RGB Experts and Developers Workshop - Introduction Tokyo, Japan 7-9 Nov 2017

Transcription

1 RGB Experts and Developers Workshop - Introduction Tokyo, Japan 7-9 Nov 2017

2 Workshop Objectives Review of existing RGB standards Reconfirm and extend existing standards (new multi-spectral imagers) Stimulate creation of suitable RGB demonstration and training material, especially for Asia/Pacific region and Western Indian Ocean Standardization of other composites and enhancements, e.g. sandwich product, single channel enhancements Usage beyond nowcasting applications

3 Previous RGB Workshops 2007 in Boulder, CO, USA, organzed by WMO 2010 in Seeheim, Germany, jointly organized by EUMETSAT and WMO Workshop reports available at

4 2007 Workshop Recommendations Guidance tables to associate each of the red/green/blue components with a meteorological or physical parameter Two groups of RGBs identified: Focus on atmospheric attributes (lead with EUMETSAT) Focus on surfce attributes (lead with COMET/UCAR/CIRA)

5 Guidance Example Airmass RGB (clear sky) Red: 6.2 µm 7.3 µm difference height of moisture layer (mid level, high level) Green: 9.7 µm 10.8 µm ozone content Blue:6.2 µm (inverted) air mass type

6 Examples of the Two RGB Groups Airmass, Fog, Cloud Microphysics, Dust,. Natural Colour, Snow/Sea Ice, Wildfires,

7 2012 Workshop Recommendations (1 of 2) Usefulness of standard RGBs is confirmed Channel rules are reiterated Combined use of RGBs and derived products is encouraged Advances in derived products are recognized, RGBs have additional value in difficult conditions, e.g. twilight RGBs based on IR channels seen as most robust for forecasting Need for consistent naming convention seen (e.g. natural colour) Continued availability of relevant imaging channels on future missions, both GEO and LEO Focus on validation of RGBs and derived products needed

8 2012 Workshop Recommendations 2 of 2) Digitization of satellite signals should be at least 10 bit Ambiguity of convective storm RGB is recognized RGB colour interpretation should be associated with features Importance of training is stressed Forecaster bench display should retain full resolution Emerging RGBs should be discussed in the community Literature review of RGB applications should be done Satellite providers should make full resolution real time images available for evaluation and training (pending data policy)

9 Example: RGBs and Derived Products BT difference µm, Showing dry and moist air masses Total Precipitable Water product This example shows a slight advantage of the derived product, as it better accounts for effects like surface emissivity

10 Example: Ambiguity of Convection RGB This example shows that the RGB allows a skilled forecaster to better identify ash, especially in confusing scenes like underlying cloud layers Crown copyright Met Office (source: P. Francis) Ash RGB Derived product: ash detection

11 Example: Ambiguity of Convection RGB The bright yellow colour in this RGB can be either due to - Small ice crystals at cloud top level (i.e. strong updraft, very active part of the cloud) - Very cold cloud top temperature and larger ice particles

12 New Challenges for this Workshop New multi-spectral imagers in GEO orbit: ABI / AHI, and more to come in the near future: RGBs mainly based on MSG SEVIRI heritage modifications necessary due to spectral reponse differences? New RGBs based on new channels, e.g. 0.47µm, 0.85µm, 1.375µm (only ABI), 2.2µm New multi-spectral imagers in LEO orbit: VIIRS, METImage (future)

13 New Challenges for this Workshop New geographic regions covered: Asia / Pacific, Meteosat-8 over the Indian Ocean Future pseudo-rapid scans possible over Asia/Pacific region (Himawari, GEO-KOMPSAT, FY-4A) impact on RGBs

14 New Challenges for this Workshop Other channel composites, e.g. temperature difference images, sandwich products, standardization of single channel colour enhancements Combined use of RGBs and derived products, NWP output and conceptual models Creation of suitable demonstration and training material