Inertial Measurement Units (IMU)

An Inertial Measurement Unit (IMU) is an electronic device that measures acceleration and rotation that can be used to calculate position and velocity. IMUs are the main component of the inertial navigation systems commonly used in aircraft, unmanned aerial vehicles (UAVs) and other unmanned systems, as well as missiles and even satellites.

Accelerometer

Accelerometers are used to determine the position and orientation of the drone during flight. Accelerometer is used to provide the acceleration force the drone is subjected to in all three axes, X, Y, and Z. It also determines the tilt angle of the drone in a stationary position. If the drone is static in a horizontal position, its X and Y axis will give 0g output, whereas the Z axis will give 1g output. 1g is the gravity that is experienced by every object on Earth. If the drone rotates by 90deg on the X axis, then X and Z will give 0g, and the Y axis will start giving 1g. During the tilt, X, Y, and Z will provide an output between 0 and 1g.

Gyroscope

Gyroscopes are versatile tool for measuring and maintaining orientation. This is especially important for drones that are used for aerial photography, as they need to remain stable and level to capture the best images. Gyroscopes are frequently combined with accelerometers, which measure linear acceleration. These two components work together to give the drone the information it needs to determine its position and orientation in three-dimensional space.

The use of gyroscope technology aids in the maintenance of a stable hover. The gyroscope detects any wayward drifting or wobbling by the drone when there is no input from the pilot. This data is then sent to a controller instructing the drone’s motors to counteract unwanted movements.

Gyroscope sensor detects angular velocity in three axes. So it can detect the angle change rate Pitch, Roll, and Yaw.

Gyroscopes also ensure that drones rotate at the exact angle user controls expect.

Magnetometer

A magnetometer measures a magnetic field’s intensity and direction. It gives data on the magnetic field in three X, Y, and Z. This helps the drone to determine the magnetic North and change its course accordingly. Apart from direction sensing, magnetic sensors can also detect surrounding magnetism and ferro-metals, such as electricity poles, wires, vehicles, other drones, etc., to help avoid an accident.

Barometer

GPS Sensor

GPS technology has been critical in enabling drones to fly autonomous missions. It determines which way the aircraft should move by comparing the actual position of the drone with its targeted position and instructs the drone motors with the appropriate commands.

A drone is outfitted with a GPS receiver that can receive signals from multiple GPS satellites. Depending on the location of the satellite source, the time it takes for the drone’s GPS module to receive the signal will vary. The drone’s location can be determined by triangulating the relative position of the drone from the different GPS satellites. The precision of the location will be determined by the strength of the signal received by the drone’s GPS module and the number of satellites within its range.

What is an SOP?

SOP stands for Standard Operating Procedure. A standard operating procedure is a document that contains step-by-step instructions and guidelines for employees to follow when performing a technical, repetitive process within an organization. SOPs are employed by a number of organizations to guarantee that tasks are carried out consistently, effectively, and with the least chance of error or omission.

1. Drone Agency Registration and Permissions

There is no need to register with IBM for drone survey in mines. Drone Agencies or the lessee can conduct the survey while following all the applicable rules, regulations and guidelines notified by DGCA. Check the Airspace map from the Digital Sky website. The drone airspace map is an interactive map of India that demarcates the red, yellow and green zones across the country.

Green zones are the unrestricted zones where drones can be operated without any permission

Yellow zones are controlled zones and the drone can only be operated after a permission from DGCA.

2. Drone Specification

Drones used for the survey should follow DGCA guidelines and should possess mandatory safety features as notified by DGCA from time to time.

3. Sensor/Camera Specification and output data resolution

5. Survey Area

The survey should cover the entire mining lease area capturing all mining, allied activities and 100m beyond periphery of the mine lease boundary to monitor the environmental impact and ascertaining any excavation therein. The flight path plan and the numbers of flights taken to cover the entire area shall be provided to IBM along with the output data. For leases having common mine boundary, the survey may be limited up to the lease boundary for the sides, the lease shares common boundary with another lease.

