Carlson RoadNET: Road Profile Editor

Lesson 3: Carlson RoadNET: Road Profile Editor

The Input-Edit Road Profile Editor is accessible from the Edit Road Dialog box.

RP1

Pick “Edit” to Access the Input-Edit Road Profile Editor

In Carlson’s Road Network feature, the initial design Profile is automatically generated and has only a starting and ending PVI – with the elevation at both ends tying into existing ground. The crosshairs are locked to the design Profile.

The initial PVIs can be seen in the profile-grid-view where the existing ground Profile is shown in red and the design Profile in white. The initial PVIs are shown in the table-view with the “PVI Description” indicating the PVI elevation is tied to the “TARGET-SURFACE” (existing ground).

The buttons and settings directly below the profile-grid-view allow the user to edit the Profile and adjust the Zoom and Scale factors of the profile-grid-view. The Insert PVIRemove PVI and Screen Pick PVI buttons at the bottom of the dialog box allow the user to make changes to the Profile using the table-view.

RP2

The profile-grid-view provides the user with a dynamic viewer and editor. As the crosshairs move along the design Profile, a “station” symbol on the drawing screen indicates the corresponding position/station along the Centerline. Also, as the crosshairs move along the Profile, the current Station, Elevation, Slope and Depth (between design and existing ground Profiles) are displayed and dynamically updated at the top of the window. The starting and ending stations for the Centerline are displayed above the buttons at the bottom of the window.

RP3

Input-Edit Road Profile Editor with Station Indicator in Drawing

RP4PanZoom and Zoom Extents: Use these buttons to change the Zoom factor in the profile-grid-view.

RP5Add PVI: Use this button to “screen pick” the location for a new PVI in the profile-grid-view. After screen picking the new PVI location, the New PVI box prompts the user to provide additional design criteria to set the new PVI.

RP6

New PVI Dialog Box

RP7Edit PVI and PVI Edit Mode: Use the Edit PVI button to change the elevation and station of a PVI in the profile-grid-view by dragging-and-dropping it to a new location. The default PVI Edit Mode is “Free” which allows 360-degree motion when dragging-and-dropping the PVI. Other PVI Edit Mode options are: Hold Slope InHold Slope OutHold Station and Hold Elevation. The user also can choose to Hold Vertical Curve LengthHold K-Value or Hold Sight Distance when editing the PVI using drag-and-drop. This setting is controlled in the Road Profile Settings dialog box.

Vertical Exag: Use this setting to “Fit” the Profile into the profile-grid-view area of the window or use other pre-defined options such as “x1”, “x2”, “x5” and “x10” to exaggerate the vertical scale by 1-, 2-, 5- or 10-times.
Sag-Crest Points: After adding one or more vertical curves to the design Profile, a list of the “sag” and “crest” points along the Profile will be listed in the drop-down box.
Through Point: After selecting a PVI in the table-view, pick this button to force a sag or crest point to a specific station and elevation.
Check Station: To find the precise Elevation, Slope and Reference Elevation (existing ground) for a specific station, enter the station in the text box andpress Enter.
Insert PVI: Before picking the Insert PVI button, the user must use the mouse to select/highlight a cell in the profile table-view. Then, picking the Insert PVI button will create a blank row, above the selected row, allowing the user to enter the information for the new PVI.
Remove PVI: Before picking the Remove PVI button, the user must use the mouse to select/highlight a cell in the row corresponding to the PVI to be removed. Then, picking the Remove PVI button will delete the selected row/PVI from the Profile.
Screen Pick PVI: Picking this button allows the user to change the station of a PVI by screen picking a location in the drawing. Before picking theScreen Pick PVI button, the user must use the mouse to select/highlight a cell in the corresponding row of the PVI to be changed. Then, picking theScreen Pick PVI button changes the user to the active drawing screen, prompting the user to “Pick PVI Point:” in the drawing area.
Show Sections: This option is only available if the Template (.TPL) file for the Road has already been specified in the Edit Roads dialog box. When picked, the Show Sections button will open a “Road Design Section Data” viewer window while keeping the “Road Profile” window open as well. This provides the user a dynamic design environment in which the plan-, profile- and section-views are visible at one time. Additionally, when the “Section” viewer window is open, the notes at the top of the profile-grid-view include the “Cut” and “Fill” end-area at the current station along with the “Cut” and “Fill” volume for the entire Road. These calculations are dynamic and will update if changes are made to the design Profile. Use the Specific Station to check the section at a station. Or move the cursor in the profile preview graphic to change the section station.

