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Pineapple Plantation

Photogrammetry Dramatically Increases Lifetime of Worlds Largest Pineapple Plantation | QuestUAV News

UAV Image Interpretation Dramatically Increases the Lifetime of the World’s Largest Pineapple Plantation

Soil Erosion Reduced by a Factor of Almost Thirty, Ensuring Fruit Cultivation for the Next 100 Years

Key Achievements

Scientific photographs taken from Unmanned Aerial Vehicles, like the QuestUAV Agri-Pro system, and processed with Pix4D are a powerful tool to fight soil erosion. Our case study shows that image-based farm management can significantly reduce the soil loss on tropical fruit plantations, such as pineapple. In our study a reduction from intolerable 200 t/ha/yr was reduced to tolerable soil loss levels of ; a factor of 27 times improvement. The management at Dole Philippines were both surprised and delighted by the effectiveness of the UAV derived plans.

Soil Erosion

Soil erosion is considered to pose a major threat for pineapple production and environmental preservation in the Philippines. Soil loss rates vary with rainfall, elevation, slope gradient and soil characteristics and can reach up to 250 t/ha/yr. Based on experimental results, those losses can decrease potential yields as much as 30% in one crop cycle. Fighting soil erosion is therefore a major objective to move to a sustainable cultivation of pineapple in the Philippines.

Unmanned Aerial Vehicles (UAVs) combined with know-how in farm management provide new opportunities to significantly reduce soil erosion. Digital Elevation Models (DEMs) gained from UAVs are the basis for designing relief-adapted field layouts (planting rows, drainage channels) and an effective placement of soil conservation structures.

 

Project Scope

Our study was carried out on the world’s largest pineapple plantation, managed by Dole Philippines Inc. and located at the footslopes of a volcanic cone on the island Mindanao. The area has a total size of 220 sqkm and a strong relief.

 Dole Inc Survey DroneDole Inc SurveyingDole Inc Drone Launch                                                       

Since March 2014 Dole Philippines has been flying their fields on a daily basis with two QuestUAV Agri-Pros. The Quest UAV “Agri-Pro” carries a Twin NDVI sensor providing Dole Philippines with RGB and NIR information at a spatial resolution of 5 cm. The images are the basis for designing and implementing new relief-adapted field layouts and soil conservation structures. The whole implementation workflow was developed by Dole Philippines in close cooperation with the German company ORCA Geo Services (GIS and agricultural consulting) and QuestUAV.

Dole Philippines, as a leading agricultural company in the Philippines, has an excellent environmental protection policy for its agricultural production. Soil erosion is continuously measured and analysed over time, allowing comparisons between soil loss rates of old and new, relief-adapted field layouts.

Results and Conclusions

The graphic below shows how the old field layout has been adapted to the relief on the basis of a Natural Color Image and a Digital Elevation Model (DEM). The total area of the field is 85 hectares. The images were acquired with the QuestUAV Agri-Pro System. The image processing was performed with Pix4Dmapper Pro. QGIS was used to design the new field layout.

Digital Elevation Model Pineapple PlantationThe old field layout shows that planting contours do not follow the contour of the terrain. In some parts of the field, planting blocks are oriented perpendicular to the contour and rain events have a massive erosive effect. Water masses will flow directly downslope transporting huge amounts of soil material. A soil loss rate of 200 t/ha/yr was measured for the steep-slope parts of the field.

Contour lines were calculated on the basis of the DEM. Contour lines indicate the ideal shape and orientation of planting rows. Ideal planting contours would follow curves rather than straight blocks. As curved planting rows are not practical for large field machinery, a compromise was required. The field has been divided into two regions with different block orientations.

After the layout design was implemented in the field, new UAV images were taken. The updated image product shows how the block orientation has been changed according to the design. A direct downslope flow of water is hindered by the pineapple plants. By only changing the block orientation, the soil loss rate was reduced significantly from 200 t/ha/yr to 13 t/ha/yr.

Dole Philippines is planning to install additional soil conservation structures to reduce the soil rate further to . Their conservation programme includes, amongst others, mulching, the protection of receptor and tributary channels, the construction of sediment catching ponds and a special conservation strategy for gullies.


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Fixed Wing vs Rotary Image 1

Fixed Wing Versus Rotary Wing For UAV Mapping Applications

Fixed Wing Versus Rotary Wing For UAV Mapping Applications

Fixed Wing vs Rotary
UAVs (also known as drones) come in many shapes and sizes. Each of these have their own unique pros and cons. It is these characteristics which ultimately leads to the operator's decision in which platform will best fit the application. It is understanding these key attributes and acting on them will ensure that your mapping mission is a success.

