180° pyrheliometers, 50–52. see also Pyranometers
3TIER, 96
A
Abbot silver-disk pyrheliometer, 44–46
Abbot, Charles Greeley, 36, 44
Absolute Cavity Pyrgeometer (ACP), 212
Absolute cavity radiometers (ACRs), 83
passive mode of operation of, 86–88
uncertainty analysis for calibration of, 88–90
Absorptivity, 31
ACRIM radiometer. See Active cavity radiometer irradiance monitor
ACRs. See Absolute cavity radiometers Active cavity radiometer irradiance monitor (ACRIM) radiometer, 69
AERONET, 245
water vapor retrieval method of, 246
Aerosol optical depth (AOD), 95
measurement of with sun radiometers, 242–245
Aerosol-scattered light, 161
AHF cavity radiometer. See Automatic Hickey–Frieden cavity radiometer
Air temperature
measurements of, 255
response times, 256
Albedo, 25
changes in as a function of wavelength and time, 195
definition of, 193
single scattering, 230
Alberti, Leon Battista, 260
Aldrich, Loyal Blaine, 36
All-sky brightness, 163
All-wave net radiometers, 218–220
Ambient temperature, 255
types of sensors for measuring, 256
Anemometers, 260
sonic, 263
Aneroid displacement transducers, 268
Angle of incidence response, black-disk
thermopile pyranometers, 117–119
Ångström electrical compensation pyrheliometer, 41–43
Ångström pyranometer, 47
Ångström Scale, 59
Ångström Tulipan pyrgeometer, 44
Ångström, Anders Knutsson, 47
Ångström, Knut, 41
Angular response
black-and-white pyranometers, 126–127
use of rotating shadowband radiometers to measure, 66
AOD. See Aerosol optical depth Aphelion, 8, 12
Astronomical unit, 227
Asymmetry parameter, 230
Atmospheric interactions
aerosol scattering and absorption, 229–231
Rayleigh scattering, 229
transmission of beam irradiance, 236–237
Atmospheric pressure, measuring, 267–270
Atmospheric Radiation Measurement (ARM) site, 99–100
Automated Surface Observing System (ASOS), 257
Automatic Hickey–Frieden (AHF) cavity radiometer, 67–69
Average monthly daily total (AMDT), 97
determination of, 18
B
Barometers, 268
Baseline Surface Radiation Network (BSRN), 97–98
net radiation measurements, 223
Beam irradiance, 2, 22–23, 78. See also Direct normal irradiance
(see also specific radiometers)
Beam radiation, measurement of, 36
Beam–global correlations, 302–304
Beer’s law, 180
Bidirectional reflectance distribution function (BRDF), 200–201
Black bodies
absorptivity and emissivity of, 30–31
emissivity of, 205
laboratory calibration, 209–210
Black-and-white pyranometers, 106, 124
lack of thermal offset of, 128
Black-disk thermopile pyranometers, 108–113
angle of incidence response of, 117–119
heat losses in, 109
response degradation of, 119–120
temperature dependence of, 120–121
Black-sky albedo, 200
Blocked skylight, geometrical correction for, 164
Bolometric sunshine receiver, 43–44
Boltzmann constant, 31
Boltzmann, Ludwig, 30
BORCAL. See Broadband Outdoor Radiation Calibration
BRDF. See Bidirectional reflectance distribution function
Broadband filter radiometry, 237–242
Broadband Outdoor Radiation Calibration (BORCAL), 5
calibration of pyranometers using, 153–156
Broadband pyrgeometers, 206–207
Broadband solar data, 27
Broadband solar irradiances, modeling of, 95
Broadband spectral measurements, 227
Bucking thermopiles, 106
Burning sunshine recorder, 39–40. see also Campbell–Stokes sunshine recorder
C
Calculated diffuse irradiance vs. shade disk diffuse, 165–166
Calibration
absolute cavity radiometers, 86–88
black-disk thermopile pyranometers, 114–115
indoor lamp vs. Langley plots, 244
photodiode-based pyranometers, 131–134
shade–unshade technique, 144–146
shade–unshade vs. summation techniques, 141
single-sensor net radiometers, 220
uncertainties for pyranometers, 149–150
uncertainty analysis for
uncertainty analysis for pyrheliometers, 88–90
Callendar, H. L., 43
