DW sound propagation model measurements

Dr.Sid · 08-18-07, 10:56 AM

I updated the first post with new convergence zones measurements. Nothing unexpected was found, but the data now are more complete. I've updated both image and text.

In short I can say that CZ are about the same as surface duct. Except:

1) layer is more shallow, shadow zone starts closer.
2) there are the convergence zones, exactly at 30 and 60 nm. That one on 30 nm makes signal stronger from 18 to 39 SNR. That on 60 nm cannot bring the signal above 0 SNR, but on NB display it can change practically invisible line into 2 quite strong lines.

Convergence zones both are pretty narrow, you can cross them in seconds (depending on speed difference) so they are easy to miss.

08-18-07, 10:56 AM	#20
Dr.Sid The Old Man Join Date: May 2005 Location: Czech Republic Posts: 1,458 Downloads: 6 Uploads: 0	I updated the first post with new convergence zones measurements. Nothing unexpected was found, but the data now are more complete. I've updated both image and text. In short I can say that CZ are about the same as surface duct. Except: 1) layer is more shallow, shadow zone starts closer. 2) there are the convergence zones, exactly at 30 and 60 nm. That one on 30 nm makes signal stronger from 18 to 39 SNR. That on 60 nm cannot bring the signal above 0 SNR, but on NB display it can change practically invisible line into 2 quite strong lines. Convergence zones both are pretty narrow, you can cross them in seconds (depending on speed difference) so they are easy to miss.