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Re: (meteorobs) Distance for simultaneous meteor observation
> I have noticed this question come up several times
> before, so here is the precise answer to this query:<
>
> How about someone writing a meteorobs FAQ with all
> this useful information in !
>
> Any volunteers !
Definitions :
s = distance [km] ALONG the earth surface from where
the meteor is at zenith (the "zenith location").
h = height [km] of the meteor (typical 80-120 km) at the
"zenith location".
r = earth radius (approx 6378 km)
A(rad) = Angel [radians] above the horizon at which you see
the meteor at s km away from the "zenith location".
A(deg) = Same as A(rad), but in degrees (360 deg = full circle)
Calculations :
h cos(B) - (r - r cos(B))
A(rad) = arctan ---------------------------------------
r sin(B) + h sin(B)
where B = s / r
A(deg) = A(rad) * 260 / (2 Pi) ; Pi = 3.141592
Examples :
Meteor height = h = 80 km :
In the horizon at s = 1000 km,
30 deg above the horizon at s = 135 km
45 deg above the horizon at s = 80 km
Meteor height = h = 100 km :
In the horizon at s = 1120 km,
30 deg above the horizon at s = 166 km
45 deg above the horizon at s = 97 km
Meteor height = h = 120 km :
In the horizon at s = 1225 km,
30 deg above the horizon at s = 200 km
45 deg above the horizon at s = 116 km
I can send you an Excel program that calculates A as a function of s for a given
h.
Regards,
Birger Andresen, Norway.
birger.andresen@fesil.no
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