Scope of this Guide
This guide is based on the document Automatic Image Acquisition With Scanlink and only describes those aspects of the rooftop antenna capture that differ from a standard tower capture with Scanlink. For additional information (e.g. on safety and risk management, equipment requirements, when to fly, using the in-flight controls, etc.), please refer to the latter.

For Rooftop captures the pilot or spotter is required to be present on the roof during the marking and capture of the mission.   DO NOT Attempt mission without access to rooftop area.

When changing batteries, ensure the drone lands and takes off from the same location as the first launch. There is no way to recenter the mission and account for a different home location.

Implementation Scenarios 

This flight plan should be used when there are multiple installation structures present on a single rooftop site. The example below has two groups of structures.

For locations where a general cell tower has been constructed on a rooftop the standard cell tower mission can be used instead. The pilot or a spotter is still required to be present on the roof during the capture. Ensure all pilot(s) follow the rules given by the governing body (eg. CASA, CAANZ etc)

Capture Components

A rooftop capture mission consists of four components:

1. Roof Capture
2. Equipment Capture
3. [Optional] Panorama Capture
4. [Optional] Orthomosaic Capture

Ensure you confirm whether the optional components are included in your deliverables. 

Roof Capture

This will complete one planar overview component of the roof. 

"Planar Overview" refers to path flown across the roof in a grid pattern. 

This is flown at a horizontal distance of 9m from the roof with a gimbal angle of -45 degrees 

The height is determined by the automated capture height (7m from equipment height/obstacles).

Equipment Capture

This consists of orbits starting few meters below the planar overview and capturing around the Antenna equipment

Panorama and Orthomosaic Capture

These are optional components that will depend on the requirements of the site. Follow the instructions on the mission planner to capture

Expected Mission Visualized

Refer to image below showing all of the components and how a successfully marked mission should look like

Capture Procedure

A Demo recording of this steps can be found on SiteSee's youtube channel.

Planning and flying a mission consists of the following steps:

1. Accept the mission task(s)
2. Start the RC
   1. Set up Obstacle Avoidance on DJI Go
   2. Start the Dronelink app
3. Set camera exposure
4. Mark parameters
5. Capture the mission

These steps are described below in the order they must be performed.

Step 1 - 3

Please see the SiteSee Tower Guide for instructions on accepting the mission and setting the camera settings (Shutter Speed, fstop and ISO).

When setting the camera, ensure the shutter speed has been slightly increased to account for the additional reflection from the roof (e.g. from 1/2000 sec to 1/1250 sec). Note that latest DJI SDK does not support the histogram within the Dronelink app.

Check that the Obstacle Avoidance is on using the DJI Go / Pilot app. Refer to screenshot below for expected set up. Refer to section obstacle avoidance section here for troubleshooting

NOTE: Ensure you close the DJI app properly after set up before moving onto the Dronelink app as only one of them should be open at a time to ensure no errors. Refer here for more information.

Step 4 - Mark parameters

1. Start the task. Tap the 'Get Started' button. The app will guide you through marking the rooftop boundary and the tower locations step by step.

2. Enter a unique mission name for the capture. It is recommended to be related to the capture site/location and/or the SiteSee job number. The date (DD.MM.YYYY) is automatically appended to the mission name when generated.

3. Orthomosaic Component Requirement. Select if an Orthomosaic component is required to be complete at the site.

4. Panorama Component Requirement. Select if a Panorama component is required to be completed at the site.

Add Components. 

Select what component to mark. Select Tower to add tower points, Obstacle to mark an obstacle. The Panorama and Orthomosaic components options will be visible only if they were selected as required. Select Planar Step when all towers and obstacles are marked. Select Next to move onto the next stage of marking. 

5. Add Tower Component. (NOTE: The word "Tower" is used interchangeably with the word "Antenna" and/or "Equipment"). "Tower" can also include an equipment clusters present. 

The order the towers are marked will be the order it will complete them during the mission. 

The Default Component Options with no Panorama and Orthomosaic requirements

Drop down list if Panorama and/or Orthomosaic components are required

5.1.Tower - Mark the Equipment (Tower/Antenna) Height. With the gimbal at 0 degrees, fly to the top of the tower structure or equipment and mark the height. In many situations the height will be the top of the equipment panel. 

5.2.Tower - Mark the Equipment (Tower/Antenna) Center. Fly above the tower, with the gimbal at -90 degrees, mark the center of the tower.

5.3.Tower - Mark the Equipment (Tower/Antenna) Radius. With the gimbal at -90 degrees, mark the radius of the tower. For small equipment/structures this may be very similar to the tower center with very little difference.

NOTE: When to use individual antenna marking vs clustering antennas. 

