Astrel Instruments AST-8300-A User manual

Astrel Instruments AST-8300-A
Astrel Instruments
AST-8300-A
GETTING STARTED
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Getting started wit t e Astrel Instruments AST8300 camera
Thank you for purchasing an Astrel Instruments AST8300 CCD camera. Your new camera is a
lea ing e ge scientific instruments: please take your time to rea carefully the following User's
Manual to learn how to get the best out of your equipment.
The philosophy behin the AST8300 is the concept that the CCD camera coul be the real brain
of your astronomical equipment. This is possible thanks to the powerful microprocessor that is
in charge of managing not only the camera itself but also, through the exten e set of I/O
available on-boar , the other components of your system.
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Camera connections
The following picture shows the I/O interfaces available on the AST8300:
The following connectors are available on the camera:
•POWER SUPPLY: the camera nee s a 12V 3A power supply. The inclu e 3 meters
cable can be use to connect the camera to a car lighter using the inclu e a apter, or to
the optional 12V 3A power supply.
•ETHERNET: the camera can be connecte to a PC using a normal cat.5 Ethernet cable.
•LCD: this connector is use to attach the touch LCD monitor to the camera. Please pay
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attention to the polarization key inserte insi e one of the connector's pins: this is use to
avoi reverse connection that coul amage the camera.
WARNING: connect the LCD monitor only while the camera is powere own: connecting the
LCD when the camera is powere coul amage the monitor an the camera.
•USB FULL SPEED HOST: this 12Mbit/sec full spee USB connector can be use to
attach a wi e range of peripherals, inclu ing USB ongles, keyboar s an mice. A USB
hub can be use when multiple connections are nee e . It is typically use for the wifi
a apter
•USB HI SPEED HOST/DEVICE: this 480Mbit/sec hi spee micro USB connector can be
use to connect evices that nee s maximum ban wi th, like fast USB ongles or gui e
cameras. This connector is use as a host by efault in the current Linux istribution.
•EXT1: this is a 12 pin general purpose connector giving access to 3.3V an 5V power, an
SPI interface an one general purpose I/O pin that can be use to trigger external
evices.
•EXT2: this is a 10 pin general purpose connector giving access to 3.3V an 12V power, a
UART (serial port) connection which can be use for bringing the Linux serial console to
a PC, an an I2C port that can be use to connect the (not inclu e ) opto-couple mount
motors cable use for autogui ing or any other I2C evice.
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Powering up t e camera
To correctly power up the camera, please follow this sequence:
•When nee e , connect the touch LCD monitor paying attention to the polarization key.
•When nee e , connect the Ethernet cable to the camera an to the PC.
•When nee e , connect the wifi USB a apter using the USB port. The wifi a apter must
be connecte to the camera before power up in or er to start the wifi host access point
uring the camera boot sequence.
•Cables other than USB, for example the mount motors cable or the serial cable, can be
connecte an isconnecte at any time, but it's always a goo rule to connect any
nee e evice before power up.
•Connect the power supply cable.
After the power supply is connecte , the camera boots the Linux operating system an then
starts the Desktop application, from where all the camera's applications can be accesse .
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Powering down t e camera
WARNING: never power own the camera by simply isconnecting power supply: your camera
has a true PC insi e running Linux an , as any other PC, you shoul shut it own in the correct
way. The Shut own application in the main page of the Desktop will take care of all this
sequence, so, before powering own the camera you must run the Shut own application. At the
en of this application the system can be safely powere own.
The Linux istribution insi e the camera is store into the internal 8Gb SD car , which is the
main storage of the camera. In unlikely situations, removing the power supply while the
operating system or any application is writing on the SD car coul amage the files store on
it.
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Wifi and Et ernet operations
When the wifi USB a apter is connecte to the camera uring the boot sequence, the camera
becomes an access point, like a normal wifi router, that you can connect to using a
PC/tablet/smartphone. The wifi connection is open, no passwor require , an by efault the
network name is 'ast8300ap' while the ip a ress is 10.0.0.1.
When the camera is connecte using an Ethernet cable, the efault ip a ress is 192.168.0.18.
