Preparing Your Data for STAR*NET
The first stage of processing your data is to get it in a form suitable for importing into Star*Net. You can enter the data manually using a text editor, like Notepad, but this is time consuming and potentially prone to typing errors. n4ce can help you here by preparing the data in a format that is acceptable to Star*Net.
Multiple sightings to control points including FL/FR observations are meaned, with a spread about this mean being presented. This spread should be close to the Standard Error used in Star*Net. Note the three values shown below following the # comment. These are the spread about the Hz angle, Sl distance and Vt angle.
A number of different input formats are recognised by Star*Net. Two characters at the beginning of each line indicate what follows. In the example above DB is beginning of data set, DM is a direction with measured data and DE is the end of a direction set. Blank lines are ignored making the data file more readable.
Each data line can contain both compulsory and optional items, like standard errors. Some items can be 2D others 3D. If optional items are missing Star*Net will adopt defaults.
Standard errors are used to weight observations. These should follow the group of observations with a value for each observation. Special characters can be used to replace these values. For example the ! character indicates a fixed value whilst a * character is free. The & character or blank entries will take the default value indicated in the instrument options.
Star*Net requires control values before it can compute values. These can be in the form of fixed coordinates and/or directions. These can appear in a separate file, as shown below. The C indicates coordinates and note the ! character indicating a fixed value.
Once the data have been prepared, it needs to be attached to a Project, using the Input --> Data files option, shown below.
Data can be contained in a number of files and selectively introduced into the adjustment, on a what if basis. This is really useful if you're trying to ascertain the affects of individual readings. All data is accessed through a text editor as shown above, using controls indicated opposite. |
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