irfpy.cy1orb.pvat

pvat module is a collection of functions (syntax sugar) for the PVAT related calculations.

  • Orbit of CY-1 for arbitrary time by getorbit()

  • Conversion from SC frame to LSE for arbitrary time frame by getlsevec()

Note

Use irfpy.cy1orb.pvat2 for practical use.

irfpy.cy1orb.pvat2 aims to replace of irfpy.cy1orb.pvat, because the first implementation of irfpy.cy1orb.pvat has a problem in its specification on caching. Clearly stating, irfpy.cy1orb.pvat uses huge memory after a long use. Now irfpy.cy1orb.pvat2 uses irfpy.util.ringcache to solve the problem.

However, performance in the calculation time is slightly worse than pvat. The calculation of irfpy.cy1orb.pvat2 takes 10% more time than irfpy.cy1orb.pvat.

irfpy.cy1orb.pvat.clear_cache()[source]

Clear cache related to pvat module.

irfpy.cy1orb.pvat.getlsepos(t)[source]

Get LSE orbit at the time of t as an instance of Vector3d.

The LSE orbit in km unit is returned. The returned position of the spacecraft is at the sampling time (1 sec resolution) closest to the specified time. The data is read from default URI, and once the data is read from file, it is cached.

irfpy.cy1orb.pvat.getmepos(t)[source]

Get s/c position in ME frame as an array of [lon,lat,height]. lon and lat is in degrees, height is in km above the surface.

>>> me=getmepos(datetime.datetime(2009,4,18,1,30,0))
irfpy.cy1orb.pvat.getlsevec(t, vec_in_sc)[source]

Get LSE-frame vector correspoinding to the SC-frame vector at the time of t.