Updating Elements

When updating element sets, Element Manager can treat Line0 in several different ways. You set these options on the Setup Screen and they are included in the initialization file (if you save it).

You can retain the line0 name in your master file while replacing lines 1 and 2 from a newer element set.

Some element sets may contain data on line0: Visual Magnitude, radar cross section data and perhaps the apogee and perigee data. You can retain the first 15 characters of the name in your master file and add this data if it is available in the updating file. While adding this data, EM looks for visual magnitude data. If it is NOT present in the updating element set but that set does contain radar data and/or apogee/perigee data, the program will retain the first 25 characters of the name in your master file and then add that data.

When you select Utilities/Update Elements from the main screen there are two initial options:

Include ILD check - EM will prompt you for a source file to update your current elements. The program will then look for matches of NORAD IDs in each file. If a match is found, the ages of the element sets are compared. If the source update file contains a newer element set the program then compares the International Launch Designator in each element set. If they match, the newer element set is imported. If the ILDs do NOT match this screen is displayed:

The current and updating element sets are displayed. The ILDs for each elset are displayed (for easier discernment of the mismatch). You are offered 6 choices for action on this (and possibly all remaining) element set.

In the "Do Not Update" box you can:

In the "Update Retain Old ILD" box you can:

In the "Update Replace ILD" box you can:

Ignore ILD - EM will prompt you for a source file to update your current elements. The program will then look for matches of NORAD IDs in each file. If a match is found, the ages of the element sets are compared. If the source update file contains a newer element set the program will replace line1 and line2 and depending you your choice all of line0, or part of line0 (as described at top) with the newer data.

Actually, selecting either of these opens another submenu with two choices.

Once the updating process completes this report screen is displayed.

The column on the left shows all element sets that have been updated. If you chose to add element sets that were not found in the active file then they are placed in this list with " - added" appended to them to indicate their inclusion.

The column to the right indicates which element sets have not been updated and gives the reason why an update was not done.

There are two reasons why an element set is NOT updated. 

1. The matching element set's epoch day in the active file is either the same as or more recent than the element set in the updating file, thus the indication, "active set up to date".

2. There is no matching satellite (by Norad ID) in the updating file, thus resulting in a "not found" indication.

The results in the skipped column should always appear in sorted order with the catalog numbers of all up to date element sets shown first in ascending order, followed by those elements not found in the updating file in ascending order.

Once you have started the update procedure, regardless of any action you take, the freshest element set is always the one remaining active in the program. However, you can make one of three possible choices after the update is finished. You can 

1. Click on "Save to File" and save the newly updated elements to the file you loaded, thus updating it on disk

2. Click on "Discard Updates Revert to Original File" and the elements in memory are discarded and the original file reloaded.

3. Click on "Save to Memory Only" and return to the main screen with updated elements active.