GPS

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(This function is only available in OCAD Professional!)

  • HDOP: In this field the HDOP (horizontal dilution of precision) is displayed. HDOP is a quality indicator for the position of the useable satellites on the local sky. HDOP values less than 4 are very good, HDOP greater than 8 bad.
  • Precision (x Val): In this field the accuracy (root mean square) of specified number of last measurements is displayed. Filter length can be specified in GPS real time settings.


ADD


Real Time GPS

Choose this command to map with GPS in real time. The GPS box appears lower right. The GPS receiver must be connected to the PC with serial data cable.

hint Important is that the coordinate system on GPS receiver is WGS84 or a UTM zone. If this is not the case, then OCAD cannot analyze the data correctly and the position is wrong (some 100 meters)!
  • Easting: In this field the easting value of the coordinate is displayed. If the filter is activated then it is the averaged value.
  • Northing: In this field the northing value of the coordinate is displayed. If the filter is activated then it is the averaged value.
  • Height: In this field the height is displayed. If the filter is activated then it is the averaged value.
  • DGPS: A green or red dot shows if DGPS signal is received.
  • Satellites: In this field the number of received satellites is displayed.
  • HDOP: In this field the HDOP (horizontal dilution of precision) is displayed. HDOP is a quality indicator for the position of the useable satellites on the local sky. HDOP values less than 4 are very good, HDOP greater than 8 bad.
  • Precision (x Val): In this field the accuracy (root mean square) of specified number of last measurements is displayed. Filter length can be specified in GPS real time settings.


Start GPS Measurement

ADD PICTURE

Click this button to create an OCAD object with GPS. A symbol must be selected. Choose a point symbol to create an object to the GPS marker. If a line or area symbol is selected, OCAD starts with measurement and drawing. The object is represented with a thin black line.

  • Pause GPS Measurement: First click: Interrupt GPS measurement without finishing the object.
Second click: Go on with GPS measurement.
  • Stop GPS Measurement: Click this button to finish the line or area object. The object is displayed with the assigned symbol.
  • Find: Click this button if the GPS marker is not in the drawing windows. The view moves to the GPS marker.
  • Filter: Turn on/off filter. See also: GPS real time settings.
  • Accuracy circle: Turn on/off accuracy circle. See also: GPS real time settings.
  • Point mode:
Choose Normal point option when for every position received from GPS a point should be added to the object.
Choose Corner point option when a position should be manually added to the object by clicking Start GPS Measurement button. This option is typically used to draw objects with straight parts and corners like a fence.
Point mode cannot be changed if a point or text object is selected.
  • Add position to calculate average:
Click this button for every position you want include into average calculation. The number of added positions is shown in the button hint.
Click start GPS measurement button to create the object at the calculated average position
  • Open GPS Real Time Settings: Open the GPS real time settings dialog box.


Real Time GPS Settings

Choose this command to open (activate) a GPS receiver connected to your computer.

Connection settings Port: Choose here the port where the GPS receiver is connected. The GPS receiver must send the NMEA 0183 format. Speed: Choose here the speed of the serial port. NMEA 0183 defines 4800 bps but some receivers may send data at a different speed. Test: Choose this button to see the messages sent by the GPS receiver.

Requirements

  • DGPS: Check this option if you are using DGPS. Positions calculated without DGPS will not be used.
This option has no effect if the receiver does not send the GGA message. Click the Test button to see if your receiver sends a GGA message.
  • Min. 4 satellites: Check this option for better precision. If this option is checked, only positions calculated from 4 or more satellites are used.
This option has no effect if the receiver does not send the GGA message. Click the Test button to see if your receiver sends a GGA message.
  • HDOP: Check this option to define an upper limit for the HDOP value.
  • Otherwise: Specify if received positions should not be saved and/or not be displayed if requirements are not fulfilled.

Options

  • Filter: Check this option to activate a filter and specify how many positions reported by the GPS receiver is averaged. This results in a more stable position, but the update is slower.
  • Accuracy circle: Check this option to show the accuracy circle. This shows the accuracy of the last 5 measurements with a circle around the GPS marker.
  • Auto scroll (moving map): Check this option to move the map automatically with the GPS marker.
  • GPS real time mode: Choose between Geo-referenced mode (like OCAD 9) and Adjusted mode (like OCAD 8).

