Originally Posted by
Mason32
With some skillful use of the gain, you should be able to actually determine storm levels accurately. You can use the National Weather Service scales as a reference. For example. The Honeywell Primus in the EMB has a base DB of 20 decibells. For ANYTHING to show up at all, it has to return at least 20 DB's. Each tick mark on the gain control is 3 DB's. Adjust the gain control from full, down until your target just disapears. Count the number of tick marks on the gain control, multiply times 3 and add the baseline of 20 DB's. That will give you the actual DB return of the cell/area in question. Use the number of DB's as compared to the NWS scale and you now know what level storm you are looking at. Re-adjust the gain knob to display the appropriate colors.
Hope this helps.
I have never flow any of the RJ's but in every type of radar i've used the gain knob was used primarily for ground mapping. In fact in many of the radars i've used the gain knob was only functional in the ground mapping mode. In other radars you had to select a varible gain swith to activate the gain knob. This is so that in normal weather mode the colors will correctly depict the level of returns.
My understanding, and correct me if I am wrong, but a radar is callibrated to show level 1 as green, level 2 yellow, 3-4 red, 5-6 magenta.
With all this in mind why would you have to play with the gain knob to determine the level of the weather?