Re: [Orekit Users] how to calculate iss passes

[Matteo <appdeveloper80@gmail.com>]

Hi Luc,
thanks for your fast reply. I've used TLEPropagator and now it's all right!
I'd want to ask if there is a way to calculate also brightness
(magnitude) of ISS.
Thanks again!

Matteo

2017-02-23 13:23 GMT+01:00 MAISONOBE Luc <luc.maisonobe@c-s.fr>:
>
> appdeveloper80@gmail.com a écrit :
>
>> Hi,
>
>
> Hi Matteo,
>
>> I'm trying to calculate iss passes over Rome and I start from propagation
>> tutorial and I write this code
>> (https://gist.github.com/anonymous/fb939c0df8e6a72282eb27cc76840ac9).
>> But if I compare the rise and set date with the Heavens Above prevision
>>
>> (http://heavens-above.com/PassSummary.aspx?satid=25544&lat=41.9028&lng=12.4964&loc=Roma&alt=53&tz=CET)
>> I don't find a match:
>>
>> My code finds:
>>
>> Visibility on station1 begins at 2017-02-23T14:06:33.974
>> Visibility on station1 ends at 2017-02-23T14:12:28.528
>>
>> Heavens Above calculates:
>>
>> 23 Feb  -       12:48:03        10°     NNW     12:50:12        16°     N
>> 12:52:20        10°     NE      daylight
>> 23 Feb  -       14:24:14        10°     NW      14:27:21        37°
>> NNE
>> 14:30:26        10°     E       daylight
>> 23 Feb  -       16:00:50        10°     WNW     16:03:44        29°     SW
>> 16:06:36        10°     SSE     daylight
>>
>> Note that Heavens Above times are in CET timezone.
>>
>> Can you help me where my error is?
>
>
> From a quick check, I see two things.
>
> First is that you created a Keplerian orbit from mean orbital elements and
> propagated them as if they were osculating elements. You will get tens or
> perhaps hundreds of kilometer differences after some propagation time.
> As Heavens Above used TLE, you should use TLE too for propagation, so you
> use the same semantic on parameters and the same model.
>
> Second, when copying the mean anomaly (131.4349), it seems you forgot to
> convert from degrees to radians.
>
> Hope thi_s helps,
> Luc
>
>> Thanks,
>>
>> Matteo
>
>
>