Field book processing

The GROMA program allows a complete processing of the field book containing the measured values including processing of the measurements in both positions of the binocular, measurements in two directions, etc.

After calling the command Measured data->field book processing a dialog window will display where you can set what changes you require in the field book.

Before the field book calculation, you must first define the theodolite using the command Settings->Theodolite. When defining the theodolite, you will set the tolerance for the measurement difference in the I. and II. positions of the binocular, the difference of the twice measured distance, etc. According to the set tolerances, the individual measurements marked in the report as suspicious or faulty are then performed.

The program is delivered with the predefined theodolite called "Unknown theodolite", in which the implicit tolerances for testing the suspicious and faulty measurements are set.

The information on all the changes in the measured data list is stored in a report. In some cases, it might be convenient to report the changes only in the report, but keep the measured data list in the original condition. In such case, check the option Only in the report, and the program will leave the list unchanged.

Also, you can choose whether to change the entire measured data list or only the selected items.

For the actual field book processing, press the button (Adjust). The program will step by step perform all the selected adjustments.

During the field book calculation, the program follows these rules:

Processing the measured data in both positions

On each station, the program will search for the direction pair to one point measured in both positions of the binocular. If it finds such a pair, it calculates the collimation error (measurement difference in both positions divided by two), and subtracts from this error the collimation error set in the theodolite definition. It then compares the result with the tolerances set in the theodolite definition.

The program will process the zenith distances (if measured) and lengths in the same way.

If all the differences meet the tolerances set in the theodolite definition, the program will adjust the measurement in the I. position so it contains the average values from both measurements.

Should at least one of the calculated differences be larger than the value set in the theodolite definition as suspicious, the program will mark the entire measurement in the report as suspicious.

Also the estimate of the real instrument errors is stored in the report after the processing of the measured data list.

Directions reduction

When reducing the directions, the program will adjust all the directions at the station so the direction is zero at the first orientation (first item on the measured data list), i.e. it will subtract the direction measured at the first orientation from all the directions.

Index error adjusting

If your instrument does not automatically adjust the index error and you know the amount of the error, set it in the theodolite definition and use this option to adjust the measured zenith distances.

Refraction adjusting

This option allows you to adjust the measured zenith distances or the horizontal difference by the influence of refraction and Earth curvature. Before the actual calculation, select the refraction coefficient and the adjustment you want to implement by pressing the button (Setting) the refraction coefficient, and which corrections you want to implement.

Horizontal difference calculation

After checking this option, the program will calculate the horizontal difference for all the measurements which contain distance and zenith distance and will store it in the measured data list.

Horizontal difference reduction on the connecting line between the stabilization marks

For the measurements with defined horizontal difference (or zenith distance), instrument height and target height, the program will calculate the horizontal difference directly between the points, i.e. the horizontal difference adjusted by the instrument and target heights. Afterwards, the instrument and target heights are set to zero to eliminate any further errors in the height calculation. This reduction must be performed before loading the data into height leveling.

Processing the repeated measured data

The program will search on each station for the measurement groups at the same target in the same binocular position and will calculate the final average measurement from the found distances. If the adjustments of the individual measurements meet the set tolerances, the program will remove the pertinent measurements from the list and adjusts the first measurement so it contains the average value.

Processing the distance measured in both directions and horizontal difference

For each measured distance, the program searches step by step in the entire measured data list for the pertinent distance measured in the opposite direction. If this is found, it calculates the average value, and if its adjustment does not exceed the set tolerances, it will store it to both measurements. It proceeds similarly for the horizontal difference.

If at least one of the calculated differences was bigger than the value set in the theodolite definition as suspicious, the program will mark the entire measurement in the report as suspicious.