Example 1: Yeronga Rooftop - Mark only one antenna orbit - Clustering

Note that the 4G and 5G panel are separated by a very short distance <1m therefore not needed to mark two antenna orbits here doing that would cause excessive overlap as 2 equipment orbits <1m apart would essentially be the same images

Instead just pick the center of these 2 pieces of equipment as per the image and mark that

Example 2: Yeronga Rooftop - Mark separate antenna orbits

The equipment is separated by a large distance. Separate antenna orbits need to be marked here

Example 3: Forest Hill Rooftop - Ambiguous antenna orbits 
On this rooftop there are multiple antennas on either side.  This pilot here has done the right thing by group into two clusters and marking it. This ensures that enough detail is captured to view/reconstruct the back of the antennas but not so many images that it causes excessive overlap affecting the reconstruction negatively  

6. Add Obstacles. Mark obstacles on the roof to be avoided. The order of the obstacles are not important.

6.1.Obstacle - Mark Obstacle Height. With the gimbal at -90 degrees, fly above the highest point of the obstacle and mark the height.

6.2.Obstacle - Mark Obstacle Boundary. With the gimbal at -90 degrees, mark the boundary of the obstacle. Create a circle boundary by marking two points, the center and the radius or for a polygon boundary mark more than three points of the outer edge area.These are marked with the same technique as a tower Mission.The example has 4 polygon points marked. 

Repeat for additional obstacles. Do not mark the building or the towers. Obstacles can include anything external around the perimeter of the rooftop that may obstruct the planar overview components or internal on the roof area that may obstruct the transition between components.

7.1.Panorama - Mark the Panorama Height. With the gimbal at 0 degrees, fly up and mark the highest point of the point of interest. This is typically the Tower on site or the center of the rooftop. The panorama will be completed on this marked point. In the example the marked point is 30m high. 

7.2.Panorama - Mark the Panorama Center. With the gimbal at -90 degrees, fly up and mark the center of the point of interest. This is where the panorama will be completed.

8.1.Orthomosaic - Mark the Highest Point. With the gimbal at 0 degrees, fly to the highest point in the area and mark the height. Typically this will be the top of the tower or obstacle in the area. in the example the highest point is 30m high. The orthomosaic will be complete on this marked point.  

9. Mark Planar Overview Boundary. With the gimbal set to -90 degrees, fly above the roof height and mark the edges of the building. Mark the points in a clockwise or anti-clockwise direction. Ensure you mark the lowest possible number of points see additional information below. The example has 5 points marked.

Mark points in either direction 

If the points are not marked in the correct order (either direction is fine - it just has to be consecutive) then the mission will generate an incorrect flight path. See below:

Marking different points of the building.

As opposed to the previous version where the marked points had to only be the external corners of the building this mission version can have points marked in internal and external edges

10. Planar Overview Height (Auto calculated). 

If Towers and/or Obstacles are marked the mission planner will auto calculate and suggest a value for the planar height. The pilot does not need to confirm this - it will automatically be added to the plan.

11.0 Review the parameters. Review the selected parameters and tap continue to generate the flight plan.

The mission flight plan will fail to generate if an equipment orbit is set above the planar overview height, if this happens, go back and decrease the specific equipment orbit height or increase the planar overview height. It will also fail and warn the user if the Panorama and/or Orthomosaic component is selected but the required parameters have not been marked. If this happens go back and add the required parameters.

12.0 Review Flight plan. Review the generated flight plan. In the example, three different tower/equipment structures have been identified and marked. Check the 3D flight plan and the transition between components to minimise the possibility of an obstacle collision.

Red: Marked Obstacle Area

Blue: Marked Building

Green: Marked Tower/Equipment

2D Mission View - Flight Path view in 2D with marked restricted zones

With-out Panorama and Orthomosaic components	With Panorama and Orthomosaic Component

3D Mission View - Restricted Areas and Flight Path view in 3D.

With-out Panorama and Orthomosaic components	With Panorama and Orthomosaic Component

Example marking for various use cases

Key for identifying components in diagram below as follows, 

BUILDING

EQUIPMENT

OBSTACLE NON-ENVELOPED

OBSTACLE ENVELOPED

Use case 1: 2x Equipment Cluster. Same Height. No obstacles

Use case 2: 2x Equipment Cluster. Different Height. No obstacles

Use case 3: 2x Enveloped Obstacle , 1x Non-enveloped Obstacle next door. 

Use case 4: No Obstacle/Equipment. Pilot just wants roof

Use case 5: Incompatible Mission Parameters

Step 5 Capture Mission

Start the mission as normal, the inflight controls can still be used if needed to make small adjustments in flight. See tower capture instructions for more details.