Your PC/smartphone/tablet shoul connect automatically when the camera powers up.
The network configuration can be mo ifie using the correspon ing application.
WARNING: remember to connect the USB a apter before powering up the camera or the wifi
network connection may not be establishe .
Once connecte , you can operate the camera in Connecte mo e like escribe in the
following paragraph.
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Stand Alone and PC/tablet/smartp one Connected modes
The AST8300 camera is operate using the collection of applications available on-boar , which
can be accesse using the touch LCD monitor in the Stan Alone mo e, or in the Connecte
mo e using any VNC compatible remote esktop application on a PC/tablet/smartphone with
Ethernet/wifi connection. There's only one set of applications for both the Stan Alone an
Connecte mo es, so the users on't nee to learn ifferent interfaces, the only ifference is
the way to interact with them.
These applications are collecte on the Desktop, which is organize in pages of icons
correspon ing to applications. When choosing one tab, a ifferent page of icons is isplaye .
The applications an tabs can be customize mo ifying the esktop.cfg fileHere follows a
screenshot of the main Desktop page:
The camera automatically senses the presence of the touch LCD monitor at boot. When the
monitor is not etecte , the applications are starte in VNC server mo e an can be accesse
by a VNC client.
When operate in Stan Alone mo e, the camera is very similar to any smartphone or tablet:
just touch the icon of the selecte application to start it or touch a tab to navigate to other
pages.
When operate in Connecte mo e, you only have to install a VNC client application on the
PC/tablet/smartphone, which is an application use to show the camera Desktop in a win ow in
the PC screen. There's no nee to install any river on the PC because the applications always
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run on the camera, not on the PC, an all the communications use Ethernet. This is why you
can run the same applications even with a tablet/smartphone.
Many free VNC client are available for many architectures: here follows a brief list of the teste
ones:
•PC/Win ows: TightVNC (http://www.tightvnc.com/)
•PC/Linux: TightVNC (http://www.tightvnc.com/)
•An roi : akRDC Free (available on the store)
•Win ows Phone: TinyVNC (available on the store)
To install them just follows the steps in icate on their websites.
WARNING: closing the VNC client application oesn't shut own the camera: the VNC client
only shows the camera applications on the PC screen. That means that you always have to run
the Shut own application before powering own the camera.
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Accessing t e camera storage
The camera main storage is the internal 8Gb SD car , where the operating system an the
photos are store . You can a more storage by simply connecting a USB ongle or even a
USB har isk to either USB connectors.
If you nee to access other fol ers (for example a USB ongle or har isk) or simply prefer to
use a file-manager like application, you can use any remote file-manager application using the
ssh protocol: here follows a brief list of the teste ones:
•PC/Win ows: WinSCP (http://winscp.net)
•PC/Linux: any file manager opening the location ssh://<camera ip a ress>
The username is root an the passwor is empty.
WARNING: when connecte with a remote file-manager application, you log in as root, meaning
that you have full access to any irectory an file, inclu ing the system ones so, unless you
know exactly what you're oing, avoi erasing or mo ifying any file which is not a FITS image
(extension .fits) otherwise you may severely amage the camera.
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Using t e touc LCD monitor
The touch LCD monitor is use in the Stan Alone mo e to operate the camera. It is mounte
on the back cover by means of an articulate mount which allows a proper orientation in every
telescope position. The monitor can be rotate aroun the connecting screw an aroun the
connecting tube.
Mount the monitor as in icate in the pictures below: start by mounting the connecting tube to
the back of the camera.
Then insert the monitor mount in the other en of the tube:
You can lock the monitor in the right position using the 2 white plastic knobs. Always be sure to
lock the monitor properly to avoi movement uring the exposures.
