Kippzonen BSRN Scientific Solar Monitoring System Manual do Utilizador descarregar pdf (Página 10)

VIII

List of Figures

Figure 1.1. Map of BSRN sites..............................................................1

Figure 3.1. Diagram indicating appropriate distances from an obstruction meteorological instrumentation

(from AES Guidlines for Co-operative Climatological Autostations, Version 2.0). . . . . . . 25

Figure 3.2. Simple post mount in concrete base ..............................................26

Figure 3.3. The support structure used to elevate instruments above the local horizon . . . . . . . . . . . . . . . 27

Figure 3.4 Generalized schematic of the interface between radiation sensors (RF) and a data acquisition

unit showing lightning protection and cable grounding. . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Figure 4.1. Ventilator with motor located beside the instrument as used by Deutscher Wetterdienst. . . . . 32

Figure 4.2. Ventilator with the motor located beneath the instrument. Note the extra ventilation holes

near the top of the housing used to reduce snow accumulation (Davos, Switzerland).

.......................................................................33

Figure 4.3. An one-axis tracker used in shading a pyranometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Figure 4.4. View of two Swiss oversize tracking disks. Note how the pyranometer is physically separated

from the motor and the shade device. ........................................34

Figure 4.5. Australian active tracker used for both diffuse and direct beam measurements . . . . . . . . . . . 36

Figure 4.6. Canadian computer-controlled, friction-drive tracker used for measuring direct beam, diffuse

and infrared radiation using a shaded pyrgeom eter. The pyrheliometer mounting block is

capable of holding three instruments, including an active cavity radiometer. A second

mounting place is mounted on the opposite side of the tracker. . . . . . . . . . . . . . . . . . . . . 38

Figure 4.7. The contribution of the solar disk to the irradiance of pyrheliometric sensors depending on the

pointing error. (A) Case of mountain aerosol and 60° solar elevation. (B) Case of

continental aerosol and a 20° solar elevation. (Calculations and graph courtesy of G.

Major) ..................................................................41

Figure 4.9. Brusag two-axis active tracker ...................................................41

Figure 4.8. A single-axis synchronous motor tracker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Figure 8.1. Percentage change in infrared flux due to case thermistor errors . . . . . . . . . . . . . . . . . . . . . . . 69

Figure C 2.1. Penambra functions of diffusometers for 45 degrees solar elevation. . . . . . . . . . . . . . . . . . 117

Figure C 2.2. Compared log measured and calculated circumsolar functions. Letters A, B, C, D, E, F

symbolizes different aerosol models. ........................................119

Figure C 2.3. Measured sky functions and their approximations by ones calculated for model atmosphere

containing rural aerosol and haze particles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

Figure C 2.5. Dependence of the HUNI/HUNIII on direct radiation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

Figure C 4.1. Measured sky functions and their approximations by ones calculated for model atmosphere

containing rural aerosol and haze particles too (courtesy of Major, 2001). . . . . . . . . . . 129

Figure C 4.2. Relationship between the geometry of pyrheliom eters and radiance (The relationship

applies for a diffusometer when the sun is at zenith). . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

Figure C 4.3a. Relationship between the shadow disc and the sensor of a pyranometer. . . . . . . . . . . . . 131

Figure C 4.3b. Detail of the sensor projection on to the normal plane parallel to the shadow disc. . . . . . 131

1 2 ... 5 6 7 8 9 10 11 12 13 14 15 ... 187 188

Sem comentários

Kippzonen BSRN Scientific Solar Monitoring System Manual do Utilizador Página 10