JATObservatory All Sky & Meteor Cam
Hopefully you are seeing a clear sky with stars and not a cloudy sky. If you watch long enough you will see aircraft, satellites or a meteor. They show up as streaks across the sky. The really bright long streaks are usually planes. The dimmer long streaks are satellites. The meteors usually show up as short streaks with medium to dim brightness. The satellites are visible just after it gets dark and just before it gets light. The meteors can appear pretty much anytime. After 10:30 of 11:00pm local time the aircraft traffic will diminish.
A big round bright white circle is the Moon. If the circle has a black background with a vertical spike, that means the pixels in that column have been saturated. This happens when one area of the camera's CCD chip has been exposed to a bright light such as the moon. If the bright circle has a light background covering the rest of the screen that indicates the moon is out, but the sky is very cloudy.
If the image is all grey or white with no curves at the edges, or full of horizontal lines, that means the camera is being exposed to a sky that is too bright. This will occur if the camera is started before it gets dark, or does turn off and continues to run after dawn. (That really shouldn't happen as I have adjusted the start and stop times so the only captures images when it dark enough.)
It is also important to know the image you were looking at is not processed. No dark frame subtraction, no bias frames , no flats. So that means you'll see dust modes, water spots reflections and noise (Because of the increase in temperature during the summer and because the Meteor Cam is not equipped with a Peltier cooler, more little white specks can be seen in the image, the specks are known as dark current noise). There is a lot more info buried in the image than what is shown on the website. The image on the website is a JPG and it compressed to be web-friendly. Images are archived for at least 30 days.
If the image is static and doesn't update that
means the camera
is not connected to the internet. The reasons this will occur are:
1. I decided its so cloudy it is not worth wasting bandwidth to upload pictures of the underside of clouds.
2. The computer or camera it is attached to decided to go on an unauthorized coffee break.
3. The camera is being used to capture meteors and satellites. That is what the camera was actually purchased for. When the camera is being used by the observatory in meteor mode no real time images are uploaded to the website. A message will be displayed on the website notifying users the camera is in Meteor Mode (if I remember to put it there).
learn a bit more info about the camera and to see a movie of the night sky from
this camera click here.
The All Sky camera image is also displayed on the Sky Quality Meter data page. The SQM measures how dark the sky is. Simply put the darker the sky, the more the observer can see. The SQM data displays data from the SQM in 30 minute intervals.
The Boltwood cloud and temperature chart was included on this page as a comparison for the All Sky Cam. You can use the "Clear Sky and Temp Graph" to verify the local sky conditions as well as what the All Sky cam is seeing. If the image is washed out with a lot of white that's a sure sign it's "very cloudy". You can check the graph for verification. If will show you if the sky is "Clear", "Cloudy" or "Very Cloudy". (It should be noted the camera can show high clouds that are not easily visible to the naked eye or that aren't visible to the cloud sensor at all.) The graph will also tell you if there is "Rain" or "Snow" present, along with the current temperature. If the image has spots or looks a bit like Swiss Cheese around the edges check to graph to see if it has rained recently. If so the filter more than likely has not dried off yet. What you are seeing are drops of water on the filter cover glass. The filter cover is heated but is not enough to quickly dry the cover. The heater does prevent condensation. The AC power supply also generates heat that helps with the condensation. Unfortunately since it sits below the camera it warms the CCD chip and helps produce noise.
The Clear Sky Clock is a prediction of what the sky will be like up to 3 days in advance. You can use the All Sky image and the Boltwood graph the see how accurate the Clear Sky Clock really is.
When the All Sky camera is active the image above will auto-update every 60
seconds. The camera takes a 20 second exposure, downloads the imaged from
the camera to the harddrive. It saves the images as a JPG file and then uploads
it to the website. It then waits for 60 seconds and starts the process
again. It continues this process until sunrise. The camera is operated by a
script running under CCDSoft V5 control. The software is automatically started
and stopped everyday be the Windows scheduler. The scheduler has to be adjust a
couple of times a year to account for the different sunrise and sunset times as
the seasons change.
A special thanks goes to Ron Wodaski for providing the "plug-in" for CCDSoft that allows the image to be saved in JPG format which is web friendly.
Feel free to tell me what you think about the camera.
Click or use yor browser's back button to return to the All Sky Camera page.
Go to the
Images are copyright protected and property of the JAT Observatory. They may not be used or reproduced in any manner without permission.
Updated 03/10/2013 - Please report broken links firstname.lastname@example.org