Fixed Wing Or Rotary Wing UAV?
UAV aircraft currently boil down to two categories, fixed wing and rotary wing. As you may have guessed each of these categories can be further broken down, for example a fixed wing UAV can be high wing, mid wing, low wing and flying wing, again each having their own unique characteristic advantages and disadvantages. For the purposes of this article we will be focusing on the “top level” differences between the two.

Fixed Wing UAV
Fixed Wing vs RotaryFixed wing UAVs, such as the Q200 and DATAhawk, consists of a rigid wing that has a predetermined airfoil (again another variable) which make flight capable by generating lift caused by the UAV’s forward airspeed. This airspeed is generated by forward thrust usually by the means of a propeller being turned by an internal combustion engine or electric motor.

Control of the UAV comes from control surfaces built into the wing itself, these traditionally consist of ailerons an elevator and a rudder. They allow the UAV to freely rotate around three axes that are perpendicular to each other and intersect at the UAV’s center of gravity. The elevator controlling the Pitch (Lateral axis), ailerons controlling the Roll (Longitudinal axis) and the rudder controlling the Yaw (Vertical axis).

Fixed Wing vs RotaryThe main advantage of a fixed wing UAV is that it consists of a much simpler structure in comparison to a rotary wing. The simpler structure provides a less complicated maintenance and repair process thus allowing the user more operational time at a lower cost. More importantly the simple structure ensures more efficient aerodynamics that provide the advantage of longer flight durations at higher speeds thus enabling larger survey areas per given flight.

Another advantage of fixed wing UAVs is that the flght characteristics due to their natural gliding capabilities with no power.

Also worth considering is the fact that fixed-wing aircraft are also able to carry greater payloads for longer distances on less power allowing you to carry some of the bigger (more expensive) sensors as well as twin sensor configurations.

The only disadvantages to a fixed wing solution is the need for a runway or launcher for takeoff and landing however VTOL (vertical take off/landing) and STOL (short take off/landing) solutions are very popular to help eradicate this issue. Also fixed wing aircraft require air moving over their wings to generate lift, they must stay in a constant forward motion, which means they can’t stay stationary the same way a rotary wing UAV can. This means fixed wing solutions are not best suited for stationary applications like inspection work.

Rotary Wing UAV
Fixed Wing vs RotaryRotary wing UAVs consist of 2 or 3 rotor blades that revolve around a fixed mast, this is known as a rotor. Rotary wing UAVs also come in wide range of setups consisting of a minimum of one rotor (helicopter), 3 rotors (tricopter), 4 rotors (quadcopter), 6 rotor (hexacopter), 8 rotors (octocopter) as well as more unusual setups like 12 and 16 rotors! Like fixed wing solutions, these setups can be further broken down, for example a Y6 setup consists of a tricopter with twin rotors on each arm, one pointing upwards and one pointing downwards and an X8 consists of a quadcopter with twin motors on each arm. Again each setup has their own unique characteristic advantages and disadvantages.

Rotor blades work exactly the same way as a fixed wing, however constant aircraft forward movement is not needed to produce airflow over the blades, instead the blades themselves are in constant movement which produce the required airflow over their airfoil to generate lift.

Fixed Wing vs RotaryControl of rotary UAVs comes from the variation in thrust and torque from it’s rotors. For example a quadcopter’s downward pitch is generated from the rear rotors producing more thrust than the rotors in the front, this enables the rear of the quadcopter to raise higher than the front thus producing a nose down attitude. Yaw movement uses the rotor’s torque force where diagonal rotors either spool more or less than their counter diagonal rotors thus producing an imbalance in the Yaw axis causing the quadcopter to rotate on the vertical axis.

Tricopters are the only exception to this where their rear rotor requires a servo to physically move the rotor to vector it’s thrust rather than using the rotor’s torque to enable vertical axis control.

The biggest advantage of rotary UAVs is the ability for takeoff and land vertically. This allows the user to operate with in a smaller vicinity with no substantial landing/take off area required. Their capacity to hover and perform agile manoeuvring makes rotary wing UAVs well suited to applications like inspections where precision manoeuvring and the ability to maintain a visual on a single target for extended periods of time is required.

On the flip side rotary wing aircraft involve greater mechanical and electronic complexity which translates generally to more complicated maintenance and repair processes thus meaning the user’s operational time can be decreased, which can occur increases in operational costs.

Finally, due to their lower speeds and shorter flight ranges the operator will require many additional flights to survey any significant areas, another increase in time and operational costs.


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