Re: My first set of image sequences of identified SATs

From: Gonzalo Blasco via Seesat-l <>
Date: Thu, 30 Apr 2020 13:51:51 -0500
Hi Marco,

I didnt catch  Qased (45530 )


I check the passes of satellites at CALSKY and sometimes at Heavens
Above... if you have any hint for better SW for the calculations are

The Calsky prediction said that Nour (45529) was MAG 3.3 at 0235UTC
(Aprox), but Qased (45530 ) passed under my filter because the max Mag
calculations were 4.4. at 024554.

 At that exact time QASED was visible, i was preparing next sat
observations of the night, I think was CZ-2C R/B 31114 ....


This are my first days taking this photos, and I have not the DSLR here...
so I had to hack someway... :-)

About my equipment, I discovered a low cost solution for tracking
satellites. I use an iphone with a support, and a commercial app called
NightCap which manage the sensor of the iphone that is very sensitive.

The app makes automatic stacking of 1/2secs captures, and you can manage
whatever length in exposure. I am still making experiments of the best ISO
for a good S/N ratio, and is from 4000ASA to 7000ASA. The iphone camera is
f2.2 and have focus capabilities, so I have quite 1-2pixel stars. At ISO
5000 works well.

Of course I think is not reliable for Photometry, but for astrometry, I
have checked that the exif data in the TIFF gives a very good precision,
You have only to make a photo of a precision clock and check afterwards the
EXIF metadata....


I manage intervals of 5secs at 5000 asa for asteroid tracking, and works
with passes at mag 3 at least. I have to check without moon. Now is quarter
and is a quite bright background!!!

With fainter asteroids I work with 10secs exposures intervals.

For flares I do longer (180-240 secs)

With the moon at quarter I manage to capture quite well stars at

max mag  5.50 with 5sec exposures.
max mag  5.80 with 20sec exposures.
max mag  6.60 with 60sec exposures.    (stacking corrects the motion of
stars if you zoom)

(of course the max mag in trails are reduced, but I have to do more
experiments to report how much)

I think if is not the ideal, but with correct star references I think the
astrometry can work fine.

Also is fun to make science with everyday objects.... used in another way

Gonzalo Blasco Gil

El jue., 30 de abr. de 2020 a la(s) 04:43, Marco Langbroek ( escribiĆ³:

> Op 30-4-2020 om 11:22 schreef Gonzalo Blasco via Seesat-l:
> >   Still looking NOUR 01 in the images, It should passed in the frame, but
> > at less than 10 degrees from the moon, so the S/N ratio are really poor
> , I
> > think the R/B is too faint for my camera, or simply the calculations are
> > wrong....
> The QASED r/b is brighter than NOUR 1.
> What lens/camera combo are you using?
> If you run windows, there is software to generate IOD format easily on my
> website
> - Marco
> -----
> Dr Marco Langbroek  -  SatTrackCam Leiden, the Netherlands.
> e-mail:
> Cospar 4353 (Leiden):     52.15412 N, 4.49081 E (WGS84), +0 m ASL
> Cospar 4355 (Cronesteyn): 52.13878 N, 4.49937 E (WGS84), -2 m ASL
> Station (b)log:
> Twitter: _at_Marco_Langbroek
> -----
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