obtain image coordinates. The program includes many operator 
aids to ensure blunder free measurements e.g. 
- default point numbering. 
- checks for duplicate point names. 
- digital transfer of common points. 
- automatic driving of the DSR to common points. 
- immediate display of model connections. 
The user may then carry out some preliminary adjustments, in 
order to check for any errors, using the polynomial adjustment 
programs in the AETRI package e.g. 
- strip formation. 
- polynomial strip adjustment. 
- block adjustment. 
After any computations are carried out, the results and 
residuals are displayed, and the operator has the capability of 
interactively editing the results. 
If necessary, models may be remeasured and the data reorganised 
to eliminate any repeated model measurements. 
A similar Kern Aerial Triangulation System also exists for the 
analogue instrument Kern PG2. 
7. DTM Collection and Processing 
The Kern DTM Collection Packages, DTMCOL and DOTXS, contain 
programs to define areas for data collection and collect 
information from the DSR in the form of regular grids, parallel 
profiles and user defined profiles i.e. 
- model window definition  - specify an area by 
coordinates or digitising in 
the DSR. 
- define multiple windows. 
- define windows within 
windows. 
- grid measurements - define grid spacing. 
- profile measurements - define parallel profile 
direction and spacing 
- define start and end points 
of user's profiles. 
- define spacing of cross 
sections and extent to the 
left and the right of the 
profile. 
- define which instrument 
controls are active for 
speed and height functions. 
- route design - define highway centre line. 
- define highway cross 
sections. 
18