Monitoring fish migration in Rivers. Helge Balk Department of Physics. University of Oslo. River Tana. River Tana. Tornio (Se/Fi). River Reisa (north Norw.). River Fischa in Austria. 4-Ch TVG. Echosounder in the river. Amplitude Detector. 1 size correction. Phase detector.
Department of Physics. University of Oslo.
TVGEchosounder in the river
1 size correction
Estimate the DPF
Reduce the variation in the DPF
Fish detection software
Measure noise level as a function of time and range over years
Apply noise level as an overall fish size threshold
Use noise level to correct the number of fish within each size group
Apply time expansion to find the total fish abundance estimate
Interpretation: Area expansion
Where did the fish pass?
Index or total run?
Alternative methods to establish the size?
Beam intensity mapping?
Apply reference targets?
Multiple narrow beams?
Aspect detection and correction?