Utilizing a DJI Airframe and Datugram3D software, a beautiful cultural site was easily and accurately mapped at a fraction of the cost of traditional methods.
DJI Spreading Wings S1000
City of Jerusalem
When Israeli authorities made the decision to open up one of Jerusalem’s heritage sites to the public, the 80,000 square meter area first needed to be thoroughly mapped to aid in future restoration efforts. As opening the site was a government priority, the surveying firm would need to finish mapping the area in just 90 days and at a competitive price.
The company winning the bid to map the site compared traditional processes with a UAV-based approach that leveraged DJI airframes and Datumate’s Datugram3D software. This significantly more efficient and cost-effective approach was able to complete the project in time while costing 7 times less than using solely total stations and 5 times less than using 3D laser scanners.
As Israeli authorities made the decision to open up the site of an ancient village near Jerusalem of significant historical value for tourism, an accurate map of the site was first needed to in order to be able to restore it in case of damage. The sloped, 80,000 square meter site and all of its 121 ancient buildings was to be mapped with just 90 days before the opening of the site. This included 3D vector models of each building, together with 2D plans of roofs and facades, in addition to a 1:100 topographic map of the entire area.
A topographic CAD map of the whole site was one of many deliverables generated.
Two traditional on-the-ground solutions – Total Stations and Laser Scanning – were considered but ultimately determined not suitable due to cost and time requirements.
Standing out from the two previous options was a UAV-based solution using DJI airframes and Datumate’s image capture and mapping solution, which was able to meet the deadline and came in at one seventh and one fifth of the cost, respectively, of the two traditional solutions.
The surveying firm prepared a plan during which a survey crew established geo-referenced control points for 10 buildings per week, following which a UAV pilot was brought in to capture the image data for each of the buildings. With the added control points, the accuracy of the captured data was ensured by comparing it to the measurements taken previously on the ground.
Back in the firms’ surveying office, a DatuGram3D worker is geo-referencing the aerial photos for each building using data from the survey crews. Simultaneously, a second DatuGram3D worker is building the facades and 3D model using DatuGram3D software and CAD.
Since this project, DJI and Datumate have strengthened their partnership further by working together to create a fully integrated field-to-plan solution for aerial surveying and mapping. The new solution leverages the easy-to-use DJI Phantom 4 airframe, DatuGram3D mapping software and Datumate’s newly created flight planning software, DatuFly, which lets users plan out flight paths in advance to significantly speed up the image capture process.
Each day, the drone pilot spent a total of 5 hours and 15 minutes on site, performing 15 flight legs of 15 minutes each, with 1.5 hours for flight prep and battery changes. With DatuFly, time required for flight prep and battery management will be drastically shortened thanks to the function that senses when the airframe’s battery is running low, remembers its position on the flight path, and automatically resumes its capture process once it has had its battery changed. In effect, this will make the process even more efficient and cost effective.
The surveying firm was able to export 2D sections of a 3D topographic map.
DatuGram3D software was used to build the 3D model and export directly into AutoCAD.
|Total Stations||3D Laser Scanning||Datumate + DJI Method|
|Men and Equipment Needed|
|Field Survey Crew Days||600||150||42|
|Office Draft Human Days||300||360||150|
|Equipment Needed to Complete in 75 Days||8x Total Stations||
2x 3D Laser Scanners (75 days)
2x Total Stations (75 days)
1xDJI Drone (12 days)
1xTotal Station (30 days)
|Costs of Each Method (based on standard prices in Israel)|
|1 Day of Total Station + Crew||$490||$490|
|1 Day of Laser Scanning + Total Station + Crew||$1 050|
|1 Day of Drone Pilot + Equipment||$490|
|Field Costs (Field Survey Crew Days x Daily Cost)||$294 000||$157 500||$20 580|
|1 Day of Draft Officer||$210||$210|
|1 Day of Professional Officer (Required to handle Laser Scanning data)||$315|
|Office Costs (Office Draft Human Days x Daily Costs)||$63 000||$113 400||$31 500|
|Total Costs||$357 000||$270 900||$52 080|
Surveying the site from the air instead of on the ground was estimated to be an order of magnitude more cost effective. Thanks to Datugram3D, time spent post processing of image data was cut in half compared to the Total Station solution, which would have required 150 man days. While the UAV-based solution was still partially reliant on Total Stations, use was cut down from 8 stations for 75 days, to just 30 days’ worth of station use.
Winning the bid for the mapping project with their offer of $550,000 to deliver the complete map, the cost came in at just $53,000, giving the firm an ROI on their project of 1,100%.
Generated a Variety of Deliverables
Datugram3D directly output a CAD file, allowing for the following models of the historical site:
For Each Building:
- 3D vector model in AutoCAD
- 2D facade plans, including ortho-photos
- 2D roof plans
For the Whole Site:
- Topographic CAD map
- Various 2D sections
3D vector models of each building was created in AutoCAD.
DJI Spreading Wings S1000