Astrel Instruments AST8300X User manual

Astrel Instruments AST8300-X
Astrel Instruments
AST8300-X
GETTING STARTED
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Astrel Instruments AST8300-X
Getting started ith the Astrel Instruments camera
Thank you for purchasing an Astrel Instruments CCD camera. Your new camera is a leading
edge scientific instruments: please take your time to read carefully the following User's anual
to learn how to get the best out of your equipment.
The philosophy behind your camera is the concept that the CCD camera could 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 extended set of I/O
available on-board, the other components of your system.
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Camera connections
The following picture shows the I/O interfaces available:
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The following connectors are available on the camera:
•12V: the camera needs a 12V 3A power supply. The use of the included 3 meters cable
with its filter box is strongly suggested to connect the camera to a car lighter receptacle
using the included adapter, or to the optional 12V 3A power supply.
•USB 1&2: these two 480 bit/sec hi speed USB connectors can be used to connect
devices like USB dongles, guide cameras, keyboards and mice. USB hub can be used
when multiple connections are needed. Each USB port can drive max 500 mA.
•WiFi: this S A connector is used for the included WiFi Antenna.
•Flatbox controller: 12V controlled power out for powering your flatbox with the included
cable. The flatbox can be controlled using the flat maker app on the camera desktop
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Po ering up the camera
To correctly power up the camera, please follow this sequence:
•Connect the wifi Antenna.
•Connect USB devices. ost of them can be connected and disconnected at any time, but
it's always a good rule to connect any needed device before power up.
•Connect the power supply cable.
After the power supply is connected, the camera boots the Linux operating system and then
starts the Desktop application, from where all the camera's applications can be accessed.
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Po ering do n the camera
WARNING: never power down the camera by simply disconnecting power supply: your camera
has a true PC inside running Linux and, as any other PC, you should shut it down in the correct
way. The Shutdown application in the main page of the Desktop will take care of all this
sequence, so, before powering down the camera you must run the Shutdown application. After
pressing shutdown, the camera will disconnect from wifi and emit a certain number of regularly
timed weak beep sounds. When the beeps end the camera can be powered off unplugging the
power cable. In case the beeps can't be heard, after shutdown wait for 1 minute before
unplugging the power cable.
The Linux distribution inside the camera is stored into the internal SD card, 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 card could damage the files stored on it.
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Wifi operations
The camera acts as a WiFi access point, like a normal wifi router, that you can connect to using
a PC/tablet/smartphone. The wifi connection is open, no password required, and by default the
network name is Astrel_ap_ followed by the camera s/n while the ip address is 10.0.0.1.
WARNING: remember to connect the WiFi antenna.
Once connected, you can operate the camera in Connected mode like described in the
following paragraph.
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PC/tablet/smartphone Connected mode
The camera is operated using the collection of applications available on-board, which can be
accessed using any VNC compatible remote desktop application on a PC/tablet/smartphone
with wifi connection.
Astrel proprietary applications are collected on the Astrel Desktop, which is organized in pages
of icons corresponding to applications. When choosing one tab, a different page of icons is
displayed. The applications and tabs can be customized modifying the desktop.cfg file. Here
follows a screenshot of the main Desktop page:
Other third-party applications are available on the Linux Desktop.
When operated in Connected mode, you only have to install a VNC client application on the
PC/tablet/smartphone, which is an application used to show the camera Desktop in a window in
the PC screen. There's no need to install any driver on the PC because the applications always
run on the camera, not on the PC, and all the communications use the wifi connection. This is
why you can run the same applications even with a tablet/smartphone.
any free VNC client are available for many architectures: here follows a brief list of the tested
ones:
•PC/Windows: TightVNC (http://www.tightvnc.com/)
•PC/Linux: TightVNC (http://www.tightvnc.com/)
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•Android: akRDC Free (available on the store)
•Windows Phone: TinyVNC (available on the store)
To install them just follows the steps indicated on their websites.
