Last flight of the X350 Pro

This is not my drone, I've just used this picture for emphasis, my drone is at the bottom of a winter lake.

Today was a sad day for The Aero Scout, I lost my Walkera X350 Pro in a wetlands lake. The short story is that it splashed down into the middle of the lake, never to be seen again due to a low battery .... the long story is as follows.

I knew this was going to be a challenging mission, the plan was to map a medium sized wetlands lake in Viveash. The area to be mapped was 120,000m2 (nearly 30 acres), a flight of 4.3km with over 160 images to be taken. Not only was it going to test my flight planning skills as I couldn't survey the lake with just one battery, it was going to need two, it was also going to test the post processing for the 3D map. I would need to plan for an overlap of images between the two missions so that the 3D map would be accurate, and I would need to be careful about the amount of time spent in the air because when flying over water there is no safe emergency landing zone. Clearly I hadn't anticipated all of the potential problems.

The last flight of the X350 Pro ended with the drone ditching into the middle of this wetlands.

On the day the flying conditions were less than ideal, it was hot plus we had 25-35km/h winds blowing across the lake. I'd flown the X350 Pro in windier conditions before so I wasn't too concerned, however this lack of understanding of the affect of such wind on a battery would be one of the main contributors to the crash.

In my flight planning I had a 12min flight time, which usually gives me a 3min safety margin. In hindsight, I should have taken more notice of the wind and adjusted the flight time (in the field) to be a few minutes lower, to take into account the extra power that might be used by the drone to compensate for the strong winds and stay on the flight plan it was programmed with.

Flight plan showing the first stage of the mission 

Flight plan showing the second stage of the mission.

Another contributing factor to the crash, I suspect, was that my batteries were getting old and probably didn't hold as much capacity as they used to. This of course would reduce the flight time that drone was capable of flying. Without any kind of telemetry system built into the drone there was no way of knowing that the battery would not last the planned flight time.

I feel either a better instinctive analysis of the flying conditions that day or a more rigorous pre-flight checklist could have prevented this incident. Plus listening to my intuition and cutting the flight short when I felt something was not right would have also helped, all I needed was another 30sec of battery and I would have had the drone over the relative safety of dry land.    

Lessons learnt:

• Take more notice of local conditions on the day of the flight and be prepared to modify flight plan to suit.
• Add new points to my pre-flight checklist to ensure this analysis is done for every flight, regardless of conditions.
• Test battery capacity more often and adjust standard flight time when necessary.
• Where possible, only fly drones that have a bi-directional telemetry link to a ground station to enable real time monitoring of the systems. This will assist the drone pilot in making better decisions during the mission.

So I've had a setback but I'm not down. I'll re-group, learn from this mistake, purchase a new drone that has greater capabilities and safety features and will then continue with my journey. Stay tuned, I'll be back in a few months with more UAV 3D mapping missions.

This has been another 'drone adventure' in aerial surveying, inspection and mapping by The Aero Scout.

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Primary School - 3D Photomesh and Orthomosaic

3D model of a small primary school created with drone imagery

Mission Summary

• Goal: Test 3D mapping for a site with more complex geometry (structures and trees)
• Tech: QR X350 Pro quadcopter drone, SJ 4000 actioncam, Mission Planner, Recap 360
• Conditions: Midday, sunny, nil wind, magpies swooping
• Outcome: A single grid pattern for collecting images does not seem sufficient for such a complex site. 

With my new G-2D gimbal attached to the Walkera QR X350 Pro drone I headed to the local primary school (on a non-school day of course) to test my methodology against a more technical model, one with open flat areas, trees and buildings. I'm expecting to get much better results with the gimbal installed as it keeps the camera facing directly towards the ground, this helps in eliminating poor quality pictures that are taken during a bank or oscillation, which could degrade the quality of the photo alignment.

QR X350 Pro drone plus modified handset and camera ready for 3D mapping mission

As usual I did my flight planning in Mission Planner. The flight is not covering a large area (just under 5 acres) however because the smallest time lapse on the SJ 4000 camera is 5 seconds I need to fly the QR X350 Pro at a slower ground speed to get the correct lapping in the photos. This means I'm using most of my flight time (taking into account adequate safety and landing time) with this small area.

Using the 'grid' function in Mission Planner enables the drone pilot to more accurately prepare a flight plan so that there is optimal photo overlap. You can see from the image below, Mission Planner has predicted how often the photos should be taken and how much overlap that should result in. For this project, I think the vertical overlap was fine however after seeing the results I think the horizontal overlap could have been better.

