Welcome to NRSC

At present NRSC operates two Beechcraft Super King Air 8-200 aircraft with call signs VT -EQK AND VT -EBB.

These are pressurized twin turbo prop executive aircraft, which have been specially modified to include dual camera port for standard wide angle and superwide angle cameras. In addition to the camera ports, the aircraft can also house Multispectral scanner or Aeromagnetic system or Synthetic Aperture Radar (SAR). Extensive structural modifications and instrumentation have been carried out in the aircraft and it has been certified by Federal Aviation Agency (FAA), USA and Director General of Civil Aviation (DGCA), India. The aircraft is capable of carrying out aerial surveys from 400 feet to 35,000 feet and hence photo scales from 1 :400 up to 1 :120,000 can be achieved.

The aircraft has fast rate of climb and high cruising speed thus enabling the aircraft to reach the survey area at the shortest possible time. The large endurance of the aircraft is effectively utilised for airborne remote sensing surveys. The aircraft is also used for carrying out low altitude Aeromagnetic and Radiometric surveys thus making it truly versatile platform for remote sensing data acquisition with various sensors at the various altitudes.

NRSC aircraft have Trimble Globa l Positioning System Receiver for Navigation and Trimble Geodetic Receiver for Airborne Kinematic GPS with ground reference for determination of camera exposure point. The aircraft is equipped with Computer Controlled Navigation System (CCNS) linking Kinematic GPS to camera for pinpoint aerial photography of predetermined ranges thus reducing considerably the aerial photography acquisition time and cost

The lens used in the above cameras has resolution of 70 lines / mm. The format size is 23 cm X 23 cm. The above cameras are metric cameras which are used for vertical photography with appropriate overlaps for obtaining stereo aerial photographs for photogrammetric applications. Films which are normally used for aerial photography in the above cameras are:

All the above cameras are modified to give triggering pulses to GPS receiver for operation in Kinematic mode.

Aerial photography includes facilities for flight planning using World Wide Mission Planning (WWMP) software, which provides inputs tothe aircraft Computer Controlled Navigation System (CCNS) to optimise flight duration, thus achieving aerial photography of international standards.

From the combination of the available cameras, films and quality of photo processing, aerial photography resolution of 40 lines / mm or 25 microns of the scale of photography can be achieved.

Aeromagnetic surveys are recognised world wide as an established tool for most of the mineral, petroleum and ground water explorations. Magnetometer is an instrument for measuring the intensity of the earth's magnetic field. Most rocks contain some magnetite, the most common magnetic mineral and therefore produce some disturbances in the magnetic field. Through interpretation of magnetometer readings obtained over large areas, assumptions are made about what exists beneath the surface, whether it is a pipeline, a particular mineral, a geological structure, sedimentation zone suitable for oil exploration etc. The earth's magnetic field intensity will be measured in 'nT' (nano Tesla) units and the field values lies within the range of 20,000 nT to 1,00,000 nT.

The system is installed in the Super King Air 8-200 aircraft with the sensor strapped down to the aircraft tail boom. The airborne system comprises of high sensitivity Cesium magnetometer from Mls Scintrex, Canada, with associated electronics, 3 axis compensation system and a data acquisition system. The magnetometer has a sensitivity of 0.001 nT (nano Tesla) and a recording accuracy of 00.1 nT.

The data acquisition system collects data from Global Positioning System (GPS), radio altimeter, magnetometer, fiducial number, data and time of flight etc. The data is recorded on hard disk of note book PC.The AADC System has been integrated with Airborne Magnetometer for Real Time Compensation of Magnetic Data. A ground magnetometer simultaneously records the magnetic intensity and time for diurnal corrections.

The SLAR and SAR are active microwave sensors aimed at obtaining images of earth's features by observing the reflected electromagnetic radiation from the earth's surface. It is an all weather sensor which can be used to obtain images of earth surface either at day or night or even under cloud cover.