Calorimetry, design of radiometers using, 44
Campbell, J. F., 39
Campbell–Stokes sunshine recorder, 38–41
Cartesian sun path charts, 321–331
Cat ears effect, 135, 139, 176–177
Cavity radiometers
PMOD model 8 (PMO8), 71
uncertainty analysis for calibration of, 88–90
Celestial equator, 9
Celsius (centigrade) scale, 255
Chappuis ozone band, 231
Chilled-mirror hygrometers, 265–266
Circumsolar radiation, 162
Clean Power Research, Solar Anywhere service of, 96
Clear skies, measurement of temperature of, 205–206
Clearness index, 142
Clock time, 16
Cloud particles, scattering due to, 161–162
Cloud-index-to-ghi conversion, 314
Clouds, lensing effect of, 23–24
Co-albedo, 230
Column water vapor, derivation of, 246–247
Combined uncertainty, 150, 152
Commission for Instruments and Methods of Observation (CIMO) guide, 255
Concentrating photovoltaic (CPV) systems, 78
Concentrating solar power (CSP) thermal systems, 78, 183
Confidence level, 150
Convective losses, effects of tilt on pyranometer responsivity due to, 185–186
Coordinated universal time. See UTC Corpuscular theory of light, 35
Corrections
methods for blocked skylight, 164–165
multifilter rating shadowband radiometer, 179–181
photodiode-based pyranometers, 134–142
photometers, 239
pyranometer calibration, 131–132, 134
Cotton Region Shelter, 257
CPV systems. See Concentrating photovoltaic systems Critical damping factor, 260
CSP thermal systems. See Concentrating solar power thermal systems Cup anemometers, 260–261
D
Dark current, 32
Data
Data loggers, communications and, 276–278
Daylighting illuminance, 28
calculation of, 16
DHI. See Diffuse horizontal irradiance
Diffraction, 36
Diffuse horizontal irradiance (DHI), 3, 22–23, 103
accuracy of measurements, 168–169
calibration of pyranometers for measurement of, 167–168
definition, 161
deriving measurements of from satellite data, 315
shaded-disk measurement of, 165
spectral characteristics of, 139
use of measurements of for PV system modeling, 189–191
use of MFRSR to measure, 179–181
use of rotating shadowband radiometers for measuring, 174–177
Diffuse irradiance
calculated vs. shade disk, 165–166
fixed shadowband measurements of, 163–165
angle of incidence for, 167–168
calibrating pyranometers used for, 144–146
photodiode-based pyranometers, 139–141
use of fixed shadowband pyranometers for, 163–165
use of rotating shadowband pyranometers for, 166–167
Diffuse pyranometers, calibration of, 167–168
Dines, H .W., 261
Direct normal irradiance (DNI), 2, 8, 22–23
accuracy of shade–unshade calibration and measurements of, 144
deriving measurements of from satellite data, 315
ground-based modeling of, 95
historical and current surface-measured data, 97–100
integrated, 79
measurement of 66,
(see also specific radiometers)
satellite model estimates of, 95–97
spectral characteristics of, 139
sun radiometers for measuring, 242–248
uncertainty analysis for rotating shadowband measurements of, 93–94
use of measurements of for PV system modeling, 189–191
use of MFRSR to measure, 179–181
use of MFRSRs to measure, 66
use of rotating shadowband radiometers for measuring, 174–177
use of rotating shadowband radiometers to measure, 80
Direct solar radiation, measurement of, 36
DNI. See Direct normal irradiance Doping, 31–32
Downwelling infrared radiation, 217
Dry bulb temperature, 256
E
Earth
rotation of, 9
Earth radiation budget (ERB) instrument, 69
Ecliptic plane, 9
Effective sky temperature, 110
Einstein, Albert, 106
EKO Instruments Co., Ltd. MF–11, 218
EKO Instruments Co., Ltd. pyrgeometer, 212–213
Electrical resistance hygrometers, 267
Electrical substitution cavity radiometers (ESRs), 69–70
Electromagnetic waves, 30
Energy flux, use of photodiodes to measure, 129
EoT. See Equation of time Eppley Laboratory, Inc.