7. Drone Survey Time

It is advised to fly the drone in better conditions when the sky is clear and the sun is overhead to minimize the shadows in photographs. Do not fly the drone when it is rainy or windy.

Mission

The primary mission of Indian Bureau of Mines is to promote systematic and scientific development of mineral resources of the country (both onshore and offshore), through regulatory inspections of the mines, approval of mining plans and environment management plans to ensure minimal adverse impact on environment.

It has been proposed to use a combination of digital aerial (Drone and satellite) images to monitor mining activities in the country. In mining, drones have various applications like mine surveying, inventory management, stockpile evaluation etc.

Ministry of Mines has incorporated Rule 34A in the Mineral Conservation and Development Rules 2017 for submission of digital aerial images of mining lease areas to Indian Bureau of Mines

What is MCDR?

The MCDR have been framed under section 18 of the Mines and Minerals (Development and Regulation) Act, 1957 [MMDR Act] to provide rules regarding conservation of minerals, systematic and scientific mining, development of the mineral in the country and for the protection of environment.

KML Boundary Extension

As per IBM, the drone survey should be conducted upto 100 metres outside the lease boundary. If you are confused on how to increase the lease boundary, you can extend your original KML boundary using the KML Boundary Extension free tool from this website.

Enter the website and upload your orginal KML boundary. At the top right corner input the distance in meter upto which you need to extend the boundary and click submit.

Coordinate Reference System

Geographic Coordinate System (GCS)

While a spheroid approximates the earth’s shape, a Datum defines the position of the spheroid relative to the center of the earth. A datum provides a frame of reference for measuring locations on the earth’s surface. It defines the origin and orientation of latitude and longitude lines.

Whenever you change the datum, or the geographic coordinate system, the coordinate values of your data will change.

Data Collection

Linear Mission

Linear missions are used to survey roads, corridors, canals, etc. It is used to analyze line-type features. The default mission shape is a line. Here you can increase the lines according to your mission, place them accordingly, and start the mission. Once the area is marked, and the altitude and lines are set, the drone will automatically fly to the initial point and begin its mission. After reaching the endpoint, it will return to its home position.

Circular Mission

Buildings/Monuments are mapped using the circular mission. It takes a circular flight path, allowing it to capture images from all angles. Once the area has been marked, and the altitude is set, the drone will fly to the initial point and begin its mission. It returns to its home position after reaching the endpoint.

How to fly in mines?

Drones in the mining industry are a pragmatic solution to fix daily problems and play a role in reducing human risk, inspections, and repair costs while also increasing efficiency. However, we must exercise caution when flying drones in mines. When compared to traditional ground surveys, aerial surveys have the upper hand.

To get a good field of view, use the Polygon mission and keep the camera facing the ground.

How to fly in hilly areas?

It is possible to fly a drone in the mountains. However, you may encounter challenges in exceptionally high mountains because the air is less dense at higher elevations. Additionally, you can have shorter flight times due to a more considerable drain on your batteries caused by altitude and cold.

Points to note before flying

• Be aware of your surroundings.
• Fly at high altitudes and increase overlap to identify areas with critical features.
• Keep an eye on the weather, especially the wind.
• Choose a safe elevated area as the home position.

How to fly when there are tall trees and dense vegetation?

Drone technology redefines forestry’s components and contributes to forest ecosystems’ development and improvement. It also contributes to wildlife monitoring, Tree disease Detection, Forest fires, etc.

Points to note before flying

• Fly at high altitudes to ensure you have a clear line of sight.
• Place GCPs in areas where the terrain abruptly changes.
• Set the minimum height above ground to the tallest object’s height + 25m.

How to fly when it is windy?

Most drones can fly in strong winds, but it depends on the specifications of your drone.

Points to note before flying

• Maintain a safe distance from buildings and other obstacles.
• Check the wind speed of the site before flying the drone.
• If the drone becomes unstable, try to land as soon as possible or use the return home feature.
• Fly the drone in the wind’s direction.
• Some drones will have fail-safe features, such as an automatic return-to-home feature when the wind speed exceeds a specific limit. If this occurs, do not attempt to fly the drone again.
• Keep a close eye on the battery.