1 / 2

Sun and Aureole Measurements A Sensor for Cloud Optical Properties and Circumsolar Radiation

10. Lab calibration - NIST traceable (see Visidyne Cal Brochure VI-5487) Radiometric accuracy: Disk radiance <1% for OD <0.6, 3% for OD 2 (DNI ~ 250 w/m 2 ) Aureole radiance ~5% - 15% Aureole profile precision: Pixel-to-Pixel Std Dev ~0.5%

kylee
Download Presentation

Sun and Aureole Measurements A Sensor for Cloud Optical Properties and Circumsolar Radiation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 10.Lab calibration - NIST traceable • (see Visidyne Cal Brochure VI-5487) • Radiometric accuracy: • Disk radiance <1% for OD <0.6, 3% for OD 2 (DNI ~ 250 w/m2) • Aureole radiance ~5% - 15% • Aureole profile precision: • Pixel-to-Pixel Std Dev ~0.5% • For ODs <~2 there is a data gap of • ~ 0.1o (~0.3 to 0.4+ degrees) due • to the aureolegraph design, typically • <1% error in CSR • 9. SAM 300 Series Sensors • Dome versions (very robust) have produced data daily at the Goddard Space Flight Center (MD) and at the DOE/ARM CRF (OK) under a NASA grant and with DOE/ARM support Sun and Aureole Measurements A Sensor for Cloud Optical Properties and Circumsolar Radiation Example Web Display (Daily) www.visidyne.com/sam/sam_data.htm • 11. Field Calibration/Verification • Absolute radiometric calibration of solar disk camera; verified with thousands of measurements made next to AERONET • Consistent aureole pixel-to-pixel response, e.g. “gradient” correction; verified with hundreds of measurements of uniform clouds • Stable for long periods • ~ 24 months at NASA GSFC (MD) • ~ 12 months at DOE/ARM CRF (OK) Contacts A.T. Stair 781-272-1220 ats@visidyne.com John DeVore 781-791-3209 devore@visidyne.com Upper: SAM OD & AERONET Middle: Disk & Aureole Radiance, Integrate for CSR Lower: Derived particle size distribution (see J. Atmos. Ocean. Tech., 26, pg 2531) VI-5493a April, 2012

  2. 1.Weatherized SAM 400 Series • 3. SAM is a patented, calibrated, integrated sensor suite with dedicated software: • Precision solar tracker • Solar disk camera • Aureolegraph imager • Spectrometer-vis/nir (optional) • Halo camera (optional) • 4. Capabilities - 5 Years in Development and Applications • Uses a narrow-band filter at 670 +/-5 nm (changeable) and measures: • --Solar disk radiance (OD) • ODs from 0.01 to 10 • --Aureole (circumsolar radiation) • from near edge of solar disk to 8o • from center (see item 10) • --Atmospheric constituents • (see item 7) • --Aureole (halos)-vertical to 50º • 5. Papers and Posters • Particle size distributions: ~5 • to ~65 mm (400 Series); see DeVore, • et al., “Retrieving Properties of Thin Clouds From Solar Aureole Measurements”, JAOT, 26, pgs 2531 • - 2548. • Posters from science meetings and all papers are available at: www.visidyne.com/SAM/Papers.htm 6. Direct Normal Irradiance 7. SAM Spectrometer Data Sensor (20 x 60 cm); Control console not shown (30 x 48 x 74 cm) 2. Data Example (OD ~2) Ozone Aerosols • 8. DNI From SAM Data • 1) Use measurements: • Spectral irradiance (item 6) • H2O, O3 & aerosols (item 7) • 2) Convert to broadband irradiance • Use radiative transport model,or • regression analysis from DNI • 3) Integrate over wavelength Aureolograph Image

More Related