Flight plan showing predicted image overlaps

The model below is produced using only 'medium' settings in Agisoft Photoscan as that's all my 4 yr old laptop could handle. Also I'd consider the imagery to only be of a medium quality from the SJ 4000 with it's 12Mp sensor, quality is degraded more as the 12Mp are spread over the extremely wide 170 degree lens.

Nevertheless the results I felt were quite good when kept at a reasonably low zoom, if you get in closer you'll find many problems with the shape and accuracy of the model. Apparently, trying to get accurate photogrammetry for surfaces such as water and building roofs is very tough. Also, the quality of the model has been decreased during the upload process to Sketchfab.

See the model uploaded to Sketchfab below.

Primary School by The Aero Scout on Sketchfab

I'm hoping to improve the quality of the final model in future with a tighter grid pattern as well as a cross pattern (grid in both directions) to get more overlap on the images, a higher setting during processing and an optimised model for uploading.

Microsoft ICE had troubles stitching the images together for this project. As yet I'm not sure why this has happened, perhaps too many trees or too many lines on the netball court which confused the algorithms.

Photo stitch produced in Microsoft ICE - didn't seem to work too well, especially around the netball courts

Autodesk Recap 360 really struggled with this project. I tried using the original 'distorted' images from the SJ 4000 camera with it's 170 degree lens AND I also 'de-fished' the images to flatten them out. Neither model was acceptable, extremely low quality and very poor accuracy, see screenshot below.

Autodesk Recap 360 had alot of troubles dealing with this project and the results were very poor.

This has been another 'drone adventure' in aerial surveying, inspection and mapping by The Aero Scout.

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Alkimos Beach - 3D Photomesh and Orthomosaic

3D model of a section of Alkimos beach

Mission Summary

• Goal: Explore environmental mapping applications with a small UAV
• Tech: QR X350 Pro quadcopter drone, SJ 4000 actioncam, Mission Planner, Photoscan
• Conditions: Midday, scattered cloud, gusty winds
• Outcome: I was very happy with both the 3D model and the orthomosaic, flight planning in the field was also an excellent experience. 

I wanted to test creating a 3D mapping model of a coastal dune/beach area. Environmentalists and research groups would use this technology to monitor coastal erosion, or sea levels over time by comparing two or more models of the same strip of beach.

Conditions were tough, the sea breeze was in and the little Walkera QR X350 Pro quadcopter/drone had to deal with 15km/h winds, which it handled very well, plus with the G-2D gimbal stabilising the camera it made little to no impact on the quality of the images taken.

I wasn't sure which part of the beach I'd be surveying so I took my laptop along with Mission Planner into the field and planned my flight onsite. This worked very well as it was great to be able to look for obstacles and choose the most 'appropriate' part of the beach to survey and map rather than guess, which is what I've previously done when flight planning from home.

Mission Planner does a great job at predicting the amount of photos that will be taken and overlap based on the planned height and speed of the drone and the type of camera being used.

Flight planning in the field using Mission Planner

Here is the finished model, produced in Agisoft Photoscan and uploaded to Sketchfab for easy viewing.

Alkimos Beach by The Aero Scout on Sketchfab

Here is a stitched photomosaic produced using Microsoft ICE. You'll see that what it lacks in 3D it more than makes up with it's high resolution. Click on the image and zoom in on details.

This has been another 'drone adventure' in aerial surveying, inspection and mapping by The Aero Scout.

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Small Construction Site - 3D Photomesh and Orthomosaic

Mission Summary

• Goal: Create a basic 3D mapping model and 'stitched image' orthomosaic.
• Tech: QR X350 Pro quadcopter drone, SJ 4000 actioncam, Mission Planner, Recap 360, Photoscan
• Conditions: Morning, sunny wilth nil wind
• Outcome: Whilst I could create a 3D model and an orthomosaic based on the images taken from the drone, the results where only of low/medium quality.

After a long break from mapping missions (12 months) I'm back with a slightly upgraded kit; the G-2D gimbal for the Walkera QR X350 Pro quadcopter/drone should allow me to create better quality orthomosaic and 3D models for UAV mapping.

The first project I thought I'd test the new gear on was a small construction site right next to the large field I usually fly in. I felt it was an excellent first project as the area is clear of objects, I'm familiar with the flying conditions, it's mainly flat with only a couple of topographic features but it still had a couple of small structures, mounds of dirt and equipment that I could test the accuracy of the model with.

As a basic 'ground truthing' exercise you can compare the above image to the model below. You'll see that there is some slightly higher ground to the right, a few trees, plus a couple mounds of dirt that are roughly the height of the construction office. There's also a few perimeter fences around the site office and equipment.

