From: Ivan Marti-V. <i.m...@go...> - 2012-05-16 15:04:08
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Dear all, I've been working on a "observability" plugin, which is almost complete. One of the main issues I had was the estimate of the opposition date and the range of good night-time observation dates for the planets, since I needed to access the planets ephemeris. I solved this issue by doing: PlanetP planet = The shared pointer of interest Planet* ppoint = planet.data(); Then, I could generate the ephemeris easily by calling to the function "computePosition" and "getHeliocentricPosition" for both the planet and the Earth (taking also into account the transformation matrix from Heliocentric to Earth, and from J2000 to current equinox). Obviously, I return the planets to the current simulation date just after obtaining the desired data, so everything is completely transparent to the sky rendering. Also, this is done only once per object selection, so the approach is quiete efficient computationally. The problem I have now is that this approach is not good for the Moon. I want to compute the rise/set/transit times for the Moon at the current simulation day, so I also need to get the Moon's ephemeris to solve the problem numerically. I've tried to run "getEclipticPos", but the rotation matrix to the parent (i.e., the Earth) is protected. I also tried to compute the matrix myself, but the orbital elements are also protected. Do you have an idea of how to proceed? I'd be very thankful! Best Wishes, Ivan |