automatic Hickey–Frieden cavity radiometer, 67–69
fixed shadowband, 164
normal incidence pyrheliometer, 56–57, 80–82, 116
precision infrared radiometer (PIR), 58–59, 207–208,
(See also Precision infrared radiometer) precision spectral pyranometer, 52–55, 111–112, 134
(See also Precision spectral pyranometer)
calculation of, 17
Equinoxes, 9
ERB instrument. See Earth radiation budget instrument
ESRs. See Electrical substitution cavity radiometers
Expanded uncertainty, 150
Extraterrestrial radiation, 8, 23. See also Incident solar radiation
Extraterrestrial solar spectrum, 227–228
F
Faculae, 35
Fixed shadowband measurements of diffuse irradiance, 163–165
Flat plate solar collectors, 78, 183
Forward-scattered radiation, 162
Four-sensor net radiometers, 222
Fresnel reflection, 189
G
Gage factor, 268
Geometric scattering limit, 138
Geostationary Operational Environmental Satellites (GOES), 95–96
Geostationary satellites, 311–312
GHI. See Global horizontal irradiance
Global horizontal irradiance (GHI), 3, 8, 22–23, 77, 217
deriving measurements of from satellites, 313
integrated, 79
measurement of, 36, 49, 103–108
(see also specific radiometers)
reference, 118
uncertainty of, 93
use of measurements of for PV system modeling, 189–191
use of MFRSR to measure, 179–181
use of rotating shadowband radiometers for measuring, 174–177
Global irradiance
measurement of with pyranometers, 103–104
reflected, 3
Global irradiance on tilted surfaces, 103. See also Global tilted irradiance
Global tilted irradiance (GTI), 103
calculation of, 183
use of measurements of for PV system modeling, 189–191
GMT. See Greenwich mean time GOES West geosynchronous orbit weather satellite, 278
Gorczynski, Ladislas, 48
Gray bodies, emissivity of, 205
Green vegetation, spectral albedo and, 195–198
Greenhouse effect, 8
Greenwich mean time (GMT), 16–17
Grimaldi, Francesco, 36
Gröbner, Julian, 212
Ground-based modeling of DNI, 95
Ground-based spectral infrared measurements, 205–206
Ground-reflected irradiance, 25, 183
effect of on measurement of tilted irradiance, 187–188
Grounding, 276
GTI. See Global tilted irradiance
Guide to the Expression of Uncertainty in Measurements (GUM), 89
GUM procedure, 149
application of the calibration of uncertainties of a pyranometer, 153–156
Gusts, 258
H
Hair hygrometers, 267
Hartley–Huggins bands, 231
Heat flows, 29
Heat losses
black-and-white pyranometers, 128
black-disk thermopile pyranometers, 109
Heat transfer
conduction, 29
convection, 30
Heat transfer coefficient, 30
Helicoid propeller anemometers, 261–262
Hemispherical cup anemometer, 260
Henyey–Greenstein function, 230
Hickey–Frieden cavity radiometer, 67–69
Hooke, Robert, 36
determination of, 18
Hukseflux NR01, 222
Hukseflux pyrgeometer, 212–213
Hukseflux RA01, 220
I
Illuminance, 28
Incident diffuse radiation, 25
Incident flux, measurement of by photodiodes, 129
Incident infrared irradiance, determination of, 207–209
Incident solar radiation, 3–4, 8, 183 See also Extraterrestrial radiation
Indoor lamp calibrations, 244
Infrared irradiance, 26
measurement of, 3, 58–59 See also specific radiometers)
Infrared radiation (IR)
radiative loss, 110
spectral distribution of, 205–206
Infrared sky-scanning radiometer, 210–211
Infrared standard, 223
Infrasil II quartz domes, spectral transmission of light through, 116–117
Instantaneous irradiance, 23
Integrated Surface Irradiance Study (ISIS)
International Organization for Standardization (ISO), pyranometer classifications of, 107–108
International Pyrgeometer and Absolute Sky-scanning Radiometer Comparisons (IPASRCs), 211
International Pyrheliometric Comparison (IPC), 87
International Pyrheliometric Scale (IPS), 43, 47, 59
