The magnetic loop antennae are used to find the direction of the strike. The outcome however is ambiguous with respect to 0/180 degrees. You then use the electric field (sense) antenna to disambiguate the 0/180 degree solutions.
At least that’s how it’s done in the ADF (and I thought all brits were experts about ADF 8-)), see this AvWeb
article.
I would expect this to be done the same way in a storm scope. So you need the E field (in addition to the H field) to get an unambiguous direction.
Inaccuracy of the Stormscope with respect to distance estimate is a non issue IMHO. The later design units do a better job, but even the old Ryan 7 did what it needed to accomplish. It kept me out of thunderstorms. I have become quite adept at interpreting the radial spread and using it along with the rate of strikes being displayed to gage where it is and how intense. It is just a strategic planning tool and is not useful for tactical picking your way thru a line of thunderstorms. I also have satellite delivered lightning information based on ground sensors that are much more accurate and at the same time less useful as they are sparse and delayed several minutes. I use the Stormscope for what it was intended to be used for.
I have very good navigation equipment and Satellite NEXRAD weather, but if the Stormscope says I will have a good flight on my current path, that is what happens.
