Would I like to mapping a non-planar area of 157 hectares with differences of 50 meters at some points (164 feets). I’ve done a plan that is estimated in 47 minutes. I know that a I have to change the battery a few times, but my question is whether to continue the mission, I have to always use the same starting point (lift point) of the drone or not. I ask this because from starting point to the further, are almost 2 km (1.24 miles) away and so I will have connection failures with the remote control.
If I change the starting point to the drone up and the mission is planned todo at 100 meters (328 feets), starting from different bases with different heights, the drone will make photographs to several different heights. Is this a problem to generate the map?
Or should I do this in several separate missions and then submit to process all together?
-If you fly a multiple mission battery, the takeoff point is constant. The whole map is relative to the same point. If you do this route, plan the Above ground altitude for high relative to the tallest point of the map.
-Alternatively, adjusting for elevation means you have a bit higher resolution at the points which would otherwise be lower resolution if a constant Above ground altitude were utilized.
Ultimate it depends on
-Your comfort in the area of interest. Can you safely travel to all areas of the area (mainly thinking of accessibility, or if you’re up in the mountains, feasibility), or would it be better to accept the changes in elevation
and
-Your setup. Do you have enough batteries, etc?
If anyone has feedback on this, please chime in! Would appreciate your insight.
I am wondering this as well. As I am planning to map a large quarry which would benefit from being divided into four separate flights instead of one continuous flight. Would differing takeoff sites result in differing heights based on the takeoff point, if the takeoff point has a different ground elevation?
For example: First flight is set to 70m above ground. Then I move to a different point in the quarry where the ground elevation is different from the first takeoff point, say its 3 meters higher. Would I then need to take this into account, and deduct that off of the flight altitude? So that I would set this to 67m?
How do you suggest measuring out differences in ground heigth? Google maps and working out of height above sea level?
Thanks for your reply. Please see below my thoughts about each proposal.
This is my first plan, to do all the area in one plan only. But the area is big and the farthest point of flight is almost 2km from takeoff point. I’m sure that I will lost connection to drone before reach that point. So, I can’t just to go start point and do it from there, even if I have enough batteries to change and resume the mission. Or it’s possible to configure DroneDeploy to continue the mission even with no connection to the remote controller?
Yes I know the area very well and it’s a small town and it’s safe to travel to all areas. So, I change the takeoff point each time I resume the mission, although these means that I will have some areas with higher resolution from other areas?
I think that other option, is to do multiple small missions and adjust the elevation according to takeoff point. But my problem here is manage and plan the multiple areas to make sure that I will overlap all separated areas and finally upload all the images as one mission only.
I wish that there was a feature to plan multiple missions with different settings in one map view Maybe in the future.
For now it’s a DJI Inspire with 3 batteries but I can charge two batteries at same time while one is doing some flight.
I do this a lot. Breaking down the areas into smaller chunks, and adjusting what needs to be adjusted.Within the DD context and app it’s much easier then doing one large chunk I found. More flexibility.
If the changes in height are not too great it will normally work…most times quite well. It really depends on what kind of area you are doing and the differences in the areas.
Sometimes the software has issues stitching it, and to be fair - the DD software can’t always do it without a headache…sometimes you’ll need to manually stitch them in alternative software.
As @Cordelia said, this works fine. You’ll get a warning if the height of images differs more than 100m. If this is the case make sure you have some kind of intermediate height to assist the stitching - big height differences will cause issues stitching. But you can fly from anywhere - just split up into several maps to cover one larger area, each with different T/O points. (You can fly what / wherever you want and just upload the combined image set to MapEngine and ignore your actual flight plan in the app if you wish.
The biggest issue I have seen doing this, particularly on large maps over several days, is GPS variations and you might need to correct EXIF data to improve accuracy.
Thanks @Cordelia and @rogerpearson.
I have splitted the area into 5 smaller chunks and already have done my mapping. I only missed the option to see all the 5 areas that I have planned in one single map, to check if there are enough overlap between them. But with help of Google Earth I think that I have done a good job.
Doing this mapping I have some suggestions to Drone Deploy. It will be good if there is an option to change the home point to another place, like DJI Go app can do. Because in some areas I moved to the end of mapping area and after drone finish the photos I change the controller to P mode and land by myself. But in one of them, the drone is with low battery and when I was landing we activated the Return-to-Home and I had to kill the DD app to enter in DJI Go app to cancel the return home.