IPS. See International Pyrheliometric Scale Irradiance measurements, 22–23
deriving from satellites, 312–315
international reference scale for, 59–61
tilted, 3
Irradiance on a tilted surface, 298–302
Irradiance, Inc., rotating shadowband radiometer, 166, 171, 173
ISO. See International Organization for Standardization
Isotropic scatter, 230
J
JPL standard total-radiation absolute
radiometer, 59
K
Kelvin scale, 255
Kendall, J. M., Sr., 59
Kepler’s second law of planetary motion, 12
Kern rotating shadowband radiometer, 172, 173
Kipp & Zonen CG 4 model pyrgeometer, 207–208
calibration of, 210
operational considerations, 213–215
Kipp & Zonen CM model pyranometers
cosine response of, 118
linear response of, 115
temperature dependence of, 120–121
Kipp & Zonen CNR 4 net radiometer, 222
Kipp & Zonen model CNR 2, 220–221
Kipp & Zonen NR Lite2, 218–220
Kipp & Zonen solarimeter, 47–49
Kipp & Zonen SP Lite pyranometer, specifications of, 131–134
Kirchhoff’s law, 31
L
Laboratory calibration black bodies, 209–210
Lambert’s cosine law, 117
Laminar flow, 30
Lamp calibration, 244
Leap years, determining declination in, 11
Lensing effect of clouds, 23–24
LI-COR model LI-200SA pyranometer, 62–63, 80
Light detection and ranging (LIDAR) technology, 258
Line-by-line radiative transfer model (LBLRTM), 211–212
Local standard time (LST), 16–17, 278–279
Longwave radiation, 217
Luminosity function, 237
M
Marvin pyrheliometer, 47
Marvin, C. F., 47
Mean bias error (MBE), calculation of, 96–97
Measurement
artifacts in RSR data, 177–178
intervals for solar monitoring stations, 278–279
modeling and, 317
thermal offsets in pyranometers, 113–115
uncertainty analysis for calibration of cavity pyrheliometers, 88–90
uncertainty analysis for operational thermopile pyrheliometers, 90–91
Meteorological measurements, nonradiation, 4
Meteorological towers, 257–258
MFRSR. See Multifilter rating shadowband radiometer
Middleton CN1-R, 218
Models
estimation of solar irradiance using, 32–33
measurement and, 317
MODIS, estimations of albedo, 194
Molecular scattering, 229
Moll, W. J. H., 47
Moll–Gorczynski pyranometer, 48
Multifilter rating shadowband radiometer (MFRSR), 65–66, 179–181
use of to measure spectral albedo, 203
N
Narrow-band filter radiometry, 242–248
Narrowband photometry, 227
NASA
Ozone Monitoring Instrument (OMI), 231
Surface meteorology and Solar Energy (SSE) website, 96
National Centers for Environmental Prediction (NCEP), Global Forecast Systems (GFS) model, 194
National Oceanic and Atmospheric Administration. See NOAA
National Renewable Energy Laboratory (NREL). See NREL Nature of light, 35–36
standard, 223
Net radiometers accuracy of, 223
four-sensor, 222
sources for, 224
Newton’s law of cooling, 30
Newton, Sir Isaac, 35
NIP. See Normal incidence pyrheliometer
NOAA
Integrated Surface Irradiance Study (ISIS) network, 98–99
Surface Radiation (SURFRAD) network, 98–99
Nocturnal radiation, measurement of, 44
Nonlinearity, black-disk thermopile
Normal incidence pyrheliometer (NIP), 56–57, 116
NREL
Measurement & Instrumentation Data
Center online maintenance log, 283
pyrheliometer comparison, 88
Renewable Resource Data Center (RReDC), 13–14
Solar Radiation Research Laboratory data, 99
O
Operational instruments, recommended minimum accuracies for, 270
Operational radiometers, 44–67. See also specific radiometers
Operational thermopile pyrheliometers, 82–86
uncertainty analysis for, 90–91
Optical depth, 229
calculation of for ozone absorption, 231
Optical domes
effect of on angle of incidence response, 118–119
spectral transmission of light through, 116–117
Optical radiation measurement, 36–38
Orientation, 183.