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Using t e vacuum pump
The AST8300 camera a opts a low vacuum approach to avoi frosting on the CCD glass, filters
an optical win ow. Using the inclu e vacuum pump, you can remove the air from insi e the
camera, so that there's no more water vapor to freeze on the CCD glass an filters. Moreover,
re ucing the air insi e the camera minimizes the heat exchanges ue to convection, so the
optical win ow never get too col ue to the low CCD an col finger temperature. The inclu e
pump is typically able to reach about 25 inHg vacuum in less than a minute of operation, but
anything above 23 inHg is enough. The vacuum pump gauges have a tolerance of about +/- 1
inHg, refer to the “Important Notice” sheet provi e with the camera to get the proper vacuum
level to be set before cooling the camera. The camera is teste to maintain a vacuum better
than 23 inHg for at least two ays an it's not unusual for cameras to last for weeks, so there's
no nee to operate the pump uring a photo session.
Always keep the vacuum valve close even when the camera is not working. When the camera
is not use for long perio s, it is a visable to put it into an air tight envelop.
WARNING: never get the camera below the freezing temperature without evacuating it to an
acceptable vacuum level: you will run the risk of frost creation on the CCD glass an even
pro uce a permanent amage to the camera.
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Tutorial: from power up to t e first p oto
This tutorial will gui e you in the process of making your first photo with the AST8300 camera.
We will use Win ows in Connecte mo e: most of the steps are the same also with Linux in
Connecte mo e, while many steps are not nee e in Stan Alone mo e.
STEP 1: evacuate the camera
•Screw the pump connection tube to the valve on the camera
•Insert the vacuum pump on the other si e of the tube
•Start pumping the air: if the vacuum level keeps going back to 0, push the pump nose as
much as possible insi e the tube an screw the tube as much as possible insi e the
valve, until the vacuum is retaine : this means that the pump is correctly connecte to
the camera
•Open the vacuum valve (the han le shoul be perpen icular to the camera back)
•Pump the air until a level of 25 inHg vacuum is reache
•Close the valve
•Rotate the knob near the nose of the pump to release the vacuum remaine insi e the
connecting tube, isconnect the pump an remove the tube
•The camera is now rea y for being coole below freezing temperature an the vacuum
shoul be retaine to an acceptable level for at least 2 ays
•You can check the vacuum level connecting the pump to the camera, pumping the air
until a level of 25.5 inHg vacuum is reache with the vacuum valve close to remove the
air insi e the connecting tube, an then opening the vacuum valve an rea ing the
vacuum level. Remember to close the valve before isconnecting the pump
STEP 2: power up the camera
Stan Alone mo e:
•Mount the touch LCD monitor an plug the flat cable to the LCD connector
•If nee e plug any USB evice an hub to the USB ports
•Plug the power supply
Connecte mo e:
•Plug the wifi USB a apter or connect the Ethernet cable to the camera an the PC
•If nee e plug any USB evice an hub to the USB ports
•Plug the power supply
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After booting (usually after less than one minute) the camera emits a soun an is rea y for
operation: the LCD monitor will isplay the Desktop in Stan Alone mo e, while in Connecte
mo e the camera is waiting for VNC connection.
STEP 3: connect to the camera
Only for Connecte mo e:
•When using wifi, look for the camera access point name (the efault one is ast8300ap)
an connect to it.
•Win ows will complain because the access is limite but this is normal because you on't
have an internet connection, only a local LAN connection.
•Start the VNC viewer. When prompte , insert the camera IP a ress (10.0.0.1:1 for wifi
or 192.168.0.18:1 for cable) in the Remote Host fiel , like in the following screenshot:
After connection, the TightVNC viewer win ow will isplay the camera Desktop:
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STEP 4: start the cooling process
•Start the Temperature Monitor application an insert the esire temperature set point,
then push the Start button. The application will work in backgroun maintaining the
temperature set point with a +/-0.1°C precision.
•Push Done to leave the application: leaving the application oesn't stop the cooling
process. Next time you open the Temperature Monitor application it will isplay the
current cooling process state, until you push the Stop button, which will ramp own an
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switch off the cooling process.
•The cooling process nee s some time to reach a stable temperature set point, so we will
use this time to fin an focus the object to photograph.
STEP 5: select a filterwheel position
•Start the Filterwheel application by clicking/touching the icon on the esktop, then push
the esire filter button an push go:
•Push done to leave the Filterwheel application.