All weather capability except heavy rains.
Day I night operations.
Haze, clouds penetration.
To study about soil moisture under vegetation.
Mineral exploration.
Geological featuring detection & bed rock investigation.
Landuse I land cover studies.
Detection of buried pipes (metallic and non metallic) and utility cables.
Location of voids and determination of other subsurface conditions under highways and bridges.
Detection of hidden objects and voids in walls and tunnels.
Measurement of ice thickness and location of prima frost.

Horizontal and vertical controls will be executed using the following systems to meet the standard map accuracies.

35 Differential Global Positioning Systems (GPS) capable of being used in differential mode and GPS data processing systems (Leica SR 500 GR, Leica SR 9500 GR, Trimble 4000 SSE geodetic receivers) with post processing software for accurate ground control surveys. These systems provide data to an accuracy of 5mm + 1ppm (parts per million).
1 Electronic Theodolites with Electronic Distance Measurement (EDM) from M/s Leica with 4 km range for ground surveys.
2 Digital Levels from M/s Leica for providing accurate height control.

AS&DM has the state-of-art technology for carrying out following photogrammetric applications, using aerial photographs and stereo satellite data.

Creating GIS compatible 3-dimensional digital terrain data base, using appropriate symbology for different data types such as polygons, lines, points etc..
Aero triangulation for generating sufficient number of control points in each model (densifying the minimum ground control established in the field)for subsequent photogrammetric jobs by collecting model coordinates of control points for further use in transformation into ground coordinate system.
Block adjustment which provides best solution i.e. triangulation and transforms the model coordinates of the control points into ground coordinate system.
Creating Digital elevation models (DEM) / Digital terrain models (DTM).
Generating contours from DEM / DTM.
Generating orthophotographs.
End products include topographical base maps, contour maps, orthoimages, profiles, cross sections etc. These are supplied in soft copies in dxf and dwg formats on computer tapes, disks, etc. , as well as hard copies on transparent films and special coated inkjet paper.

The following systems are used to effectively carry out the above mentioned applications:

Soft Copy Digital Photogrammetry System on Silicon Graphics work station with dual monitor with softplotter software for orientating the aerial images, for aerotriangulation, block adjustment, creating automatic digital elevation models and generating digital orthoimages. Kork digital mapping software (KDMS) helps in stereo digitisation by viewing through crystal eye glasses. The system is attached to HP inkjet plotter to generate outputs.

DSR -15 Analytical Photogrammetry System from Mls Leica, Switzerland supported by MicroVAX 3100 and VAX 4000 workstation with suitable software for 3D-digital topographic data capture in Infocam environment, aerotraingulation, digital elevation modelling (DEM) I digital terrain modelling (DTM) data capture, block adjustment using PATMR software, data processing. The system is attached to TA-10 flat bed plotter with scribing and peeling options for precision plotting.

SD-2000 Analytical Photogrammetry system from M/S Leica, Switzerland with software for aerotriangulation, DEM / DTM data capture, topographic, mapping in Microstation environment. The system is interfaced to TA-10 flat bed plotter .

SSK Pro (Digital Photogrammetric System) from M/s Intergraph, USA for aero Triangulation.

Photogrammetric high precision SCAI scanner from M/S Leica, Switzerland, to convert analogue aerial photos to digital images for subsequent use in digital photogrammetry systems. Photographs can be scanned at different resolutions varying from 7 microns to 224 microns depending on input data resolution and required output data resolution. Provision to scan B&W, Colour images. Software enables to adjust density and histogram values to make the brightness of the image even throughout the image.

PC digitiser and work station ARC / INFO systems for digitisation, building up of geographical information systems, urban information systems, land information systems etc.

Autocad Map 2000 for 2D digitization, data conversions and generation of soft copy and hard copy maps.

Storage, Archival and Networking System comprises of CISCO routers, Network Attached Stroage (NAS) System, backup devices, as well as IBM TIVOLI Management Software