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| REQUESTING OBSERVING TIME AND DELIVERED DATA |
| How Do I Submit an Observing Request? |
As a user of the Tenagra II telescope you are assigned a place on our FTP server.
Each user uploads an ASCII file in a precisely defined format so that
the scheduler can read all requests and place them in optimal order. You just need to
specify the night(s) in which you wish to observe each target; the scheduler will choose suitable
observation times for each of your targets. |
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| Please follow these guidelines when uploading observation requests to our FTP
server: |
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Files containing observation requests must contain only observation
requests in the format to be described below. Each observation request consists
of a single line. Do not use tabs to format the columns. The name of files
that contain observation requests cannot have blank characters.
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Files
containing observation requests must have extension .txt
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Files containing observation requests must be uploaded to the root directory of your
FTP area, not to any subdirectory.
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Observation requests meant to be carried out on the next night at Tenagra must be
uploaded to our server before 22:00 UT. For example, if you wish to observe
some target on 2003 Sept. 20 UT, the deadline for uploading your observation
request is 2003 Sept. 19, 22:00 UT.
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After each uploaded file containing observing requests is processed by our software,
a receipt will be sent to you by e-mail and also placed in subdirectory /receipts of
your FTP area. You should check this receipt to see if your observing requests were
accepted; if some requests were not accepted, the reasons for the rejections will be
given. The receipt also lists the serial numbers assigned to each of your
accepted requests. These are unique numbers which identify each of your observing
requests in our internal bookkeeping system. |
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If you decide to cancel some of your observation requests, please contact us as
soon as possible, specifying the serial number(s) of the request(s) you wish to cancel.
The above 22:00 UT deadline also applies to the cancellation of user requests. |
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| Types of Observing Requests |
This section describes the five types of observation requests which we can accept
at this time. Click on the links below for a detailed description of the format
of each type of request.
- Non-solar system objects. This category includes every object that is not in the solar system (therefore not moving with respect to the stars), from the closest stars to the most distant galaxies.
- Solar system objects with a published ephemeris. Targets in this category must have ephemeris available at the Minor Planet Center's web site (at either the Minor Planet & Comet Ephemeris Service or at the NEO Confirmation Page). Our system does not require you to submit the ephemeris data, it automatically gets this data from the MPC web site.
- Solar system objects without a published ephemeris. These objects will usually be new, relatively slowly moving objects discovered by you or some other observer, which haven't yet received an official designation from the MPC, and therefore need to be confirmed on a second night. This option makes the assumption that the target moves slowly enough that a Väisälä ephemeris generated with the New Object Ephemeris Generator is accurate enough to get the object in the telescope field-of-view over a period of a few days after discovery. If you discover a fast moving object or a comet, you should report it to the MPC immediately, without waiting to get images on a second night.
- Mosaic searches for new solar system objects. This mode allows you to do a mosaic search for comets or minor planets. The Tenagra 0.81-m telescope allows you to easily discover minor planets whose magnitude is fainter than the limiting magnitude reached by the surveys LINEAR, NEAT, and LONEOS. You can confirm your (slowly moving) discoveries on a second night using observation requests of type (3). If you discover a fast moving object or a comet, you should report it to the MPC immediately, without waiting to get images on a second night.
- Spectra of non-solar system objects. It is now possible to request spectra of stars, galaxies, and other objects outside the solar system.
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| Delivered Data |
You will be notified by e-mail when some of your observing requests are carried out.
These notifications will also be placed in subdirectory /notifications of your
FTP area.
Your images will be placed in your FTP area as they are taken, in a separate directory
for each night and telescope. For example, your images taken with the 32-inch telescope
on 2003 Sept. 25 UT will be stored in directory /030925_32in. The directory
corresponding to a given night will contain the following subdirectories:
/images
/dark
/bias
/EveningFlat
/MorningFlat
Subdirectory /images contains your raw science images, which will appear in the
subdirectory as soon as they are taken by the telescope. If you wish to download
your images in near real time, you may use a FTP client (such as the Windows program Bullet Proof FTP) which can be configured to continuously
monitor the subdirectory /images and automatically download new images as they
appear. In this way, you can usually have all your night's data on your computer
soon after the images have been taken.
Your science images will be named AAAnnnnn.fit, where AAA is your 3-character user ID and nnnnn is a 5 digit number.
These numbers are not significant from the user's point of view.
All the information you need is in the FITS headers
of the files. Automated e-mail notifications are sent to you when
observation requests are carried out. They list (among other things) which
image files correspond to each of your observational requests.
You may choose between three options for compression of your science images: zip,
FITS compression, and no compression. Compressed images will lead to a reduction
of roughly 50% in download time. Zipped images may be unzipped with standard
programs such as pkZip, WinZip, etc. Opening FITS-compressed images requires the
Windows program MaxIm DL. If you use MaxIm DL for your image calibrations, FITS
compression is probably the most convenient compression method.
