[AstroPy] problems with astroplan

[Gautham Narayan]

Hi Steven,

Maybe I'm missing something but you're example is supposed to print True 
and then False. That's what is in the comments even.


print(kpno.target_is_up(start_time, target))
# should print True

print(astroplan.is_observable(constraint, kpno, target[:1], 
times=Time('2016-11-11')))
# should print false.

Cheers,
-Gautham




On 11/07/2016 12:43 PM, Steven Boada wrote:
> Hi Eric,
>
> I apologize for my example not working. That is what I get for typing 
> it out in the same console I had been testing things in. Here is a 
> much more complete example.
>
> I've specified the timezone, but it still prints True and then False.
>
> import astroplan
> from astroplan import Observer, FixedTarget
> from astroplan.constraints import AtNightConstraint
> from astropy.coordinates import SkyCoord
> from astropy.time import Time
>
> # make telescope location
> kpno = Observer.at_site('KPNO', timezone='MST')
>
> # make target coordinates
> coords = SkyCoord(131.1331774, 62.41165761, unit='deg', frame='icrs')
>
> # make all the targets
> target = [FixedTarget(name='test', coord=coords)]
>
> # make the observing time
> start_time = Time('2016-11-10 18:54:00')
> end_time = Time('2016-11-11 5:27:00')
> time_delta = end_time - start_time
> observable_time = start_time + time_delta * np.linspace(0,1,75)
>
> print(kpno.target_is_up(start_time, target))
> # should print True
>
> # now we try to do all the fancy scheduling
> # set our only constraint to be at night
> constraint = AtNightConstraint.twilight_civil()
>
> print(astroplan.is_observable(constraint, kpno, target[:1], 
> times=Time('2016-11-11')))
> # should print false.
>
> Thanks again.
>
> On 11/07/2016 02:36 PM, Eric L. N. Jensen wrote:
>> Hi Steven,
>>
>> Since you don’t specify a timezone on your start_time variable, I’m 
>> guessing that it is probably being interpreted as UTC, in which case 
>> your specified target isn’t up at KPNO.
>>
>> You don’t show an import statement that would define your call to 
>> “Time” so I’m not 100% sure what routine it is and how it’s 
>> interpreting the specified time, but being sure about timezones is 
>> where I’d start troubleshooting this.
>>
>> Eric
>>
>>
>>> On Nov 7, 2016, at 2:22 PM, Steven Boada <boada at physics.rutgers.edu> 
>>> wrote:
>>>
>>> Hi list,
>>>
>>> I'm headed to KPNO and I'm trying out astroplan for the first time. 
>>> But I'm getting some confusing output. Here's an example.
>>>
>>> from astroplan import Observer, FixedTarget
>>> from astropy.coordinates import SkyCoord
>>>
>>> # make telescope location
>>> kpno = Observer.at_site('KPNO')
>>>
>>> # make target coordinates
>>> coords = SkyCoord(131.1331774, 62.41165761, unit='deg', frame='icrs')
>>>
>>> # make all the targets
>>> target = [FixedTarget(name='test', coord=coords)]
>>>
>>> # make the observing time
>>> start_time = Time('2016-11-11 01:54:00')
>>> end_time = Time('2016-11-11 12:30:00')
>>> time_delta = end_time - start_time
>>> observable_time = start_time + time_delta * np.linspace(0,1,75)
>>>
>>> print(kpno.target_is_up(start_time, target))
>>> # should print True
>>>
>>> # now we try to do all the fancy scheduling
>>> # set our only constraint to be at night
>>> constraint = AtNightConstraint.twilight_civil()
>>>
>>> print(astroplan.is_observable(constraint, kpno, targets[:1], 
>>> times=Time('2016-11-11')))
>>> # should print false.
>>>
>>>
>>> Looking up the airmass etc. on the web, the target is certainly 
>>> visible from KPNO. I'm obviously missing something, but I can't seem 
>>> to figure out what it is.
>>>
>>> Thanks for your help.
>>>
>>>
>>> steven
>>>
>>>
>>> -- 
>>>
>>> Steven Boada
>>>
>>> Postdoctoral Researcher
>>> Rutgers University
>>> boada at physics.rutgers.edu
>>>
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>


-- 
Dr. Gautham Narayan
NOAO/UA
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