The D-Region Absorption Prediction (D-RAP) Model, produced by the Space Weather Prediction Center (SWPC), provides real-time graphic and text information about global High Frequency (HF) radio propagation conditions related to the ionosphere's D-region. The D-RAP model became an official NWS/SWPC product on November 18, 2009. NCEI archives and provides access to the D-RAP model outputs from Sep 2009 until the present.
D-RAP Data and Plots
D-RAP Animations and Documentation
- D-RAP Documentation (by SWPC)
- D-RAP readme (by NCEI)
- D-RAP2 Product Description Document (PDD)
- D-RAP Validation Report (2010)
- D-RAP Event Animations (Solar X-ray class flare indicated):
- 2000/07/14 (X5.7 flare)
- 2001/04/02 (X22 flare)
- 2001/04/06 (X5.6 flare)
- 2002/10/05 (M5.9 flare)
- 2002/10/31 (X1.2 flare)
- 2002/11/18 (M7.4 flare)
- 2002/12/20 (M6.8 flare)
- 2003/01/07 (M4.9 flare)
- 2003/10/28 (X17 flare)
- 2003/10/29 (X10 flare)
- 2003/11/04 (X28 flare)
- 2006/07/16 (X3 flare)
Product Details
The D-Region of the ionosphere is important to the propagation of HF radio signals. The lowest available frequency for HF users is directly related to the electron density in the D-Region. Due to space weather effects, the electron density can vary dramatically over time scales as short as a few minutes. The D-RAP Model uses empirically determined relationships to compute HF absorption and the highest affected HF frequencies directly from space weather input parameters.
The Global D-region Absorption Prediction Documentation, the Space Weather Journal article: Sauer and Wilkinson (2008), and the D-RAP Model Validation report (2010) provide additional information pertaining to the operational D-RAP product, the Ionospheric D-Region, and the impacts of X-ray and Proton flux on HF communication.
Please visit SWPC Real-Time D-RAP webpage for more information on the D-RAP product inputs/outputs or to submit your questions and comments about this model.