∅rsted, Hans Christian, 109
Ozone absorption coefficients, 232–236
Ozone air mass, calculation of, 244
P
Pacific Northwest (United States) Solar
PACRAD. See Primary absolute cavity radiometer
Paint aging, pyranometer responsivity and, 119–120
PAR. See Photosynthetically active radiation Perihelion, 8, 12
Philipona, Rolf, 210
Photocurrent, 32
Photodiode-based pyranometers calibration, 141–142
effects of tilt on, 187
modeling PV system performance using, 189–191
reference solar cells, 142–143
use of in rotating shadowband radiometers, 171, 175
spectral response of, 131
temperature dependence of, 137–138
temperature response of, 131
Photoelectric effect, 28, 106–107
Photon scattering, 230
Photosynthetically active radiation (PAR)
use of to measure broadband albedo, 193–194
Photovoltaic devices
gas absorption and, 231
use of broadband filter radiometry to calculate efficiency of, 237
use of photodiode pyranometers in, 106–107
Photovoltaic panels, analysis of performance, 4
Photovoltaic reference cells, 131, 142–143
Photovoltaic systems, modeling performance of with photodiode pyranometers, 189–191
Physikalisch-Meteorologisches Observatorium Davos, 87. See also PMOD
Piezocapacitance barometers, 269–270
Piezoresistive barometers, 268–269
PIR. See Precision infrared radiometer Pitot tubes, 260
Pixel-to-cloud index conversion, 314
Planck’s law, 30
Plane of array (POA) solar irradiance, 78, 103
Plant stress, use of PAR albedos to predict, 194
Platinum resistance thermometer (PRT) detectors, 256
PMOD
Polar sun path charts, 321, 331–340
Pouillet, Claude Servais Mathias, 36
Precision infrared radiometer (PIR), 58–59
operational considerations, 213–215
Precision spectral pyranometer (PSP), 52–55
calibration plot of, 134
temperature dependence of, 120–121
thermal offset, 113
Prede, Inc. rotating shadow blade (RSB–100), 167, 172
Prediction Of Worldwide Energy Resource Project (POWER), 96
Primary absolute cavity radiometer (PACRAD), 59–61
Propeller anemometers, 261–263
Pryanometers, calibration of, 143–148
PSP. See Precision spectral pyranometer Pyranometer response, 167
Pyranometers, 36. see also specific pyranometers
Ångström, 47
black-and-white, 124–128, 186–187
black-disk thermopile, 108–124 See also
Black-disk thermopile pyranometers) calibration of, 112, 167–168
calibration uncertainties, 149–150
cleaning and maintenance of, 279–282
effect of tilt on accuracy of measurements, 188–189
fixed shadowband measurements of diffuse irradiance, 163–165
Kipp & Zonen models CM21 and CM22, 110–111
lack of Lambertian angular response of, 144
measurement of GHI using, 103–104
Moll–Gorczynski, 48
performance characteristics of, 108
photodiode-based, 128–143, 187–188
(See also Photodiode-based pyranometers)
precision spectral, 52–55, 110–111
Robitzsch bimetallic actinograph, 49–50
single black detector thermopile, 184–185
uncertainty analysis applied to the calibration of, 150–153
use of in rotating shadowband radiometers, 173–178
use of to measure albedo, 202–203
Pyrgeometers
Ångström Tulipan, 44
development of calibration standards for, 212
measurement of infrared radiation using, 206–209
modeling pyranometer thermal offsets using, 114
operational considerations, 213–215
Pyrheliometers. See also specific pyrheliometers Abbot silver-disk, 44–46
Ångström electrical compensation, 41–43
cleaning and maintenance of, 282
Marvin, 47
operational characteristics of, 82–86
space-based, 61
(See also Space-based measurements)
uncertainty analysis for calibration of cavity pyrheliometers, 88–90
uncertainty analysis for operational
thermopile pyrheliometers, 90–91
R
Radiant energy, 8
Radiation and Energy Balance Systems (REBS) Q–7. 1, 218–219
Radiative heat transfer, 30–31, 109
Radiometers, 4. See also specific radiometers
Abbot silver-disk pyrheliometer, 44–46
