.
On days with variable cloud conditions the data should be used with caution. The AMS incoming solar radiation data at the site or nearby site should be consulted.
On clear days the measurements fall within the precision of the instrument and errors that were discussed in previous sections.
Not available at this revision.
Not available at this revision.
The data verification performed by the ORNL DAAC deals with the quality of the data format, media, and readability. The ORNL DAAC does not make an assessment of the quality of the data itself except during the course of performing other QA procedures as described below.
The FIFE data were transferred to the ORNL DAAC via CD-ROM. These CD-ROMs are distributed by the ORNL DAAC unmodified as a set or in individual volumes, as requested. In addition, the DAAC has incorporated each of the 98 FIFE tabular datasets from the CD-ROMs into its online data holdings. Incorporation of these data involved the following steps:
Each distinct type of data (i.e. "data set" on the CD-ROM), is accompanied by a documentation file (i.e., .doc file) and a data format/structure definition file (i.e., .tdf file). The data format files on the CD-ROM are Oracle SQL commands (e.g., "create table") that can be used to set up a relational database table structure. This file provides column/variable names, character/numeric type, length, and format, and labels/comments. These SQL commands were converted to SAS code and were used to create SAS data sets and subsequently to input data files directly from the CD-ROM into a SAS dataset. During this process, file names and directory paths were captured and metadata was extracted to the extent possible electronically. No files were found to be corrupted or unreadable during the conversion process.
Additional Quality Assurance procedures were performed as follows:
As errors are discovered in the online tabular data by investigators, users, or DAAC staff, corrections are made in cooperation with the principal investigators. These corrections are then distributed to users. CD-ROM data are corrected when re-mastering occurs for replenishment of CD-ROM stock.
Not available.
Before using reflectance factors the incoming radiation from the AMS station at the site or nearby site should be checked for possible cloud-induced error in reflectance factors.
Not available at this revision.
This data set can be used to characterize bi-directional reflectance factor distributions in the solar principal plane for a tall grass prairie; estimate surface albedo from bi-directional reflectance factor and radiance data; determine the variability of reflected and emitted fluxes in selected spectral wavebands as a function of topography, vegetative community and management practice; determine the influence of plant water status on surface reflectance factors; and determine sun angle affects on radiation fluxes.
The FIFE field campaigns were held in 1987 and 1989 and there are no plans for new data collection. Field work continues near the FIFE site at the Long-Term Ecological Research (LTER) Network Konza research site (i.e., LTER continues to monitor the site). The FIFE investigators are continuing to analyze and model the data from the field campaigns to produce new data products.
Software to access the data set is available on the all volumes of the FIFE CD-ROM set. For a detailed description of the available software see the Software Description Document.
ORNL DAAC User Services
Oak Ridge National Laboratory
Telephone: (865) 241-3952
FAX: (865) 574-4665
Email: ornldaac@ornl.gov
ORNL Distributed Active Archive Center
Oak Ridge National Laboratory
USA
Telephone: (865) 241-3952
FAX: (865) 574-4665
Email: ornldaac@ornl.gov
Users may place requests by telephone, electronic mail, or FAX. Data is also available via the World Wide Web at http://daac.ornl.gov.
FIFE data are available from the ORNL DAAC. Please contact the ORNL DAAC User Services Office for the most current information about these data.
The SE-590 Reflectance Factors and Radiances from UNL are available on FIFE CD-ROM Volume 1. The CD-ROM filename is as follows:
\DATA\SUR_REFL\SE5_UNL\GRIDxxxx\yyddd\ydddgrid.Unn
Where xxxx is the four digit code for the location within the FIFE site grid, yy is the last two digits of the year (e.g., 87 = 1987), and ddd is the day of the year, (e.g., 061 = sixty-first day in the year). Note: capital letters indicate fixed values that appear on the CD-ROM exactly as shown here, lower case indicates characters (values) that change for each path and file.