STEP 6: find and focus
•Start the Fin & Focus application to focus the camera an frame the object. Push
liveview to start acquiring images. You can change the exposure time on the fly
epen ing on your target brightness: remember that the value refers to tenth of secon s,
so for 5 secon s exposure you have to write the value 50.
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•When in liveview, frame a me ium brightness star, push focus an you will be aske to
select the star in the fiel . After you touch/click the selecte star, the focus interface is
starte isplaying an enlargement of a small portion of sky aroun the star. The refresh
rate epen s on the exposure time an can be as fast as nearly 3 frames per secon
•The focus interface isplays the star along with a measure of the Full Wi th Half
Maximum an a plot of the intensity profile: use these parameters together with eye
inspection to focus the camera. You can change the exposure time an the enlargement
of the star fiel , as well as move aroun using the arrow buttons
•At the en of the focus process, in or er to verify the focus accuracy, it coul be useful,
when permitte by the precision of the mount motors, to set the exposure time to 15-20
secon s to possibly show many stars of ifferent brightness. This can also be one after
framing the object to photograph.
•Push liveview again to come back to the liveview interface an frame your object. With
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liveview taking images in 9x10 binning mo e, even an exposure of a few secon s easily
reveals most eepsky objects, making the framing process as easy as oing a portrait
with a conventional camera.
STEP : check temperature stability
•The cooling process shoul reach a stable set point temperature after 10-15 minutes
epen ing on the environment. The time nee e to reach the selecte temperature set
point may be shorter, but the algorithm nee s some more time to calibrate in or er to
maintain a temperature stable to less then 0.1°C. To check that the temperature is stable,
start the Temperature Monitor application again an monitor the temperature variations
for a while
•Push Done to leave the application an come back to the Desktop
STEP 8: set the exposure parameters and start photographing
•Stat the Take Photos application.
•Using the tabs name as the filters you set in the Setup application, you can efine for
each filter the exposure time, the number of exposures an the binning level. Remember
to check the enable box in or er to use the selecte filter.
•Select the rea out mo e between 2 an 16 samples: the 2 samples rea out has about
7.5e- rea out noise an about 10 secon s ownloa time, while the 16 samples rea out
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has about 5e- rea out noise an 35 secon s ownloa time
•Choose a photo sequence name. If you omit a path before the name, the photo
sequence will be store in the efault photo fol er, which is the 'photos' fol er. If you
want the photo sequence to be save in your external USB storage, browse to the
'usb/s a1' fol er. A vance user can use any existing path on the camera where they
have the permission to write
•Each photo of a sequence can be i entifie using its name. For example, the thir
exposure with the secon filter of the 'm31_lrgb' photo sequence will be save as
'm31_lrgb_filt2_3.fits'
•Start the photo sequence pushing the SHOT! Button.
Note: During photo ownloa from the cc the camera turns off the isplay, the wifi, the
ethernet an the fan in or er to minimize rea out noise. After the completion of the photo
(buzzer soun signals it) all these functions turn on again. Your PC or Smartphone coul nee
to restablish the connection to the camera.
•Using the Monitor application you can monitor the sequence execution
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•You can push the off button to turn off the LCD. To turn it back on, just push anywhere
on the isplay
•Push Kill to stop the photo sequence. You will be aske whether to stop only the current
exposure or the whole sequence
•Push Preview to see a thumbnail of the last exposure
•Push the Done button to come back to the Desktop
STEP 9: download the images to a PC
•The camera saves the photos on its internal SD car or on an external USB storage.
There's no nee to ownloa them on a PC uring the observing session: you can
copy/move the images to a PC in many ways, here follows the most common:
•Metho 1: use WinSCP:
•Open WinSCP an create a new connection.
•Choose SFTP protocol an insert the camera ip a ress, port 22 an your user name
an passwor
•Copy the files/fol ers as nee e
•Metho 2: If you store the photo sequences in an external USB storage, you can of
course isconnect it from the camera an plug it to the PC.
WARNING: never isconnect the USB storage before correctly unmount it using the Eject USB
application.
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