Creation of a large map
Hello,
I', using a DJI Air 2s and Dronelink to organise the flight route. I will be surveying a large map 10km by 2km in the Sahara, no internet. Further processing with Agisoft Metashape. Currently I still have some questions regarding my project:
Is it possible to follow the drone by car and if the battery needs to be changed the drone will not fly to the starting point but to the drone operator?
I can currently only fly the drone 80m high, this is from my knowledge because I have not registered the drone to me yet, how can I register it?
How does the drone or the programs detect the maximum flight altitude in a country?
What is an ideal flight altitude for mapping? I don't need to see every detail, a topographic map and a 2D map is enough for me in the end.
Wind speeds on site can be significantly higher than the maximum allowed in the technical sheets, what are the worst case scenarios?
Thank you for the support
Comments
10 comments
There would be a lot of issues trying to fly something this large. The biggest issues are the size, batteries needed to complete it, the time to map the area etc. You would need to cut it down to much smaller mapping plans. Winds could be an issue and cause it to fly off-course and the mission could fail. Maybe someone else can help with the mapping but it seems like you would have many possible problems to contend with on a map this large.
As far as the altitude it depends on the laws in your country. DL does not calculate any laws, altitudes or where you can or cannot fly in any particular country. That’s up to the pilot. Registering or licensing if needed is also up to the pilot. Good luck.
I don't think I would make that your first mapping mission. You may want to really consider doing some small missions to practice on, more like 10-20 hectares. You are wanting to map 2000 hectares. That is HUGE!! For that you need a fixed wing drone, not an Air 2S.
I would be more concerned about the temperature and the cost of 100 batteries. The time of 33 hours is also important. ;))))
Yep. I think we made our point. Not sure if this was a real post or a joke. 🤪
I have 10 batteries, 2 charger and a diesel engine
I'll consider that, Dronelink mapping says if I fly at 200m altitude I need an hour flight time, if I fly in 80m I need I need 2h. Idk what makes more sense related to the quality. My goal is to map it and get a more or less acurate elevation map. Maybe Dronelink is not designed for areas like this related to time estimation?
I tried with up to 60km/h gusts. I asume permanent wind speed of 30 to 40 km/h. Isn't the drone able to get back to the fly mission? Temperature is max 35° (The drone is possible to fly till 40°)
I'm flying in Mauritania, somewhere deep in the desert. I don't think there is a restriction. How can I registere or unlock the drone?
I already did smaller missions
Why?
No, It is not a joke. I will try it. If it works I'm happy - if not I learnd something. Btw. I'm not a spy. Thanks a lot for you reply! I work for a small renewable energy company.
You need to be using Starter or Growth, not Elite (a hobbyist plan).
Since the question is legit, I will ask a few questions
1. What is the purpose in mapping 2000 hectares?
2. What is the ground sampling distance is needed for the end deliverable?
3. What specific deliverables are you trying to product for this 2000 hectares?
4. How are you going to process this large amount of data? (ie local computer, cloud processing, etc)
5. If processing locally, what is the specs of your PC and how many images are you going to process per batch.?
6. How will you merge all of the sub-sets together?
I will just be honest and say that mapping this size of earth would be challenging for an experienced mapper with the right tools. I am not being disrespectful when I say that making this your first mapping mission has about a 1% chance of success. In order to to do this you would have already have to know all of the answers you asked above. So I don't want to discourage you, but rather encourage you to be start out with small jobs. It would be best to simply go out and map 5 hectares fully and see how it turns out. See if you can accurately create the deliverables (files to the customer) that you need for the 2000 hectares. If you can go out and repeatedly create accurate maps and deliverables for 5, 10, 50, and 100 hectares, now you can attempt the 2000 hectares.
Making a 2000 hectare job your first mission would be like making this your first jump:
https://www.youtube.com/watch?v=Oq08SdoYXgw
“I'm flying in Mauritania, somewhere deep in the desert. I don't think there is a restriction. How can I registere or unlock the drone?”
As I stated, Its up to you, the pilot to find out the laws where you are. Dronelink does not register or have anything to do with the laws of a country.
A lot of other great comments there to consider about trying this large off a plan. I made a 1 square mile normal pattern map, not grid pattern map and it would take about 3 hours, so about 10 or more batteries. That means about 60 or more batteries total and about 18 hours or more. You could not charge the batteries fast enough since it will take about 1-1/2 hours per battery or more. The Different Lighting, winds and the time would mean it’s not really meant to be used this way. Just my opinion though. Good luck.
I am sure that any battery at an ambient temperature of 35 degrees Celsius will end its life during the flight, taking the drone with it. Batteries get very hot at 20 degrees Celsius, let alone in the Sahara desert.
Here is some information about temperatures and effects on batteries:
https://forum.dji.com/forum.php?mod=viewthread&tid=245900
Because of the size - fixed wing drones, even human carrying aircraft, can cover a LOT more ground reliably in a shorter period. Average 4 rotor drones fly at <20mph for approximately 30 minutes, whereas fixed wing drones (VTOL included) fly at 50-100+mph for 60 to 120 minutes, real planes at 150mph+ for 6+ hours: exponential impacts on coverage area, number of pictures, batteries used, etc. Rotor drones cost US250 (DJI mini's) to $5k+, fixed wing from $5k to $50k+ not mentioning operating costs...
Ideally I would like to map 23500 hectares (70000 acres) in a single day at 1cm/pixel resolution - not even fixed wing planes can do that (got quotes for $20k+ and 4-6 weeks), and satellites struggle to get clear images at best 30cm/pixel (soon maybe 15) but also expensive... With my DJI Mini SE current estimates are closer to a century :-) But we can all hope...
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