Combination of Radio Noise modification
Noise is combined in the VOACAP and ICEPAC HF propagation models using
An Updated Noise Model for use in IONCAP,
NTIA Report 87-212, January 1987.
Spaulding, A. D. and Stewart, F. G.
It has recently (fall 2006) been discovered that under certain conditions of frequency,
season, time, location, and man-made noise that this model can produce some undesireable results.
A collaboration between myself and John Caruana of Australia has produced a modification
of this model. I will refer to this as the modified Spaulding method.
A joint ITU submission (US & Australia) has been created and is being presented at
the April 2007 ITU meetings in Geneva as a modification to Recommendation ITU-R P.372-8
Combination of Radio Noise. This recommendation is the successor to the old
CCIR Report 322-3, "Characteristics and Applications of Atmospheric Radio Noise Data".
As of 4/13/2007, The HF models VOACAP and ICEPAC available from my site:
High Frequency Propagation Models - ICEPAC, VOACAP, REC533
have been updated with this modified Spaulding method.
Significant changes to REC533 are expected to be done after the April 2007 meetings.
I have also developed a program that calculates results of combining radio noise from
the three sources (Atmospheric, Galactic, Man-Made) that affect HF communication.
The outputs of this program are both single location calculations and contours
of any of the noise parameters plotted on a world map.
These contour maps can be used to reproduce the Fam 1 MHz maps found in ITU-R P.372-8.
Files you can download are:
itu_submission.doc - document describing the ITU submission.
gh_noise.zip - contains the noise calculation program.
readme.txt - instructions on installing the program.
help.txt - detailed description of the noise program.
noise1.jpg - sample contour map.
I will update this website after the April 2007 ITU meetings are completed to detail
any additional information concerning this topic.