Flight planning was done using Mission Planner, I just love how comprehensive yet intuitive this program is. It has tools to simply draw a polygon around the area you wish to survey, then based on the height you plan to fly and the type of camera you are using it plans the grid pattern that the drone will fly, this gives the best result for overlapping images. It also displays a summary screen showing the size of the area, the expected flight time, number of photos to be taken and much more.

Here is a screen capture of my laptop showing the model generated from the photos. It shows each 'camera location' confirming the overlap that Mission Planner predicted. It also gives the drone pilot other summary information such as the area surveyed, the number of photos to be taken and flight time, very handy for deciding if it will be within safety limits.

The results for the model created in Agisoft Photoscan are not bad. You can see that the terrain has been accurately re-created, for me, the main let down with this model is the quality of the site office and equipment. That said, my laptop can only handle creating a 'medium' quality model so perhaps they would look better if produced on a higher setting.

Small Construction Site by The Aero Scout on Sketchfab

Compare the model above, that was produced using Agisoft Photoscan to the below model produced in Autodesk Recap 360. The Autodesk is easier to use, you simply upload your images to the Recap 360 account and all the processing is done 'in the cloud' however there are very little options and settings that can be changed.

Below is a 'stitched' photomosaic produced in Microsoft ICE, the program takes all the photos and stitches them together to create a large image of the area. The difference with this to the 3D models created is that usually the resolution and detail when zoomed in is much greater. Check it out below by clicking on the image and then zoom in.

This has been another 'drone adventure' in aerial surveying, inspection and mapping by The Aero Scout.

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Lake Ballard - Aerial Filming

Family camping trip to Lake Ballard to see Anthony Gormley's 'Inside Australia' meant that Jas had to take his Walkera QR X350 Pro along to use it for some FPV quadcopter flying and grab some sunset shots .... hope you enjoy. A big 'gday' to Gill and Helen who we met at the lake and shared a wonderful sunset with.

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Quarry - 3D Photomesh

QR X350 Pro and gear ready to create a 3D photomesh of the quarry wall 

This is my latest attempt at creating a 3D photomesh using the QR X350 Pro drone, SJ4000 Actioncam and Autodesk ReCap 360. This one was done in the Gooseberry Hill National Park at Stathams Quarry. 

Flying conditions were tough on the day with plenty of turbulence around the face of the quarry and getting 'still' images was virtually impossible. In this situation a 2D gimbal would have been very handy and I'm sure the captured images would have been of better quality. Another challenge close to the quarry was getting a GPS lock, I had to take the QR X350 Pro out into the middle of the quarry before it could retrieve enough satellites to fly reliably.  

Even though the flying was tough, I am still pleased with the result. The mesh seems quite accurate and has managed to re-create all of the faces of the quarry wall. The results are significantly better than my previous attempt on the pump station. The images are clearer,  seem higher resolution and ReCap has managed to stitch them together more accurately this time. I'm not sure if it was the subject of the mesh (the wall), the lighting conditions or the new camera I'm using.

For the next project I am looking forward to learning how to take the mesh out of Autodesk ReCap 360 and into another program where it can be put to use.

See the results of this photogrammetry mission below;

Looking into the mesh

Camera angles that the mesh was created from

This has been another 'drone adventure' in aerial surveying, inspection and mapping by The Aero Scout.

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Pump Station - 3D Mesh (V2)



QR X350 Pro vantage point on Pump Station photogrammetry mission

Today I returned to the Pump Station to try my luck on another photogrammetry mission. It was overcast so I thought it would make a better day for aerial photos. they certainly were better than the first attempt, much less shadow and sun glare. I was much methodical in taking the photos this time and I followed the quad around the pump station to make sure it was aligned for each shot.

Autodesk ReCap 360 is very easy to use. Follow their guidelines when taking the photos, upload them to site, sit back and wait for the render to finish. You can go back into the interface and manually manipulate the images to realign any that could not be meshed automatically.

That said I feel that I am still only getting 'basic' results. The mesh is very messy under the eaves of the roof and this causes problems with the textures on the walls. I am using the free version of ReCap 360 and it limits the total amount of images it will import for each project to 50. I'm not sure if this is too few (even for a small project like this) or whether I need to persevere with refining my methodology, choosing an easier subject to model and stabilise the camera more.

I'll continue to see what I can do using the free version a little longer before looking at seeing what the paid version can do to improve my results.

See the video of the mission here;




This has been another 'drone adventure' in aerial surveying, inspection and mapping by The Aero Scout.

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Park Ride - Aerial Filming

Park ride with the QR X350 Pro

Again it was a glorious warm winters evening so Stella and I headed to the park. Whilst there, we both enjoyed some riding and aerial filming practice with the QR X350 Pro. See the video here;

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Pump Station - 3D Mesh

Pump Station photo mesh taken created using Autodesk Recap 360

I stumbled across, what I thought would make, a simple photogrammetry project today, a sewage pump station on the outskirts of the local wetlands. The reason I thought it would be easy is that it is a simple shape and it is surrounded by clear space making it easy to fly the Walkera QR X350 Pro around it.

