Indian Bureau of Mines SOP for Drone Survey

Introduction

To leverage the use of technology, it has been proposed to use a combination of digital aerial (Drone and satellite) images to monitor mining activities in the country.The digital aerial images as an emerging technology is increasingly being used in agriculture, environmental, geology, mining, town planning and forestry applications and other applications. Through Satellite imagery, one can view the activities that took place on the ground without human interventions. This can be applicable to the mining sector and mining activities can be monitored through the space. Based on the time series satellite imageries for different periods, change detection study in the mining activities of a mine could be studied mainly pertaining to lateral changes in a broad view. Volumetric calculations can also be done based on stereo pair satellite imageries with certain degree of error.

Drone, typically operate at much lower altitudes as compared to satellites and are also able to provide unique data with regard to spatial resolution and angle of view. Compared to satellite images, drone images can provide lower ground sample distances (GSD) or higher spatial resolutions on the ground.

Drone technology can be extensively applied in the mining sector, i.e. for

i. Carrying out overall survey of mine for monitoring the mining and allied activities in and around the mining area.

ii. Lease boundary demarcation using the Ground Control Points (GCPs) and geo-referencing of the leases, monitoring of illegal mining activities etc.

iii. Volumetric estimation of excavation, reclamation and periodical stock piles monitoring.

iv. Change detection analysis over a period of time using previously surveyed data.

v. Monitoring of land use and environmental impact in and around mining area.

vi. Virtual inspection of mines for regulatory purpose.

vii. Preparation of contour survey and survey map for filing to various regulatory agencies as well internal use of the industry.

1. Drone Agency Registration and Permissions

Registration with IBM is not required for taking up the drone survey in mining areas. Drone Agencies desirous to undertake mine surveys shall adhere to all the rules, regulation, guidelines etc. notified by Directorate General of Civil Aviation (hereafter referred as DGCA) from time to time.

Drone Survey must be conducted as per rules prescribed by the Ministry of Civil Aviation. The survey may also be carried out by lessee themselves by following all the applicable rules and guidelines as mentioned above. Prior to flying of Drone, the lessee shall check the airspace map published by DGCA in the given link https://digitalsky.dgca.gov.in/airspace-map/ or published by DGCA from time-to-time and shall obtain necessary DGCA permission prior to flying in Red and Yellow zones.

2. Drone Specification

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

3. Sensor/Camera Specification and output data resolution:

The camera used in the Drone should be of minimum 20 mega pixel or above resolution RGB camera with capability to capture high quality undistorted pictures. Camera should have the resolution to capture the images less than 5 cm Ground Sample Distance (GSD) or 5 cm per pixel. The Resolution of Digital Elevation Model (DEM) should be 15 cm per pixel or better.

4. Drone flying path and flying height:

In order to ensure the generation of a height model photogrammetrically (e.g. Digital Surface or Digital Terrain model, DSM & DTM), images should be acquired with proper overlap. The Drone survey should be planned in such a way that the forward (front) overlap should be minimum 80% and lateral (side) overlap should be minimum 70%.The Flying Height of the Drone should be as per DGCA prescribed limits,

however, the resolution of the Drone image should be very high i.e. up to 5cm GSD or 5cm per pixel or better. Camera angle nadir direction should be vertically downwards (90-degree angle) while carrying out survey.

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 & 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.

6. Ground Control Points (GCPs) for Drone Survey:

Before undertaking Drone Survey, each mine must establish at least five GCPs per sq. km. of lease area or part thereof with calibrated/certified DGPS instrument. If the area is less than one sq. km. the minimum GCPs required shall be four nos. The GCPs should be well distributed all over the Survey area. GCP must be easily visible in the images obtained from Drone survey. The Dimensions of GCPs thus established should be minimum 50 cm by 50 cm (marked as X with high contrast colours). At least three permanent GCP shall be placed at undisturbed locations and has to be covered in the subsequent surveys to cross check the error in change detection and other analysis. The error of GCP should be less than 5 cm. The Boundary pillars should not be considered as permanent ground control points.

7. Drone Survey Time

In order to maintain consistency in quality of images, it is recommended to carry out the Drone survey in better light condition when the sun is overhead to minimise the shadows in photographs and it is also suggested to avoid partly cloudy days and high winds.

8. Co-ordinate Reference system

The Co-ordinate reference system to be used for acquiring the Drone survey images will be Geographic Coordinate System (GCS) with WGS84 Datum and Decimal Degrees / Degree Minute Seconds as units. The ortho-mosaic shall be submitted in the Universal Transverse Mercator (UTM) with WGS-84 datum and units as Meters. The GCPs survey data and boundary pillar coordinates data shall be submitted in latitude and longitude (Deg. Min. Sec.) format in WGS 84 datum. The precision of the data submitted in GCS with WGS84 Datum should be in the format as (DD MM SS.SSSSSS)”.

9. Preservation of Raw and Processed Data

As per rule 34A of MCDR 2017, Lessee shall submit processed output images obtained from drone survey to IBM. The lessee shall keep the rawand processed data of each survey in safe custody with them for a minimum period of five years and if at any stage the raw and processed data are required by IBM for verification purpose then the same will be made available to the IBM.

10. Submission of Data to IBM

The processed output data of the drone survey as per Para ten above shall be submitted in soft copy only in storage media (i.e. external hard disk) on or before 1st day of July every year along with the details of the survey carried out as per the format annexed to this SOP at the following addresses.

(1) The Chief Mining Geologist, Indian Bureau of Mines,

GM&MM Cell, 1st Floor, A- Block

Indira Bhavan, Civil Lines,

Nagpur- 440001, Maharashtra