Road Profile View and Section Viewer with Station Indicator in Drawing

Translate: Picking this button will display the Translate Profile dialog box and allows the user to change the elevation of the entire Profile or a range of stations along the Profile.

RP9

Save: This button saves changes to the Profile (.PRO) file.
Exit: This button exits the Input-Edit Road Profile editor dialog box.
Undo: This button will undo the last change made to the Profile.
Setup: This button opens the Road Profile Settings dialog box. See below for more information.
Vertical Speed Tables: Use this button to specify the Vertical Curve Speed Table (.VST) files to use for the design of this Road.

Road Profile Settings

RP10

Road Profile Settings Dialog Box

Reference CL File: In the Road Network feature, the “Reference CL File” is automatically set to the Centerline (.CL) file associated with the Road.
Hold Current Elevation: When enabled and the station and elevation of a PVI changes, the “Slope Out” of the adjusted PVI will change but the elevation of the next PVI will be left unchanged. Otherwise, if not enabled, the “Slope Out” of the adjusted PVI is held and the elevation of the next PVI is changed.
Grid Ticks Only: When enabled, only grid ticks will be shown in the profile-grid-view. Otherwise grid lines will be used.
Set Grid Interval: If enabled, this option allows the user to manually specify the grid- or grid-tick interval shown in the profile-grid-view.
Show Slope When Zoom In: When enabled, this option allows the user to display the slopes on those vertical tangents that are long enough to display a slope label when Zoom-ing in closer to the Profile.
Show Reference Surface: When enabled, this option displays the Profile of a “Reference Surface” in addition to the design Profile. The “Reference Surface” is typically the original or existing ground Profile.
Show Reference Surface at Left Offset: When enabled, this option allows the user to see an additional Profile that is offset horizontally from the “Reference Centerline”. The offset distance can be specified after the option is enabled.
Show Reference Surface at Right Offset: When enabled, this option allows the user to see an additional Profile that is offset horizontally from the “Reference Centerline”. The offset distance can be specified after the option is enabled.
Show Centerline Special Stations: When enabled, critical Centerline stations such as PC, PT, SC, ST, TS and SP are shown in the profile-grid-view.
Show Vertical Lines for Intersections: When enabled, this option will display a vertical line representing the Centerline and Edge of Pavement stations for other Roads in the Road Network.
Show Sag-Crest Points: When enabled, this option displays a marker at the sag and crest points of each vertical curve.
Extend Reference Centerline: When enabled, the user may provide an extended range of stations so as to show Profile data beyond that generated along the associated Centerline (.CL) file. For instance, for a new Road tying into an existing Road (proposed CL file starts at the Intersection of the Centerline of the existing Road) an extended range of stations may be desired in order to see the Profile of the cross-slope, curb, ditch and slope across both sides the existing Road.
Output Reference Surface Profile and Suffix: When enabled, this option will generate an existing ground Profile (.PRO) file and allows the user to specify a suffix for the filename. The defaults for this option are set using the Output File Defaults button in the Output Options tab of the Road Network Settings dialog box.
Reference Surface: The “Reference Surface” is an additional surface Profile shown in the profile-grid-view alongside the design Profile. For the Road Network feature, the “Reference Surface” is the surface specified as “Existing Ground” in Road Network Settings dialog box.
Check Road Design Parameters: When enabled, this option will compare the current Road design to an established set of design parameters set in a Road Design Parameters (.RDP) file. Please refer to the Help files for the Road Design Parameters command if additional assistance is needed.
Display Sight Distance Options: Use this radio button to display either a “Sight Distance” or “K-Value” column in the profile-table-view.
Drag PVI Options: Use this radio button to specify the design criteria to “hold” when using the Edit/Drag PVI command in the profile-grid-view. The options are to “Hold Vertical Curve Length”, “Hold K-Value” or “Hold Sight Distance”.

Click here to go to Adding and Editing Intersections

Recent Posts

Jam proofing drones

“Collect 1 million data points from a 15-minute flight compared to 300 points in a day from a traditional ground survey. It’s no wonder that drones equipped with GPS technology and remote sensors are revolutionising data collection. But will jamming spoil all the fun?”

