Airborne Geophysics
KORAL company provide with cooperation with partnership organization Airborne geophysical prospecting.
KORAL offers:
1. Establishing professional logistic and expert team
2. Development of contract
3. Preparation of maps and others data prior to flying
4. Permissions
5. Airborne survey, data acquisition
6. Quality control of survey data
7. Preliminary products
8. Final maps and reports, delivering to client
Airborne geophysical survey is modern effective geophysical method, which provide fast
geophysical imagine from large area.
Position of measurement
-Vertical position along flight lines is established using three instruments / methods - Pressure altimeter, radar altimeter or laser altimeter and GPS.
-Horizontal survey positions is established from real time or post processing corrected GPS system.
Magnetic data
Magnetometer sensor is in case of helicopter under machine on about 20 m long safety rope. In case of plane is fixed on the back part of plane in special tube. Normal helicopter speed is close to 130 km/h, plane 200 km/h. Sampling rate is 0.1 s. Computer acquisition system store all magnetic data and also support data / real time corrected GPS coordinates, pressure, temperature, humidity, fluxgate informations, radar altimeter/. For Diurnal correction is using magnetic basestation with sample rate 0.1 or 1s located in quiet magnetic field near survey area. Member of Exploration crew is also Quality control technician/ geophysicist/, who take care about quality and correctness surveyed data after each flight.
Processing of magnetic data:
a. Identify and remove incidental noise
b. Identify systematic errors
c. Identify systematic noise
d. Apply diurnal correction
e. Apply Lag correction
f. Apply Heading correction
g. Apply IGRF
h. Performing tie levelling
i. Performing full levelling
j. Performing microleveling
k. Performing careful levelling
l. Processing of derivate maps
m. Layout of maps
n. Printings of maps
Spectrometry data
For measurement of spectrometry data we use Gammaray Spectrometer System / 256 channel/ with downward and upward sensors. It is self-stabilizing spectrometer. Stability is check by daily standard calibration procedures. Sample rate is 1 s. Support measurements are real time corrected GPS, radar altimeter, barometric pressure, temperature, humidity.
Processing of radiometric data:
a. Dead time correction
b. Aircraft background removal
c. Cosmic background correction
d. Radon background removal
e. Spectral Stripping correction
f. Effective high calculation
g. Attenuation correction
h. Conversion of count rates to ppm values
i. Layout maps
j. Printing of maps
TEM data
Helicopter transient electromagnetic system. Time-domain, helicopter electromagnetic system is designed mainly for hydro geophysical and environmental investigation. System is independent of the helicopter, the entire system is carried as an external sling load. Result of processing is resistivity distribution maps. Quality of measurement is comparable or better to ground-based system.