When changing batteries, ensure the drone lands and takes off from the same location as the first launch. There is no way to recenter the mission and account for a different home location.

For Rooftop captures the pilot or spotter is required to be present on the roof during the marking and capture of the mission.   DO NOT Attempt mission without access to rooftop area.

 

 

Frequently Asked Questions

What is the direction and height of the orthomosaic?

Direction: This is determined by the start and end points marked, given two points 1 and 2, the ortho will be flown perpendicular to the marked direction. 

Height: When a height is not set for the ortho component a default value of 40m will be used, otherwise it will be the height marked.

  

How do I know if I am marking the boundary points for the roof correctly?

The minimum possible number of boundary points should be marked as the shape of boundary points marked affects the direction and size of ortho. Ensure you refer to the illustrated images in Capture Procedure Step 4, List item 3. Mark Planar Overview Boundary

 

How do I mark the orthomosaic such that it doesn't overlap with a very tall building that can't be marked as an obstacle?

This will depend on how the pilot marks the boundary points. As mentioned in the above FAQ the start/end points will determine the direction.

A suggestion for the pilot is to mark these points such that the drone will be closer to the building towards the last portion of the capture. This will allow the pilot to conduct the mission safely and even abort if necessary (at pilot's discretion) and minimal amount of data will be missed out on.

 

What is the difference between the different versions of the rooftop capture and how do I know which one i'm using?

To know the version number of the capture that you are using, check the version of the mission contact SiteSee Support.

SiteSee aims to constantly improve upon the mission planner that is used.


 

Release Notes: Version 9.8.0

• Planar boundary extends uniformly across all shapes (instead of radial expansion).

• Certain rooftops had excessive image count on Planar boundary. This has now been rectified

• Orthomosaic marking has validation. Historically pilots have made some mistakes where the ortho was marked at a very low height this has now been rectified where if the ortho is too low if will throw an error instructing pilots to mark it higher

 

Release Notes: Version 9.7.0

• Number of images decreased. This means

  • less time on site due to lower number of assets captured

  • less storage required

  • less time taken for upload

• Increased Drone speed

  • increased by 2 times during the roof capture

  • increased by 2 times during the orbit capture

    • Needs the capture interval to be kept at 1s to capture same num of images at faster speed

• Less complex marking parameters required

  • Planar height has auto calculate

  • No more mid equipment heights

  • No more MSA marking

  • Roof can be marked in clockwise OR anti-clockwise direction

  • Points on rooftop not limited to external edges

• More control provided to the pilot during mission marking. SiteSee no longer adds offsets or clearance logic for the following components.

  • Panorama and Orthomosaic heights

• The issues with marking the facades in urban areas where buildings are nearby is fixed with the planar overview as it only extends less than the previous mission version

• Less likelihood of drone getting “stuck” on multi roof level flight as there are minimal orbits

New version (v9.6.0)	Old version (v8.6.1)

 

 

Release Notes: Version 8.6.1 

• Removed the marking of “Equipment Overview Level“ and pilot no longer needed to calculate and ensure there is overlap with Facade
• Pilot only marks Equipment Height. Extra orbits added by mission planner. These extra orbits,
  • start 3m above Equipment Height instead of old value (4m),
  • orbits are spaced 3m apart
  • the lowest Equipment height orbit is -30 to help tie the -10 better
  • the remaining Equipment height orbits are -45
• Explicitly stating focus to be on manual mode. (Ensures that it will be the value we want no matter what Dronelink makes the default value to be)
• Restructure the order that equipment orbits are flown so done from highest to lowest therefore making mission faster and conserving more battery

 

Release Notes: Version 8.4.0

• Includes a check where the Tower Overview has to be marked around 4m from the Tower Height to ensure that the Tower Overview Level overlaps with the Lowest Height of the Facade

Release Notes: Version 8.3.0

• Camera settings (automatically set the gimbal to the correct angles)
• Better descriptions for marking

 

Release Notes: Version 8.2.0

• There are 4 Facade's being captured now which ensures better capture quality
• The number of images captured has been increased  

 

Release Notes: Version 7

• Improves the horizontal overlap in the facade component allowing for more images captured of the roof
• Orthomosaic component was capturing too many images, this has been resolved by reducing the number of images captured. 
• Antenna (individual towers) component
  • Radius of equipment orbit increased
  • Radius/Height of overview orbit increased
  • Includes additional overview level
• Height at which Panorama captured increased 
• Height of Facades raised by 3-5m
• Addressed feedback given by pilots where direction of ortho was to be determined by the pilot
• Addressed issue raised by pilot where drone flew too close to obstacles by increasing the tolerance distance between obstacle and drone trajectory