I turned out to be tougher than I thought. For starters getting the quad absolutely stable is a tough job in even the lightest of winds and watching out for the right lighting is also tough, it was a very sunny day and when the camera was facing towards the sun the photos are all under-exposed. The other challenge is understanding when the GoPro will take a picture, I have it set on a 2 second timer so for each placement I have to wait five seconds or so to make sure I have at least one or two good shots in.

I'm yet to get stuck into all of the functions in Autodesk ReCap 360 to be able to 'manually stitch' photos that couldn't be processed etc. For my second attempt I'm pleased with the results.

Anyway, it's all good fun experimenting and slowly getting better. I'll be sure to go back and try again, next time I'll pay more attention to my methodology and the lighting conditions.

Pump Station photogrammetry mission using my QR X350 Pro and GoPro2 (hard mounted) 

This has been another 'drone adventure' in aerial surveying, inspection and mapping by The Aero Scout.

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Sunday @ the Woody - Aerial Filming

QR X350 Pro with hard mounted GoPro 2

Sunday morning flying with the boyz at the Woodbridge flying field.

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Gazebo - 3D Mesh

Autodesk Recap 360 photomesh of the Maylands gazebo

Harry and I popped out for a lunchtime adventure today ..... picnic bag and quad in tow. I spotted a cute little park that had both a playground and a gazebo by the water that I thought would make a nice photogrammetry project. It was a little windy (10knots) and was hard to keep the quad steady, but at least we ended up with a photo mesh. It's only a basic result but it gives me something to work from and hone my skills controlling the quad in order to get well framed shots. Here is my first attempt at photogrammetry using my Walkera QR X350 Pro, GoPro 2 (hard mounted) and Autodesk Recap 360.

QR X350 Pro first photogrammetry - the gazebo  

Harry  stretching up before the big photogrammetry mission

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X350P - GoPro maiden

X350P with GoPro 2 hard mounted

Meet Cam and Russ at Ascot this evening to try out some aerial filming. Cam bought along his GoPro 2 and wasted no time 'sticking' it to the bottom of the Walkera QR X350 Pro. Check out the rookie videographer and the 100% un-stabilised footage of the fun we had below.

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X350P - Mode testing

Testing the different modes on the QR X350 Pro

Tonight was a good night for testing the three different (pre-set) modes on my Walkera QR X350 Pro. The three modes are;

1 - Manual; in this mode it is all up to you to control everything about the quad, pitch, roll, yaw and altitude It's a tricky mode to fly in, however it also gives the operator more freedom as bank angles are not restricted and the speed you can fly the quad is much greater.
2 - Position hold; this is a stabilised mode where you can still fly around however the quad will try to hold altitude and is restricted in it's bank angle and therefore speed, if you let the handset sticks go the quad will auto level. This is excellent for learning to fly or for taking aerial footage.
3 - Return to Land (RTL); flick the switch for this mode and the quad will automatically (all by itself) stop whatever it is doing, hover, climb to a preset height of about 10m and then slowly bring itself back to the location that you first turn it on at, it will then slowly descend and land .... it's amazing to watch!

See video below of the three different modes in action.

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X350P - Sunset takeoff

QR X350 Pro ready for a sunset flight 

It was a gorgeous evening so I just had to get out for a training flight at one of the nearby flying fields. Check out the video below.

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X350P - First flight

I couldn't wait any longer for the weather to clear up or for me to have the time to get to the flying field so I decided to have my first flight in the backyard. Some of the rationale was that if it did try to fly away all by itself at least it would have a good chance of hitting a tree, post or piece of play equipment!

I was quite nervous, but felt I had prepared well enough by watching a bunch of YouTube videos (Thanks Bo @ FPVGuy.com) and reading the Walkera quick start guide a few times.

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New Direction

Walkera QR X350 Pro with Devo 7 handset

After many weeks of frustration trying to get the auto-tuning to work on the Skywalker X5 I decided to take a break from it all. I was not enjoying the constant tweaking/testing cycle and longed for a complete working kit with full APM functions.

I decided to look into a new direction, multicopters and in particular the RTF versions that have just recently entered the market. So I purchased a Walkera QR X350 Pro, because it has a great flight time (25min) and also uses the same flight controller as the Skywalker X5 (APM).

Whilst the quad won't be able to cover the same mapping area as the fixed wing, it's going to be a more flexible platform and allow other styles of mapping/photogrammetry, this I am very excited about.

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