Simulated Weather Imagery (SWIm) | Purpose | Gallery | Cases

Visually and physically realistic sky (and land) simulations are being produced from real-time weather data. For example a 3-D cloud/aerosol analysis (from the updated Local Analysis and Prediction System - LAPS), running over a Colorado 500 meter resolution domain uses satellite (including IR and 500m or 1km resolution visible imagery, updated every 5-15 minutes), METARs, radar, aircraft and model first guess information to produce 3-D fields of cloud fraction, cloud liquid, cloud ice, rain and snow. The 500m grid resolution takes advantage of the 500m satellite resolution in the visible wavelengths. The LAPS system produces rapid update, high resolution analyses and forecasts of clouds, precipitation, and land surface information. The gridded fields are then converted using a ray-tracing technique into an all-sky image. Here are more details in this satellite data workshop (JCSDA) presentation. A 2014 ESRL news story on this work has been posted. Overall, visualizations are being tested with analyses of present weather from LAPS & GSI along with forecasts from LAPS, FIM, CSU/RAMS, NAVGEM, and HRRR. Preliminary camera assimilation work is being done with the GSI analysis. Other variational assimilation (4DVAR), directly using visible and IR radiance information (e.g. at a 1-minute cadence) from cameras and satellites in a tomographic fashion is being proposed for use in various systems.

Aeronet Validation

Thanks to Janae Csavina from NEON/Battelle in Longmont for the Aeronet radiance observations.

The above image comes directly from the camera, about 30 minutes more recent than the comparisons below.

The image above on the left is simulated from the LAPS cloud/aerosol analysis and other data, while the image on the right is from a webcam located at RadioMetrics (just NE of Boulder, CO) at the same time. In each fisheye lens view the zenith is in the center and north is up. The color balance of the simulated image is set to reproduce the "actual" colors/radiances when the display white point is set to closely match the sun. Thus to see a true apples to apples comparison (if for example you take your computer outside or right by a window), please set your display to a color temperature of 5780K (the sun's white color above the atmosphere). Some images are shown a bit dark to avoid saturating and losing details on the bright end. This can be compensated for by turning up your monitor brightness, thus showing a broader dynamic range.

Select Site — DSRC | NREL | CIRA | RadioMetrics | BAO Tower | Pikes Peak | Mount Evans

Latest all-sky comparison image | mask (site is RadioMetrics)

Latest comparison animations (site is RadioMetrics): Polar | Cylindrical

In these 360 degree panoramic (all-sky) views, a simulated LAPS image is shown (top) compared with a remapped camera image (middle) from an all-sky camera maintained by RadioMetrics. South is at the center of each image and north is at the edges. The listed solar irradiance is calculated from the same radiance information used to construct the image.

Latest Camera | (Moore Tornado)

Archive Directories (site is RadioMetrics): Polar Comparison | Polar Blinking | Cylindrical Comparison | Polar Camera | Cylindrical Camera | Raw Camera

Other Related Endeavors from around the web

More visualizations are on my main home page | Contact: Steve Albers (Steven.Albers@colostate.edu)