The other problem that I noticed is that DroneDeploy ignores low battery warn during the mission. I understand that low battery warn can be a large piece of minutes but when DroneDeploy cancel the mission because there is not enough battery to complete? It seems that never cancel except when drone automatticaly activates the return-home failsafe. But this is too risky.
I’ve found that if you are running the latest Android (Marshmellow I believe…) and you have DGI GO and the DD app installed on the same device - it causes a lot of problems in flight in terms of how the drone is controlled. I have the GO app on one device and the DD app on another. I’ve found they don’t play nice.
Also, I’ve found that DD will usually send the unit back when it gets to the low batt level - however it’s not constant so you can’t bank on it working every time. At the end of the day, you gotta plan your flights carefully, be realistic about your flight time and take into account wind. Usually for me, if the DD app triggers the warning, the drone is already on the way back to the home point.
If the drone loses contact with the controller, then reconnects - it also tends to have a negative effect on things.
In mapping large areas with DD it would be nice if the first leg remembered the pressure altitude so that on successive legs it would go to the same altitude after you moved to another T/O location to complete the mission.
Having the landing as in the Go App to the controller would be a good feature.
Having the Drone go back to the last photo point instead of the start of the leg would also be a good feature. ( I was on a 2 mile leg and battery ran out before I finished and had to do almost all the last 2 Miles leg again)
Just some thoughts that I think would not be difficult for DD to implement.
I did stay at the Holiday Inn Express last night!
I think the problem is having two apps running at same time. In iOS I have DJI Go App, DD app and some more third-party apps to use with DJI drone but I always kill one app before open the other one.
Having them just installed on the same device creates problems and disables some of the commands the DD app gives to the drone. The two pieces of software fight for control of the tablet USB and DJI GO usually wins. Things like return to home instructions…battery warnings and camera control don’t perform like they should particularly if the drone loses contact with the RC momentiarly and reconnects.
I have undertaken flights of both farms and quarries. The largest farm was 385 acres. I divided it up into 9 flights so that the greatest distance from the home point was < 500m to ensure compliance with my CAA Licence. Once all images loaded sticking it in blocks was fine. On quarries so far the heights have worked themselves out. I guess if you were using Ground Control Points the problem goes away. I hope to move to sing GCP’s but as yet I don’t have enough jobs to warrant the licence cost plus buying a RTK unit to capture the GCP locations/height.
On my recurring projects I am starting to incorperate the cost of having a surveyor come in and set aerial targets on state plane coordinates and elevation. If the site is a recurring flyover project, it helps spread the costnover multiple events and should feally make a difference.
thanks for all the previous information. I have to make a 3d of an area of 3x5km (15km2) and will do it in multiple plans. The question is… how many pictures will I need for this. And which plan do I need? Is a pro plan enough? I think I will have over a few thousand pictures…
Hi @Karin_Brussaard - please do reach out to sales@dronedeploy.com with your inquiry to set up a call with one of our team members. They’ll be able to walk you through each plan and see what would work best for your needs.
Similar problem here. I have about 300 acres of a community to map, will take multiple flights, from multiple launch points.
I don’t know if the core question was answered here, but it sounds like I need to do the following:
Make sure I understand the highest elevation in the area, and plan my flight altitude across the whole region relative to that.
For each individual flight, take into account the difference in ground elevation at the launch point to adjust the flight altitude so that each flight’s altitude is the same, relative to the highest elevation identified in step 1.
If I do that, the 3D elevations will come out relatively ok?
I have a similar problem. I do surveys for coastal erosion studies of bluff that are anywhere from 40’ to 120’ high. I usually have to launch from the top, so I need to set my flying height at about 30-40 feet. I use 85% forward overlap and 65% side overlap for missions over relatively flat ground with great results. ( I have the advantage of having a survey grade RTK-GPS system so I set GCP’s and have coordinates within 0.03’ on them. BTW regular 8.5x11 targets printed on heavy paper work great!)
My probelm is that my overlap gets completely messed up because DD thinks I am flying 30’ above ground and actually I am actually at two or three times that! Figuring out the correct overlap settings is a mathematical exercise I don’t care to repeat too often. I am thinking of using P4D free flight mode to just take pictures at a specific distance.
For your problem and I don’t know what you should do. It never happens to me a similar problem. The pictures should have GPS relative altitude and absolute altitude information. Can you see in Exif if these information is correct?
You should do multiple flights at different altitude in order to GSD (Ground Sampling Distance) will be aproximately constant for the project since the height difference between the UAV and the terrain is maintained.
Maybe in the future.