The structure stands 9' 4" feet tall and is 7' 6" feet in diameter. It is made of marine grade fiberglass and is manufactured by Sirius Observatories in Australia. The shutters, dome and telescope are motorized, and allow for full computerized remote control from any terminal that has access to the observatory's network. Thus the Observatory is classified as a Robotic Telescope with Real Time Remote Accessibility (RT-RTRA).
The observatory features an adjustable pier on which the 12" Advanced Ritchey-Chrétien and a 4" refracting telescope sits. The Pier-Tech2 is adjustable in height from a low of 28 inches to a maximum of 48 inches. This will allow the user to stand or sit during visual observation sessions. It also allows children to be comfortable when using the telescope. One of the the tasks the observatory performs from time to time is deep space imaging. For deep space imaging to be successful the telescope must be aligned to the celestial north pole (the North Star - Polaris). This alignment is known as polar alignment.
The polar alignment, which is an equal to the angle of the latitude of where the scope is located is accomplish by attaching the telescope Optical Tube Assembly (OTA) to a German Equatorial Mount (GEM). The Paramount ME made by the Software Bisque is a computer controlled, robotic mount attached to a custom adapter plate manufacturer by Pier-Tech. The plate is bolted to the top of the pier head. The precision mount is critical for remote operation and for deep space astrophotography. Deep space imaging can require long exposures of up to an hour or more. (This time lapse image of the Asteroid Vesta required 8 hours.) During these exposures the telescope must remain in near perfect alignment (within a few arcseconds) and without being subjected to any vibrations. To help achieve this, the pier is isolated from the observatory floor, and mounted to an 18x18x36 inch concrete block buried in the ground.
To assist with astro-imaging the observatory uses a Adirondack Flat Fielder light panel. The approx 1/2 inch thick panel is attached to the south wall of the dome. The light box is used as part of the calibration during the imaging process. The light panel removes the effects of dust motes, uneven illumination of the imaging chip and vignetting. When the scope is parked and the dome is in the homed position, the height of the motorized pier is adjusted so that the scope's aperture is in front of the Flat Fielder. The light output level can either be remotely controlled by a PC or locally set by a hand controller. Ten calibrated output settings can be selected by the PC or the hand box. If the PC is used there are also 255 uncelebrated setting available. Without the box the "flats" would have to be taken by pointing the scope at a clear spot in the sky at either dusk or dawn. The problem with the sky method is there is only about a 15 minute window in which the flats can be taken. The sky must be dark enough so it doesn't overexposure the CCD chip but not so dark that stars show up in the background.
Power to the observatory is in the form of 120 volt AC and a 12 volt DC battery/ photovoltaic system. The DC power is supplied by means of two, 12 volt DC, 110 amp hour, deep-cycle marine batteries, connected in parallel. The batteries are recharged by a 28.8lb, 57.3" x 28.8" x 1.93" BP Solar panel capable of producing 110 watts of power @ 16.4 volts in direct sunlight. The charging is controlled by a ProStar solar charge controller. The controller provides the proper charge rate by using Pulse Width Modulation to vary the current from the solar array and taper it according to the batteries’ condition and recharging needs. This helps charge the batteries more efficiently as well as extend the life of the batterie. The dome rotation, some of the CCD cameras, and the florescent interior lights are 12 volt DC powered. In addition the batteries are connected to a 1200 watt (2400 watts peak power) AC to DC inverter. The inverter is used as a source of emergency AC power should the AC main power fail. The AC line powers the Pier-Tech 2 adjustable height pier, the PC, a 10 & 15 amp 12 volt DC power supply, the Paramount ME, some CCD cameras, and the red and white incandescent interior lights. The power for dew heaters for the main OTA corrector plate, guider scope, finder scope and eyepieces are provided by one of the 12 volt power supplies. Critical AC systems are on a battery backup. Rotation power for the dome is also supplied by the 12 volt DC 15 amp power supply but can be switched to the marine batteries. The dome's hatches have their own separate, smaller 12 volt DC battery, and 11 watt solar charging system built into the dome.
A Velleman 4 channel data logger is used to monitor the main battery voltage, solar panel output voltage, 15 amp Main 12 volt DC Power Supply voltage, and the 10 amp Pier Power 12 volt DC power supply voltage. The data logger is connect to the observatory PC via a USB port. The data can be displayed in numerical and graphical format. A text file can also be logged to disk.
The Power Layout diagram shows how the DC power is distributed in the observatory. The computer, monitor and RF remote switches are connected to an uninterruptible power supply (UPS). The UPS has been modified to use a 17 amp hour 12 volt battery to give the system a longer survival time should the main AC power fail. The UPS will execute a controlled shutdown of the computer after 45 minutes of an AC power failure. This reduces the possibility that a bad command could be received by the telescope causing a runaway slew condition if it is being controlled by the computer.
To control humidity inside the observatory a dog house heating and Air Conditioning unit was installed. The unit is automatically switched off and on when the dome is opened or close. If the humidity control only is desired a standalone dehumidifier can be switched on. When in use a programmable IGS-030 controller switches AC power to the dehumidifier when the relative humidity rises above 55%. For fully automatic and unattended operation of the dehumidifier, an external drain hose was connected to the dehumidifier unit.
Since the observatory is capable of unattended computerized control it was necessary to install a cloud sensor that would detect the presence of clouds. The Boltwood Cloud Sensor will differentiate between "Clear", "Cloudy", "Very Cloudy", "Rain" or "Snow". The sensor does this by using a thermocouple to measure the local ambient temperature. An Infrared (IR) sensor is used to measure the ambient sky temperature. The unit then compares the difference. The sensor has been configured at the observatory so that when a sky temperature of less than approximately -60 degrees F is detected the sky is defined as "Clear". More than -60 is defined as "Cloudy" and more than -18 degrees is seen as "Very Cloudy". The detector's data is plotted over time in order to tweak the cloudy threshold setting. Rain and snow are detected by a sensor plate that measures a change in resistance when moisture comes in contact with it. When the sensor detects moisture the plate is heated to approx 158 degrees to evaporate the moisture. When either a Very Cloudy or Rain/Snow condition is detected the sensor triggers a relay circuit that will automatically close the shutters via a wireless shutter control box. Within 90 seconds from the time a close condition is detected the shutters will be completely closed. This ensures that foul weather does not damage any equipment within the observatory.
The observatory is also equipped with a device know as a Sky Quality Meter (SQM). The SQM provides the observatory with the capability of measuring how dark the local stay is, and displays that data in magnitudes/arcsec2 (MPSAS), and as Naked Eye Limiting Magnitude (NELM).
In addition to being an astronomical observatory it also functions as a local weather station. Temperature, wind speed, wind direction, humidity and rain fall are all logged. The data is used my the observatory as well as uploaded to the internet and ultimately makes its way to the National Weather Service. More info about this can be found on the Weather Station page.
The observatory also receives a vast amount of information about space weather via Solar Terrestrial Dispatch Space Weather Information Monitor software (STD SWIM). This information is download at regular intervals to the observatory's weather computer. This information contains alerts and data about solar activity, such as the Solar Wind Sun Spots, Solar Flares, and the Aurora Borealis. The software can be customized to retrieve data or images from just about any website. The data does not have to be limited to space weather. One of the ways this software is used by JATO is to retrieve images provided by All-Sky cameras from various observatories around the world. For a complete explanation of the SWIM software click on the link above.
For photos of the construction and more info about some of the features of the observatory click here.
Go to the JATObservatory Home page
Updated 07/11/2015 - Please report broken links firstname.lastname@example.org