Re: [Orekit Developers] FieldOfView Detector

[Luc Maisonobe <Luc.Maisonobe@c-s.fr>]

Le 18/01/2016 15:16, Luc Maisonobe a écrit :
> Hi Evan,
> 
> Le 15/01/2016 09:25, Luc Maisonobe a écrit :
>> Le 14/01/2016 22:11, Evan Ward a écrit :
>>> Hi Luc,
>>
>> Hi Evan,
>>
>>>
>>> I noticed your recent work on the new field of view classes. I think
>>> these are a great addition. Would it be possible to model an antenna
>>> attached to a ground station? I think the current implementation of
>>> FieldOfView requires a spacecraft state.
>>
>> You caught me red handed!
>>
>> I am also not really comfortable with the spacecraft state in the
>> offsetFromBoundary method. It induces a dependency that is not
>> right. It is currently used to convert the input position into
>> a line of sigth, and this computation should better be performed
>> at call site, not within the method.
>>
>> I'll fix this in a few minutes.
> 
> I think I will reintroduce a method dedicated to the case the Field Of
> View is spacecraft centered. It will be something like:
> 
>  List<GeodeticPoint> getFootprint(SpacecraftState state,
>                                   OneAxisEllipsoid body);
> 
> I think it will be better here than for example in
> FootPrintOverlapDetector because there is no predefined geographic zone
> here and the method is expected to be called typically from a
> StepHandler throughout propagation.
> 
> Do you agree with this new method?

Also if we add this method, do you think FieldOfView should remain in
the events package? Perhaps it should be moved to utils (but utils
is already quite crowded an unstructured).

best regards,
Luc

> 
> best regards,
> Luc
> 
>>
>> I did not foresee using this for ground stations! Once the method
>> signature is fixed, it may be used this way too. Would you mind
>> updating the javadoc to explain this other use? I don't know
>> either if the name FieldOfView is well suited in this case, so maybe it
>> should be renamed at the same time.
>>
>> best regards,
>> Luc
>>
>>>
>>> Best Regards,
>>> Evan
>>>
>>
>