Ångström electrical compensation pyrheliometer, 41–43
Ångström pyranometer, 47
Ångström Tulipan pyrgeometer, 44
automatic Hickey–Frieden (AHF) cavity radiometer, 67–69
Campbell–Stokes sunshine recorder, 38–41
Eppley 180° pyrheliometer, 50–52
four-sensor net, 222
Kipp & Zonen solarimeter, 47–49
LI-COR model LI-200SA pyranometer, 62–63
Marvin pyrheliometer, 47
normal incidence pyrheliometer, 56–57
Pouillet’s pyrheliometer, 36, 39
precision spectral pyranometer (PSP), 52–55
primary absolute cavity, 59–61
Robitzsch bimetallic actinograph, 49–50
Smithsonian water-flow pyrheliometer, 46–47
World Standard Group, 67
Yanishevsky pyranometer, 53–55
Rayleigh atmosphere, optical depth of, 243
Rayleigh scattering, 161–162, 229
Record keeping, 283
Reda, Ibrahim, 212
Reference GHI, 118
Reflected global irradiance, 3
Reflected irradiance, 183
Reflectivity, spectral albedo and, 195
Relative humidity, 30
Resistive temperature detectors (RTDs), 256
Response degradation, black-disk thermopile pyranometers and, 119–120
Responsivity
calibration of pyranometers and, 151
solar zenith angle and, 153–156
summation calibration of pyranometers and, 146–148
calculation of, 16
Robinson, John Thomas Romney, 260
Robitzsch bimetallic actinograph, 49–50
Robitzsch, Max, 49
Root mean square errors (RMSEs), calculation of, 96–97
Rotating shadowband pyranometer (RSP), 64, 80
use of for measuring diffuse irradiance, 166–167
Rotating shadowband radiometer (RSR), 3, 64
uncertainty analysis for measurements of DNI, 93–94
Rotating shadowband sun radiometers, 247
RSP. See Rotating shadowband pyranometer
RSR. See Rotating shadowband radiometer
S
Sampling frequency
multifilter rating shadowband radiometer, 179
rotating shadowband radiometers, 175–177
Santa Barbara DISORT Atmospheric Radiative Transfer (SBDART) model, 249–250
Satellite irradiance models, 315–317
Satellite model estimates of DNI, 95–97
Satellites. See also Space-based measurements
deriving irradiance measurements from, 312–315
use of to site solar plant installations, 79–80
Rayleigh, 229
Schenk 8111 pyrradiometer, 220–221
Schenk Star pyranometer
tilt effects on, 186
Schott WG295 glass, spectral transmission of light through, 117
Schulze-Däke net radiometer, 220
Scotopic response, 237
Sea salt aerosols, 230
Self-calibrating absolute cavity radiometers (ACRs), 83
Semiconductors, 32
Sensitivity coefficients, 150
use of in calibration of pyranometers, 151–153
Sensors, tilted, 3
Shade disk vs. calculated diffuse irradiance, 165–166
Shade–unshade calibration technique, 141, 144–146, 167–168
Shielding, 276
Shortwave radiation, 217
Shut resistance current, 32
Sidereal day, 12
Silicon cell radiometers, 4. See also Radiometers
Silver-disk pyrheliometer, 46
Simple Model of the Atmospheric Radiative Transfer of Sunshine (SMARTS) model, 249
Single black-disk thermopile pyranometers. See Black-disk thermopile pyranometers
Single scattering albedo, 230
Single-sensor net radiometers, 218–220
Sky irradiance, 103
Sky scanner, calibration of, 210–211
Sky temperature, effective, 110
Slab, heat transfer across, 29
Sling psychrometers, 267
Smithsonian 1913
Scale of Radiation, 43, 46, 59
Smithsonian water-flow pyrheliometer, 46–47
Snell, Willebord, 36
Snow-covered surfaces, spectral albedo of, 198–199
Soil, spectral albedo of, 198–199
Solar analemma, 14
external quantum efficiency of, 129
spectral response of, 130
temperature coefficient of, 137–138
Solar constant, 8, 36. See also Total solar irradiance
Solar day, 12
Solar flat plate collectors. See Flat plate solar collectors
Solar hour angle, 11–12. See also Hour angle
Solar irradiance
estimation of values of, 32–33
ground-based modeling of, 95
satellite model estimates of, 95–97
Solar irradiation monitor (SIM), 228
Solar measurements
