Filter
Top Products
- 6 -
system’s computer memory. It is also necessary to learn the
menu structure of the Keypad Hand Controller, which is
described beginning on page 8.
Basic CDS Setup:
This section explains what keys to push to get the minimum data
required into the computer system, without any detailed
explanation. The detailed explanation can be found later in the
manual. These steps will only take a few minutes and will allow
immediate use of all of the CDS features.
In order for the CDS to utilize the stellar coordinate system,
Right Ascension (R.A.) and Declination (Dec), the system needs
to know three pieces of information: the location (latitude and
longitude) of the observing site; the local time; and the date.
This information only needs to be entered one time — the CDS
remembers the data even when the power is off.
1) Entering the Latitude and Longitude of the Observing
Site.
The position of your observing site should be determined as
accurately as possible, to within 1 or 2 minutes of arc in both
latitude and longitude. Many automobile, pilot, and
topographical maps, as well as most atlases show latitude and
longitude in 15 minute increments or better. The accuracy of the
CDS depends on the accuracy of the data that is entered.
Once the above information is determined, it is easiest to enter
the data into the system while the telescope and CDS are
indoors where there is light—do not try to do it outside at night.
The following example is for an observing site in Costa Mesa,
CA (LAT=33°35', LONG=117°42'). If a mistake is made during
entry, simply turn off the telescope and restart this procedure.
(A more detailed description of the procedure shown below can
be found on page 11, "SITE".)
1. Turn "On" the #1697 CDS. After a few seconds (after the
self-diagnostic test is complete), the display will look like
Display 1.
→1) A A A ✔
2) A A A
→1) A A A ✔
2) A A A
→LAT = +00° 00’
LONG = 000° 00’
LAT = +33° 35’
→LONG = 000° 00’
LAT = +33° 35’
→LONG = 117° 42’
Display 1
2. Press the ENTER key to select the TELESCOPE functions.
The display should look like Display 2.
Display 3
4. Press and Hold the ENTER key until the Keypad Hand
Controller beeps. This selects the first site for editing. The
display should look like Display 4, with the first “A” flashing
NOTE: To edit the letters "AAA", press the NEXT or PREV keys
on the Keypad Hand Controller to cycle through the letters of the
alphabet. Use the "E" and "W" keys to move between positions.
Display 4
5. Press the ENTER key. The display should look like
Display 5. (Number values may vary.)
Display 5
6. Use the number keys to enter your latitude. Mistakes may
be corrected by moving the curser back, using the “E” and
“W” keys. A negative latitude may be entered by
positioning the cursor under the “+” and hitting the NEXT
key. When the latitude is correctly entered, press ENTER.
The curser moves to the LONG line. The display will look
like Display 6.
→TELESCOPE
OBJECT LIBRARY
→1) SITE
2) ALIGN
Display 6
7. Use the number keys (as described above) to enter your
longitude. When complete, the display will look like
Display 7.
Display 2
3. Press the ENTER key to select the SITE functions. The
display should look like Display 3.
Display 7
NOTE: The longitude standard used in the CDS starts at 0
degrees in Greenwich U.K. and increases Westerly only to 359
degrees 59 minutes. Many maps will show Easterly longitudes
which cannot be entered into the Keypad Display (e.g., if the map
indicates an observing site at an Easterly longitude of 18 degrees
27 minutes, it is necessary to enter the position as 341 degrees
33 minutes).
The differences in longitude and latitude as they pertain to
different map spheroid projections are minor differences that are
too small to adversely affect the longitude and latitude data input.
8. Press ENTER to complete the site information input. The
display will go back to Display 3.
9. Press MODE to go back to Display 2.
10. Press MODE again to go back to Display 1.
2) Entering the Local Time and Date.
The local time should be set as accurately as possible using the
24 hour format. The pointing accuracy of the telescope depends
on the accuracy of the time entered because the local time and
date are used to determine sidereal time (star time). Choose a
reliable source as a reference for accurate time such as your
local airport, or telephone company. In the U.S.A. you can double
check the accuracy of the exact minutes by dialing WWV for the
universal coordinated time at (303) 499-7111 (be sure to enter
your local time hour information, not the U.T. hour).
The following example is for 4:25:00 P.M. on Jan. 15, 1998.
1. The display should look like Display 1. If it does not, press
the MODE key until it does.