How to calibrate a map

How to Calibrate a map when using FarmMap

When you are using FarmMap for the first time, or using a new map, you will need to calibrate your map.

Step 1

• Open FarmMap
• Choose Calibrate from the popup menu, which will open the calibrate screen
• Exit out of the scale import and reference card which appears on this screen.

Step 2

• To import your map image go to the top left-hand side of the screen and click on the yellow folder (Browse).
• Browse for the location and image you wish to import
• Click on the Open button 
• E.g. if your map image is in the Documents folder, select your C/drive > Documents and browse for your map image

Step 3

• If the file you are importing is a '.tif' file, continue to step 4 for calibration.
• If the file is a '.bmp (bitmap)' file, refer to step 5. 

Step 4

• To calibrate your image, select the 'Auto' option under 'Choose Coordinate System'.
• Select a coordiante set for 'Point A' and the opposite set for 'Point B'.
• Once the coordinates are selected, select the 'OK' button. This will redirect you to the home page to begin use.

Step 5

• To calibrate an image, select two easily defined points on the imported image. 
• Note: Two easily defined points might be a road intersection, a shed, large dam. The more accurate these points are the more accurately your map will be calibrated. 
• Follow the steps below to complete calibration.
• You will need to locate the following icons on the toolbar for calibration:

Note: Holding down shift and zoom will allow you to zoom out

Step 6

• Define point A.
• Zoom into point A using the icon (located top left of screen)
• Click the (A) icon in tool bar.
• Click map on exact spot where A would be.

Step 7

• Cancel the zoom (click the cancel zoom icon located on tool bar).
• Repeat step 4 for Point B

Step 8

• On the right hand side of the screen, select the Decimal, D.M.S tab or Map Grid Ref.
• Enter coordinate information in space provided.
• Note: Google Earth Pro or Google Maps are a source of getting your coordinates but are not recommended by Practical Systems as they are generally not accurate enough.
• Do not enter your Latitude as a negative amount. 

Step 9

• Once you have entered the latitude and longitude for each point, click on the OK button
• During the calibration process, your map should not rotate any more than 5 degrees. In this case, check your working again and make sure the latitude and longitude are correct for each point. You may need to start again and select two more points. Phone Practical Systems if you require assistance with this.

Step 10

• Select Yes in the following messages that will pop up, providing it states that the calibrations will rotate the image less than 5 degrees.