nineteenth century radiometers, 36–44
operational radiometers of the twentieth century, 44–67
Solar Millennium AG, rotating shadowband radiometer, 166–167, 171, 173
Solar monitoring stations, 4
cleaning and maintenance, 279–283
data loggers and communications, 276–278
grounding and shielding, 276
measurement intervals, 278–279
record keeping, 283
sun path charts and siting of, 19–20
Solar noon, 12
Solar plant installations, siting, 79–80
Solar position, calculation of, 17–20
Solar position algorithm. See spa.c Solar position algorithms, 341–343
Solar radiation
atmospheric interactions, 229–237
data, 27
estimates derived from satellite measurements, 311–317
international reference scale for measurement of, 59–61
spectral distribution of, 227, 249–250
SOlar Radiation Climate Experiment (SORCE) satellite, 69, 77
measurement of spectral irradiance, 228
Solar reference cells, 142–143
Solar resource assessment, 1–2
Solar spectrum, extraterrestrial, 227–228
Solar time, 16
Solar zenith angle, 8, 200. See also Zenith angle
dependence of spectral albedo on, 195–196
determining the average cosine of, 304–305
effect of on surface albedo, 194
uncertainty due to dependence of, 92–93
Solarimeters, Kipp & Zonen, 47–49
Sonic anemometers, 263
SORCE satellite. See SOlar Radiation Climate Experiment satellite
Sound detection and ranging (SODAR) technology, 258
Space-based measurements
total irradiance monitor, 69–70
total solar irradiation, 77
measurement of, 203
Spectral corrections for MFRSR, 179
Spectral distribution solar radiation, 227
sunlight, 35
Spectral irradiance black body, 205–206
conversion of into illuminance, 237
Spectral measurements, 4
Spectral nature of solar radiation, 25–28
Spectral response
black-disk thermopile pyranometers and, 116–117
photodiode-based pyranometers, 138–139
photodiodes, 131
use of rotating shadowband radiometers to measure, 65
Standard uncertainty, 152
derivation of, 89
estimating for operational pyrheliometers, 91
rotating shadowband radiometer, 94
Star-type pyranometers, 106
Stefan, Jožef, 30
Stefan–Boltzmann law, 30
Stokes, Sir G. G., 40
Strain gages, 268
Subtraction method, diffuse values obtained from, 163–166
Summation calibration technique, 141, 146–148
accurate DHI measurements for, 169
Sun
Sun dial plot, 22
Sun path charts, 18–19, 274–275
Sun–earth distance, 8
Sunrise, calculation of time of, 20–21
Sunset, calculation of time of, 20–21
Sunspots, 35
estimations of, 194
Surface radiation, wavelength dependence of, 195
Surface Radiation (SURFRAD) network, 98–99, 217, 292
broadband albedo measurement, 202
Surface solar irradiance, satellite estimates of, 95–97
Surface-measured DNI data, 97–100
Systematic errors, rotating shadowband radiometers, 175–177
T
Temperature, 255
types of sensors for measuring, 256
Temperature response
black-and-white pyranometers, 127
black-disk thermopile pyranometers and, 120–121
photodiodes, 131
use of rotating shadowband radiometers to measure, 65
Temperature sensitivity, uncertainty due to, 91–92
black-disk thermopile pyranometers, 113–115
correcting for diffuse measurements, 168
lack of in black-and-white pyranometers, 128
tilted measurements and, 184–185
Thermistor resistance, 214–215
Thermistors, 256
Thermodynamics, fundamentals of, 28–31
Thermoelectric effect, 28, 106, 109
Thermometers, 256
Thermopile pyranometers
black-disk, 108–124 See also (Black-disk thermopile pyranometers)
optical domes for, 108
use of in rotating shadowband radiometers, 175
Thermopile pyrheliometers
operational characteristics, 82–86
uncertainty analysis for, 90–91
window transmittance and temperature sensitivity of, 91–92
Thermopile radiometers, 4, 28. See also Radiometers
constantan, 106
Thermopile shadowband radiometer (TSR), 65
Tilt, 183
effect of on black-and-white pyranometers, 186–187