The format used for the filenames is: ydddgrid.Unn, where grid is the four-number code for the location within the FIFE site grid, y is the last digit of the year (e.g., 7 = 1987, and 9 = 1989), ddd is the day of the year, and nn is the number of spectra during a day, when all the spectra are ordered chronologically and all spectra for a minute are in the same file. The content of each file is described in the Data Characteristics Section.
Spectron Engineering, Inc. Operating Manual: SE590 field-portable data-logging spectroradiometer. Spectron Engineering. Denver, CO 80223.
Bauer, M.E., B.F. Robinson, C. Daughtry, and L.L. Biehl. 1981. Field Measurement Workshop. Oct. 14-16, Laboratory for application of Remote Sensing. Purdue University. Lafayette, Indiana.
Blad, B.L., E.A. Walter Shea, C.J. Hays, and M.A. Mesarch. 1990. Calibration of field reference panel and radiometers used in FIFE 1989. AgMet Progress Report 90-3. Department of Agricultural Meteorology. University of Nebraska-Lincoln. Lincoln, Nebraska 68583-0728.
Brakke, T.W., J.A. Smith, and J. M. 1989. Bi-directional scattering of light from tree leaves. Remote Sensing of Environment. 29:175-183.
Breece, H.T. III and R.A. Holmes. 1971. Bi-directional scattering characteristics of healthy green soybean and corn leaves in vivo. Applied Optics. 10:119-127.
Irons, J.R., R.A. Weismiller, and G.W. Peterson. 1989. Soil reflectance In G. Asrar (ed.). Theory and Applications of Optical Remote Sensing. John Wiley & Sons. New York. p.66-106.
Jackson, R.D., S.M. Moran, P.N. Slater, and S.F. Biggar. 1987. Field calibration of reference reflectance panels. Remote Sensing of Environment. 17:103-108.
Kim, M. 1990. personal communication. GSFC/NASA. Greenbelt, MD 20771.
Norman, J.M. and C.L.Walthall. 1985. Analysis of an empirical model for hemispherical albedo computation. Final Report for Contract. #S-19583-D.
Sellers, P.J. and F.G. Hall. 1989. FIFE-89 Experiment Plan. GSFC/NASA, Greenbelt, MD 20771.
Walter-Shea, E.A., J.M. Norman, and B.L. Blad. 1989. Bi-directional reflectance and transmittance in corn and soybean. Remote Sensing of Environment. 29:161-174.
Walter-Shea, E.A. and L.L. Biehl. 1990. Measuring vegetation spectral properties. Remote Sensing Review. 5:179-205.
Contact the EOS Distributed Active Archive Center (DAAC) at Oak Ridge National Laboratory (ORNL), Oak Ridge, Tennessee (see the Data Center Identification Section). Documentation about using the archive and/or online access to the data at the ORNL DAAC is not available at this revision.
A general glossary for the DAAC is located at Glossary.
A general list of acronyms for the DAAC is available at Acronyms.
April 24, 1994 (citation revised on October 16, 2002).
Warning: This document has not been checked for technical or editorial accuracy by the FIFE Information Scientist. There may be inconsistencies with other documents, technical or editorial errors that were inadvertently introduced when the document was compiled or references to preliminary data that were not included on the final CD-ROM.
Previous versions of this document have been reviewed by the Principal Investigator, the person who transmitted the data to FIS, a FIS staff member, or a FIFE scientist generally familiar with the data.
August 15, 1996.
ORNL-FIFE_SE_UNL.
Blad, B. L., and E. A. Walter-Shea. 1994. SE-590 Ground Data: UNL (FIFE). Data set. Available on-line [http://www.daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. Also published in D. E. Strebel, D. R. Landis, K. F. Huemmrich, and B. W. Meeson (eds.), Collected Data of the First ISLSCP Field Experiment, Vol. 1: Surface Observations and Non-Image Data Sets. CD-ROM. National Aeronautics and Space Administration, Goddard Space Flight Center, Greenbelt, Maryland, U.S.A. (available from http://www.daac.ornl.gov).
http://daac.ornl.gov/FIFE/Datasets/Surface_Radiation/SE-590_Ground_Data_UNL.html