Who let the drones out?

Recent years have seen the appearance of affordable, high-end drones which, coupled with easy-to-use mission-planning tools, has created the perfect environment in which drones can flourish. No longer the preserve of specialist drone users, applications using drones have been venturing into areas such as survey, inspection and volume analysis with an impact that is little short of revolutionary.

Interference can spoil it all

In the air, the stakes are higher. When things go wrong, the consequences are invariably much more serious than they would have been on the ground. One of the biggest threats to drone safety is GNSS interference. At the very least, disruptions to satellite signals can degrade position quality causing fall-backs from high-precision RTK and PPP modes to less-precise modes. In the most extreme cases, interference can result in complete loss of signal tracking and positioning.

Self interference

A significant source of interference on UAVs is often the other components installed on the UAV. The restricted space means that the GNSS antenna is often in close proximity to other electrical and electronic systems.

gopro_interference (1)

Figure 1: GoPro Hero 2 camera pick-up monitored by an AsteRx4 receiver

Figure 1 shows what happened to the GPS L1-band spectrum when a GoPro camera was installed on a quadcopter close to the GNSS antenna without sufficient shielding. The three peaks are exactly 24 MHz apart pointing to their being harmonics of a 24 MHz signal: the typical frequency for a MMC/SD logging interface.

An AsteRx4 receiver was used in this setup which includes the AIM+ system. As well as mitigating the effects of interference, AIM+ includes a spectrum plot to view the RF input from the antenna in both time and frequency domains. At the installation stage, being able to view the RF spectrum is an invaluable tool for both identifying the source of interference and determining the effectiveness of measures such as modifying the setup or adding shielding. For the quadcopter installation in this example, the loss of RTK was readily diagnosed and solved by placing the camera in a shielded case while the quadcopter was still in the workshop.

External sources of interference

GNSS receivers on-board UAVs can be particularly vulnerable to external sources of interference, be they intentional or not. In the sky, the signals from jammers can propagate over far longer distances than they would be able to on land.

In the case of UAV inspections of wind turbines for example, many countries encourage windmills to be built next to roads, a situation that increases the chance of interference from in-car chirp jammers. These devices though illegal are cheap and can be readily acquired on the internet. Using a chirp jammer, a truck driver can, for example, drive around undetected by the GPS trackers on the truck and car thieves can disable GPS anti-theft devices on stolen vehicles.

External interference: the effect of a chirp jammer on a UAV flight

Although transmitting with a power of around only 10 mW, chirp jammers are powerful enough to knock out GNSS signals in a radius of several hundred metres on land. In the air, the UAV is much more vulnerable as the jamming signals have a far greater reach, unhindered as they are by trees, buildings or other obstacles.

Figure 2 shows how a 10mW chirp jammer can knock out RTK positioning over more than 1 km in a high-end receiver. Even a low-end consumer-grade L1 receiver, being less accurate and thus less sensitive, loses standalone positioning over several hundred metres.

 With AIM+ activated, the AsteRx4 is able to maintain an RTK fix throughout the simulated flight as well as showing no degradation to its position variance. The full details on these simulations can be found in a recent white paper.

Solving interference on UAV systems

A comprehensive approach puts interference considerations at the forefront of receiver design and incorporates it into every stage of signal processing. In the case of the AsteRx4 and AsteRx-m2, the antenna signal is immediately digitised after analogue filtering and automatically cleansed of interference using multiple adaptive filtering stages.

As each interfering signal has its own individual footprint, being able to visualise the RF signal in both time and frequency domains allows drone users to identify sources of self-jamming and adapt their designs accordingly before the drone gets in the air.

When it is in the air, AIM+ is able to mitigate jamming from external sources: a set of configurable notch filters are complemented by an adaptive wideband filter capable of rejecting more complex types of interference such as that from chirp jammers, frequency-hopping signals from DME/TACAN devices as well as high-powered Inmarsat transmitters.

chirp_jammer_interference

Figure 2: RTK position availability for the AsteRx4 with AIM+ activated and a comparable high-end receiver. The low-end receiver tracks L1 only and outputs less-precise standalone positions. A 10mW chirp jammer is located on the ground at position (0,0) as shown.

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