effect of on photodiode pyranometers, 187
effect of on single black detector pyranometers, 184–185
Tilted irradiance measurements, accuracy of, 187–188
Tilted pyranometers, use of in rotating shadowband radiometers, 175
Tilted surfaces
approximating global tilted irradiance for, 183
measurement of solar irradiance on, 3
modeling irradiance on, 298–302
solar radiation on, 25
TIM. See Total irradiance monitor Time response, 258–259
Torticelli, Evangelista, 268
Total irradiance monitor (TIM), 69–70
measurement of spectral irradiance by, 228
Total solar irradiance (TSI), 8, 77
measurement of, 36
space-based measurement of, 69–70
Total solar radiation on a tilted surface. See Plane of array (POA) solar irradiance
Total solar spectrum albedo, 193
Transmission of the atmosphere, 236–237
Triple point, 255
True angular response, 117–119
TSI. See Total solar irradiance
TSR. See Thermopile shadowband radiometer
Turbulent flow, 30
Two-sensor net radiometers, 220–221
pyranometer calibration and, 153–156
pyranometer calibration and, 150–153
U
U.S. Department of Energy (DOE), Atmospheric Radiation Measurement (ARM), 99–100
Ultraviolet (UV) radiation, 26
broadband radiometric sensors, 241–242
Uncertainty analysis
application of to pyranometer calibration, 150–153
calibration of absolute cavity pyrheliometers, 88–90
operational thermopile pyrheliometers, 90–91
pyrgeometers, 215
rotating shadowband radiometer
Universal time (UT), 17
University of Oregon Solar Radiation
Monitoring Laboratory (UO SRML), 98, 291–293
Upwelling infrared radiation, 217
V
Variability of solar irradiance and gravity oscillations (VIRGO) radiometer, 69
Variable conditions pyrheliometer comparison (VCPC), 84–86
Vegetation, spectral albedo and, 195–198
Ventilators
black-disk thermopile pyranometers, 121–122
pyrgeometers, 213
VIRGO radiometer. See Variability of solar irradiance and gravity oscillations radiometer
Volcanic eruptions, aerosol scattering due to, 229–230
W
Water vapor, use of narrow-band filter radiometers to measure, 245–247
Water vapor absorption, 231
Wavelength dependence, 95
spectral albedo and, 203
Websites 3TIER, 96
Baseline Surface Radiation Network (BSRN), 98
NASA Ozone Monitoring Instrument, 231
NOAA Integrated Surface Irradiance Study (ISIS), 99
NREL Measurement & Instrumentation Data Center, 283
Prede Co. Ltd. of Japan, 172
Prediction Of Worldwide Energy Resource Project (POWER), 96
Renewable Resource Data Center (RReDC), 13–14
SBDART model, 250
SMARTS model, 249
Solar Anywhere service of Clean Power Research, 96
solar inventory, 79
Solar Millennium AG, 172
solar position algorithm, 14
SOlar Radiation Climate Experiment (SORCE) satellite, 77
Sun Chart Program, 274
sun path charts, 19
Surface Radiation (SURFRAD) network, 217
SURFRAD, 99
UDT photometry, 239
WISG pyrgeometer infrared standard, 212
World Infrared Standard Group, 223
World Radiation Data Center, 41
Wheatstone bridge, 269
White-sky albedo, 200
Wien’s law, 31
Wind measurements
speed and direction, 258
Window transmittance, uncertainty due to, 91
WMO. See World Meteorological Organization Wolf, Rudolf, 35
World Climate Research Program, Baseline Surface Radiation Network (BSRN), 97–98
World Infrared Standard Group (WISG), 212, 223
World Meteorological Organization (WMO)
CIMO guide to meteorological measurements, 255
pyranometer classifications of, 107–108
World Radiation Data Center, 98
World Radiometric Reference (WRR), 61, 67, 87
uncertainty of, 89
World Standard Group (WSG), 87
World Standard Group radiometer, 67
WRR. See World Radiometric Reference
WSG. See World Standard Group
Wulf bands, 231
Y
Yanishevsky pyranometer, 53–55
Yankee Environmental Systems (YES), Inc. radiometers, 167, 171, 178–181
use of to measure spectral albedo, 203
Z
determination of, 18