Discrepancy in the CCIR Report 322-3 Radio Noise Model. The Probable Cause and aRecommended Solution

摘要

The cause of a reported discrepancy in the CCIR Report 322-3 radio noise modelwas determined, and a course of action to overcome the discrepancy is recommended. The source of the discrepancy was found to be in the procedure used to prepare the measured noise data for the determination of a global numerical representation of the 1-MHz data. In the development of the model, correction factors to the old CCIR model were determined for each measurement site. These corrections were interpolated to a 100-latitude by 84-longitude grid for each time block/season. The correction factors at each grid point were then added to corresponding values for the old CCIR model, and finally the resulting data for each time block and season were numerically mapped. Nineteen locations were used in the final model. Four sites used in the original CCIR model were not used, including Bill, Wyoming; Byrd Station, Antarctica; Ibadan, Nigeria; and Thule, Greenland. As no correction factors were obtained for these locations or a correction factor of zero used, the interpolation algorithm used to obtain the 100-latitude by 84-longitude grid of correction factors supplied other values. For Bill, Wyoming, the result is not too serious; but for the other three sites, the error is at some seasons and time of day serious. For Thule, Greenland, the maximum and minimum errors in the correction contours were 10. 1 and -10.8 dB, respectively. For Ibadan, Nigeria, the maximum and minimum errors were 12.5 and -1.5 dB, respectively. For Byrd Station, Antarctica, the maximum and minimum errors were 12.0 and 3.0 dB, respectively.