At the end of the night at Tenagra, a file named calibrate.zip is created in
subdirectory /images. This zip archive contains all the master calibration files (bias frames, dark frames, flat fields) which are necessary for the calibration of
your science images. The master bias and dark frames are obtained by median combining
three individual bias and dark frames, respectively. The dark frames have an exposure time
of 150 seconds; you are supposed to scale the master dark frames when using them to
calibrate exposures whose exposure times are not equal to 150 seconds. The master flat
fields are obtained from 3-15 individual sky flats, which are bias- and dark-subtracted and
then median-combined.
We automatically take flat fields in the morning and evening. Flats for R, V-band and
unfiltered are taken in the evening twilight and stored in subdirectory /EveningFlats.
Flats for B, I and U-band are taken in the morning twilight, following the
run, and stored in subdirectory /MorningFlats. If your observations do not include
images taken in the B, I, or U-band, all your flat fields will already be
available at the end of astronomical evening twilight at Tenagra. You may
of course use flats from a previous night if you wish.
Bias and dark frames are always taken in the evening before observations, and stored
in directories /Bias and /Dark, respectively.
If you do not wish to wait until the calibrate.zip file appears in subdirectory /images, you may retrieve your calibration files from subdirectories /Dark, /Bias, /EveningFlat, and /MorningFlat. We store both the individual calibration files taken
with the telescope and master calibration files which are produced by median combining
the individual calibration files. You will probably wish to use these master files
for your calibrations; the individual calibration files are provided in case you
wish to prepare your own master calibration files by combining the individual
calibration files.
Our naming convention for master flat fields is MasterFlat_binN_BAND_OPT.fit.
This looks a bit complicated but it isn't. All master flat frames have the prefix MasterFlat. Following this is the binning of your image. This is bin1 or bin2 for unbinned or 2X2 binning. BAND is the filter used: clear
(unfiltered), U, B, V, R, I,. OPT is an optional part of the name that will contain Center or not be present. Center means that the central 7.4 x 7.4 arcminute field of the CCD
detector has been used. Some examples: |
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| MasterFlat_bin2_U.fit |
Master U-band flat field binned 2X2 over the full 14.8 x 14.8 arcminute field of the CCD
detector (512 x 512 pixels). |
| MasterFlat_bin1_I_Center.fit |
Master I-band unbinned flat field over the central 7.4 x 7.4 arcminute field
of the CCD detector (512 x 512 pixels). |
| MasterFlat_bin1_V.fit |
Master V-band unbinned flat field over the full 14.8 x 14.8 arcminute field
of the CCD detector (1024 x 1024 pixels). |
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The names of dark and bias frames are quite similar except there is no BAND: MasterNAME_binN_OPT.fit, where NAME is either Dark or Bias.
Some examples: |
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| MasterDark_bin2.fit |
Master dark frame binned 2X2 over the full 14.8 x 14.8 arcminute field of the CCD
detector (512 x 512 pixels). |
| MasterDark_bin1_Center.fit |
Master unbinned dark frame over the central 7.4 x 7.4 arcminute field of the CCD
detector (512 x 512 pixels). |
| MasterDark_bin1.fit |
Master unbinned dark frame over the full 14.8 x 14.8 arcminute field of the CCD
detector (1024 x 1024 pixels). |
| MasterBias_bin1.fit |
Master unbinned bias frame over the full 14.8 x 14.8 arcminute field of the CCD
detector (1024 x 1024 pixels). |
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The names of individual calibration files follow these conventions:
Flat_binN_BAND_nnnn_OPT.fit
Dark_binN_nnnn_OPT.fit
Bias_binN_nnnn_OPT.fit
where binN, BAND, and OPT are as explained above and nnnn is a 4-digit number.
On rare occasions, bad weather or other problems prevent us from obtaining a full
set of calibration files. If this happens on a night when we have obtained science
images for you, you will notice that the calibrate.zip file either will not be
created (if none of your calibration files has been obtained) or will not contain
all the calibration files you need. In these cases, you should search the directories
which store the images from the past few nights, where you will normally find the
calibration files you need. Unless there has been a change in optical or camera
configuration, calibration images from a previous night will be virtually identical
to those taken on the current night.
If on a given night spectra are taken for you using the Tenagra spectrograph, additional
data files and spectrograph calibration files are placed in your FTP area. Click here for details.
The directory corresponding to any given night is kept on the FTP server for 10 days,
and is then moved to another computer for back-up storage. If you need to download
data which is more than 10 days old, please contact us,
so we can temporarily restore
it to the FTP Server.
If some of your images are seriously affected by clouds, please send us an e-mail mentioning
the UT date when the images were taken and the file names of the affected images,
so we may provide a refund. |
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If you have questions about the the observation request format or about the above processes please e-mail them to mbs@tenagraobservatories. |
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