Copan News

Aug-2007

Regarding Copan Lite for Windows 07.08.

Transform Coords by Control Points Improved

There are two improvements to the Transformation by Control Points module.

First, the computed rotation and scale parameters are now with respect to a local origin (the centroid of the source control points). Previously, rotation and scale were with respect to the coordinate origin, often far from the points and resulting in less intuitive (albeit correct) values being produced.

Second, you now have a choice of transformation type to estimate: rigid-body or similarity. The rigid-body transformation has just a rotation and shift, with scale fixed at 1.0. The similarity transformation — previously the only option — has a rotation, a scale, and a shift.

Resection Processing Now Available

There's a new module to process raw total station surveys — circle readings, slope distances, and instrument and signal heights — based on resection (or free station) setups. Resections are calculated using the best-fit of angle and distance shots to control points. Multiple resection surveys can be computed within a single field file.

Calculation | Process Field Resections...

A resection survey consists of a setup line:

    at ={free stn}    HI= {instr ht}
    
Up to 10 "control shots":
        to= {1st ctrl pnt}   HC= {1st ctrl HC}   VC= {1st ctrl VC}    SD= {1st ctrl SD}   HS= {1st ctrl HS}
        to= {2nd ctrl pnt}   HC= {2nd ctrl HC}   VC= {2nd ctrl VC}    SD= {2nd ctrl SD}   HS= {2nd ctrl HS}
        etc
    
An end of resection line:
        end= resect
    
And various side shots:
        to= {1st SS pnt}   HC= {1st SS HC}   VC= {1st SS VC}    SD= {1st SS SD}   HS= {1st SS HS}
        to= {2nd SS pnt}   HC= {2nd SS HC}   VC= {2nd SS VC}    SD= {2nd SS SD}   HS= {2nd SS HS}
        etc
    
Note that HI and HS entries can be omitted for 2D observations.

Projection Scale Factors Now More Precise

The allowed input precision of projection scale factors in Field Data and Map Traverse families of modules is now 10 decimals. It was only 6 or 7.

Aug-2007