WARNING: closing the VNC client application doesn't shut down the camera: the VNC client
only shows the camera applications on the PC screen. That means that you always have to run
the Shutdown application before powering down the camera.
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Accessing the camera storage
The basic camera main storage is the internal 8Gb SD card, where the operating system and
the photos are stored. You can add more storage by simply connecting a USB dongle or even a
USB hard disk to either USB connectors.
If you need to access other folders (for example a USB dongle or hard disk) 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 tested ones:
•PC/Windows: WinSCP (http://winscp.net)
•PC/Linux: any file manager opening the location ssh://<camera ip address>
The username is astro and the password is astronomy.
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Using the vacuum pump
The camera adopts a low vacuum approach to avoid frosting on the CCD glass, filters and
optical window. Using the included vacuum pump, you can remove the air from inside the
camera, so that there's no more water vapor to freeze on the CCD glass and filters. oreover,
reducing the air inside the camera minimizes the heat exchanges due to convection, so the
optical window never get too cold due to the low CCD and cold finger temperature. The included
pump is typically able to reach about 25-26 inHg vacuum in less than a minute of operation, but
anything above 24 inHg is enough. The vacuum pump gauges have a tolerance of about +/- 1
inHg, refer to the “Important Notice” sheet provided with the camera to get the proper vacuum
level to be set before cooling the camera. The camera is tested to maintain a vacuum better
than 24 inHg for at least two days and it's not unusual for cameras to last for weeks, so there's
no need to operate the pump during a photo session.
Always keep the vacuum valve closed even when the camera is not working. When the camera
is not used for long periods, it is advisable 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 and even
produce a permanent damage to the camera.
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Tutorial: from po er up to the first photo
This tutorial will guide you in the process of making your first photo with your camera. We will
use Windows in Connected mode: most of the steps are the same also with Linux in Connected
mode, while many steps are not needed in Stand Alone mode.
STEP 1: evacuate the camera
•Insert the pump connection tube into the vacuum pump nose
•Screw the pump to the camera's valve
•Pump the air until 25 inHg is reached: if the vacuum level keeps going back to 0, push
the pump nose as much as possible inside the tube and screw the tube as much as
possible inside the valve, until the vacuum is retained: this means that the pump is
correctly connected to the camera
•Open the vacuum valve (the handle should be perpendicular to the camera back)
•Pump the air until a level of 25 inHg vacuum is reached
•Close the valve
•Disconnect the pump and remove the tube
•The camera is now ready for being cooled below freezing temperature and the vacuum
should be retained to an acceptable level for at least 2 days
•You can check the vacuum level connecting the pump to the camera, pumping the air
until a level of 25 inHg vacuum is reached with the vacuum valve closed to remove the
air inside the connecting tube, and then opening the vacuum valve and reading the
vacuum level. Remember to close the valve before disconnecting the pump
•Note: the level of vacuum of 25 inHg could not be possible to reach on high altitude
locations. In this case pump the air until it can't get any lower
STEP 2: power up the camera
•Plug the WiFi Antenna to the camera and the PC
•If needed plug any USB device and hub to the USB ports
•Plug the power supply
After booting (usually after few secons) the camera emits a weak sound meaning that it is ready
for operation and waiting for VNC connection.
STEP 3: connect to the camera
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•Look for the camera access point name (the default one is Astrel_ap_<serial>) and
connect your device to it.
•Windows will complain because the access is limited but this is normal because you don't
have an internet connection, only a local connection.
•Start the VNC viewer. When prompted, insert the camera IP address 10.0.0.1 in the
Remote Host field, like in the following screenshot:
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Astrel Instruments AST8300-X
After connection, the VNC viewer window will display the Linux Desktop that includes the Astrel
Desktop and the icons of the thid-party applications:
STEP 4: start the cooling process
•Start the Cooling Control app and insert the desired temperature set point, then push the
Start button. The application will work in background maintaining the temperature set
point with a +/-0.1°C precision.
