Software Bisque Knowledge Base Article – 68

OBJECT ID’S ALT/AZM INCORRECT FOR NON-MODERN TIMES

ISSUE

Although the Sky Display represents the accurate altitude/azimuth for an object, the Object Information dialog’s Alt/Azm data is increasingly inaccurate, the farther the date is from A.D. 2000.

RESOLUTION

TheSky v4.00.105 (and prior) is not precessing the altitude/azimuth values reported in the Object Information dialog.

This has been corrected in a pre-release version (4.00.200), which is not available for distribution. A new version of TheSky (v4.2?) will probably be released sometime this fall, which, in addition to many new features and enhancements, addresses this issue. This will be available as an inexpensive upgrade to registered v4.0 owners.

In the meantime, here are two work-arounds:

1. Obtain Object Information on the object of interest, and find the Epoch 2000 coordinates.
2. Without closing the Object Information dialog, use the Data, Add User Data command to add an object with the coordinates from step 1, but use the Precess button to precess these from the “current” year to 2000 (e.g. -275 to 2000).
3. After closing the Add User Data dialog, locate and click on your new object (it will be a red “+” symbol if you used object type Reference Point).
4. The reported information (alt/azm, rise/transit/set) will be correct for your original object at the “current” time.

Or:

1. Obtain Object Information on the object of interest, and find the Epoch 2000 coordinates.
2. Without closing the Object Information dialog, use the Orientation, Move To command to re-position the Sky Display at the coordinates from step 1, being sure to have the Epoch setting on “Current”.
3. Click on the center of the Sky Display, and the reported information for “Cursor Position” (alt/azm, rise/transit/set) will be correct for your original object at the “current” time. If you zoom to a 1′ field of view (press the (End) key) before clicking on the Sky Display center, this step will be more accurate.

APPLIES TO

General

KEYWORDS

SBKB

This article was formerly published under the identifier Q155KB in Software Bisque’s prior knowledge base.

Last Reviewed: 11/24/2004