COGO > Get COGO information

Get COGO information

Sometimes users may want to get some COGO information from SuperGIS Desktop, they can use the COGO tool. For example, they know the angle and the chord of a curve, and they want to know other measurements of the curve to help them create a new curve feature. They can use the Curve Calculator to get the necessary information. Other tools include Ground To Grid Correction, Report, and Area Calculator.

Ground To Grid Conversion

The survey data, including the directions and distances of line features, are measured on the surface of the Earth, which are called ground measurements. But the directions and distances of the line features in SuperGIS Desktop are projected data, which are called grid measurements. The two measurements are often different and need to be converted. Users can use the Ground To Grid Conversion tool to convert the data. Click to open Ground To Grid Conversion window, and enter the direction offset and distance factor to correct the data. If you don't know the two parameters, you can also use interactive ways to provide the information. One interactive way is to enter the direction and distance measured on the surface, and then click on the map to show the corresponding line on the map. To do so, choose 'Enter the ground line and click on the map for the grid line' and click icon next to it. Provide the direction and distance measurements first, and then click on the map to add the line.

The other interaction way is to click on the map to provide both the direction and distance measurements of the ground measurement and grid measurement. To do so, choose 'Click on the map for the ground and grid lines' and click icon next to it. Click on the map to add the line representing the actual line measured on the surface first, and then add the line representing the line on the grid.

Report

The Report tool help users to get the correction information according to the parameters set in the Ground To Grid Conversion window or measure the angle.

Report Line Measurements

Users can use or to get the line measurements. The first icon allows users to get the line measurements by drawing a line on the map, and the second one allows users to get the line measurements by selecting one existing line feature. The information includes the grid measurements and the ground measurements.

Report Angle

Users can use to measure an angle by drawing two intersected lines. Click the icon and click on the map to add the lines. Then the angle of the two lines will be shown.

Report Orthogonal Distance

Users can use or to get the orthogonal distance. The first icon allows users to get the orthogonal distance by drawing a line and a point on the map to calculate, and the second one allows users to select one existing line feature and draw a point to calculate the orthogonal distance. The information includes the grid measurements and the ground measurements.

Report Area and Perimeter

Users can use to draw a polygon and get its area and perimeter. The information includes the grid measurements and the ground measurements.

Report Coordinates

Users can use to get the coordinates of an existing point or line feature. Click the icon and select a point or line feature. The coordinates of the selected point or nodes of the selected line will be shown.

Area Calculator

The Area Calculator calculates the area of the selected COGO lines. To use this tool, users should first select COGO lines that form a closed polygon and click . The information includes:

▪Number of lines: number of selected lines.

▪Grid Area and Perimeter: the area and perimeter calculated using the grid measurement.

▪Ground Area and Perimeter: the area and perimeter calculated using the ground measurement.

▪Attribute Length: the sum of the distance attribute values of the straight lines or the arclength attribute values of the circular arc.

▪Misclosure As Direction/Distance: the line between the calculated endpoint and the start point of the traverse.

▪Relative Error Ratio: the length of the misclosure length/arrtribute.

▪Adjustment Method: the selected adjustment method.

▪Attribute Ground Area and Perimeter: the area and the perimeter of the adjusted traverse.

▪Attribute Grid Area and Perimeter: the grid area and perimeter multiplied by the distance factor.

Curve Calculator

The Curve Calculator helps users to get the curve measurements. Users only have to provide 2 of the curve measurement, such as angle and chord, to get all the other curve measurements, including angle, radius, arc length, chord distance, chord height, and tangent length.