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•The cooling process needs some time to reach a stable temperature set point, so we will
use this time to find and focus the object to photograph.
STEP 5: select a filterwheel position
•Start the Filterwheel app clicking the icon on the desktop, then push the desired filter
button and push go:
•Push done to leave the Filterwheel application.
STEP 6: fin an focus
•Start the Find & Focus application to focus the camera and frame the object. Push live to
start acquiring images. You can change the exposure time on the fly depending on your
target brightness: remember that the value refers to tenth of seconds, so for 5 seconds
exposure you have to write the value 50.
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•When in liveview, frame a medium brightness star, push focus and you will be asked to
click on a star in the field. After you click the selected star, the focus interface is started
displaying an enlargement of a small portion of sky around the star. The refresh rate
depends on the exposure time and can be as fast as nearly 3 frames per second
•The focus interface displays the star along with a measure of the Full Width Half
aximum and a plot of the intensity profile: use these parameters together with eye
inspection to focus the camera. You can change the exposure time and the enlargement
of the star field, as well as move around using the arrow buttons
•At the end of the focus process, in order to verify the focus accuracy, it could be useful,
when permitted by the precision of the mount motors, to set the exposure time to 15-20
seconds to possibly show many stars of different brightness. This can also be done after
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framing the object to photograph.
•Push live again to come back to the liveview interface and frame your object. With
liveview taking images in 10x10 binning mode, even an exposure of a few seconds easily
reveals most deepsky objects, making the framing process very easy.
STEP 7: check temperature stability
•The cooling process should reach a stable set point temperature after 10-15 minutes
depending on the environment. The time needed to reach the selected temperature set
point may be shorter, but the algorithm needs some more time to calibrate in order to
maintain a temperature stable to less then 0.1°C
•Push Done to leave the cooling app when temperature is reached: leaving the
application doesn't stop the cooling process. Next time you open the Temperature
onitor application it will display the current cooling process state, until you push the
Stop button, which will ramp down and switch off the cooling process.
STEP 8: set the exposure parameters an start photographing
•Stat the Take Photos application.
•Using the tabs named as the filters you set in the Setup application, you can define for
each filter the exposure time, the number of exposures and the binning level. Remember
to check the enable box in order to use the selected filter.
•Choose a photo sequence name. If you omit a path before the name, the photo
sequence will be stored in the default photo folder, which is the '/home/astro/photos'
folder. Advanced user can use any existing path on the camera where they have the
permission to write
•Each photo of a sequence can be identified using its name. For example, the third
exposure with the second filter of the 'm31_lrgb' photo sequence will be saved as
'm31_lrgb_filt2_clear_3.fits'
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•Start the photo sequence pushing the SHOT! Button.
Note: During photo download from the ccd the camera turns off the wifi and the fan in order to
minimize readout noise. After the completion of the photo (a weak sound signals it) all these
functions turn on again. Your PC or Smartphone could need to reestablish the connection to the
camera.
•Using the onitor application you can monitor the sequence execution
•Push Kill to stop the photo sequence. You will be asked whether to stop only the current
exposure or the whole sequence
•Push Previe to see a thumbnail of the last exposure
•Push the Done button to come back to the Desktop
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STEP 9: ownloa the images to a PC
•The camera saves the photos on its internal SD card or on an external USB storage.
There's no need to download them on a PC during the observing session: you can
copy/move the images to a PC in many ways, here follows the most common:
•ethod 1: use WinSCP:
•Open WinSCP and create a new connection.
•Choose SFTP protocol and insert the camera ip address (10.0.0.1), port 22, your user
name (astro) and password (astronomy)
•Copy the files/folders as needed
•ethod 2: If you stored the photo sequences in an external USB storage, you can of
course disconnect it from the camera and plug it to the PC.
WARNING: never disconnect the USB storage before correctly unmount it (see the tutorial for
the procedure).
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