Coordinate system: Click this button to change the coordinate system. The dialog box Coordinate system appears.

Test GPS dialog box

This dialog box displays the NMEA 0183 signal from the GPS receiver.

Serial data

If the GPS receiver sends GGA messages, those messages are displayed here. Characters 4 to 6 show the abbreviation GGA (e.g. $XXGGA...).
If the receiver does not send GGA messages, then the RMC messages are displayed. Those messages have no information about DGPS and the number of satellites used. However, the position can still be used in OCAD.
If the box remains empty, then the GPS receiver is sending neither of the two messages or there is a connection problem. Check that you have selected the right port in the GPS real time settings dialog box and that the GPS receiver is connected correctly to the PC.

Import Data from GPS Device Choose this command to import data from GPS Garmin eTrex. The GPS receiver must be connected to the PC with serial data cable.

  • GPS: In this field the information about the GPS receiver is displayed.
  • Status: In this field the status between OCAD and GPS is displayed. If the GPS receiver is not connected click the Connect GPS button to connect.
  • Connect GPS: Click this button to connect OCAD with GPS receiver. After successful connection the GPS information and the status are displayed.
  • Settings: Click this button to change the GPS settings. The dialog box Import Data from GPS Device appears.
  • GPS data:
Get waypoint: Click this button to download all waypoints. Each waypoint is displayed with a line in GPS data field.
Get tracks: Click this button to download all tracks. Each track is displayed with a line in GPS data field. Only the start point is displayed.
This command can take serval minutes!
  • OCAD objects:
Set label: Check this option to create also text objects with the name of waypoints and tracks.
CRT: Click this button and choose a cross reference table (*.crt). GPS data can assign to an OCAD object. If no cross reference table is selected then create OCAD unsymbolized objects.
Each line of the cross reference table consists the OCAD symbol number and the Garmin symbol name.
Example of cross reference table:
535.0 waypoint dot
536.0 campground symbol
540.0 scenic area symbol
Create:' Select the waypoints and tracks in GPS data field. Click this button to create OCAD object from the selected GPS data.

hint A popup menu appears when clicking the Right mouse button in GPS data field. You can clear the list, select and unselect records.

Import from File

Choose this command to import a GPS data file to the current map. The Load GPS data from files dialog box is displayed. Initially all importable GPS data files are listed. The following file types can be imported:

GPX files
FRWD files
NMEA files

The waypoints and tracks from the imported file are listed in the Import data from GPS device dialog box.

OCAD objects

  • Set label: Check this option to create also text objects with the name of waypoints and tracks.
  • Assign Symbols: Check this option to assign a specified symbol to the imported objects. Otherwise OCAD will create unsymbolized objects.
  • Create: Select the waypoints and tracks in GPS data field. Click this button to create OCAD object from the selected GPS data.

hint A popup menu appears when clicking the Right mouse button in GPS data field. You can clear the list, select and unselect records.


GPS Import Settings In this dialog box you can make the setting for the GPS data import. Verify also your setting in GPS receiver (e.g. data format: GARMIN)!

  • Port: Choose here the port where the GPS receiver is connected.
  • Speed data import: Choose here the speed of the serial port. Garmin defines 9600 bps.
  • Coordinate system: Click the Change button to select or change the coordinate system. The dialog box Coordinate system appears.

GPS Map Offset This dialog box appears if the GPS coordinate is outside the map.

Coordinate system If you work with GPS you must select a coordinate system. Click the Change button to select or change the coordinate system. The dialog box Coordinate system appears.
Offset Choose here whether you want to change the OCAD real world coordinates or to keep the existing ones.
New offset: Choose this option if no real world coordinates are defined for the map. OCAD already proposes reasonable values. You can leave those unchanged.
Existing offset and angle: Choose this option if the map already has real world coordinates and you want to fit the imported objects to the existing coordinates.



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