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Real-Time Automatic (AI) Processing NocMig Setup (1 Viewer)
- Thread starter TGiles98
- Start date
Jon.Bryant
Well-known member
Hmmm, you will get me started again on whether you should use a parabola for nocmig recordings. I never seem to get to the bottom of things, and my own experiments have failed so far through lack of migrants.
My argument is that parabolas are very directional, so you will only get increased gain from a small zone of sky. Something makes me think that you would capture more sounds if you can point the parabola in the likely direction of travel, but then approaching birds will be more distant, so not sure this helps.
When I have tried nocmigging, I have used an omni mic with good sensitivity and it has worked OK.
My argument is that parabolas are very directional, so you will only get increased gain from a small zone of sky. Something makes me think that you would capture more sounds if you can point the parabola in the likely direction of travel, but then approaching birds will be more distant, so not sure this helps.
When I have tried nocmigging, I have used an omni mic with good sensitivity and it has worked OK.
Vollmeise
Well-known member
Well, I love to use my Parabolic Dish with 4 AOM5024L omni capsules placed in focal point of the parabola.
The point is, as the capsules show an omnidirectional characteristic, You'll get each passing migrant not in focus of the dish as if there was no parabolic dish at all.
Plus bird calls that are captured by the focus of the parabolic dish are recorded more amplified.
This means, You won't loose any calling migrants that can be heared with your ears and and even weaker calls can be captured (e.g. from greater heights) if they are in focus.
The point is, as the capsules show an omnidirectional characteristic, You'll get each passing migrant not in focus of the dish as if there was no parabolic dish at all.
Plus bird calls that are captured by the focus of the parabolic dish are recorded more amplified.
This means, You won't loose any calling migrants that can be heared with your ears and and even weaker calls can be captured (e.g. from greater heights) if they are in focus.
Jon.Bryant
Well-known member
Good point. You should get everything, except for birds behind the dish.
Do you point the parabola upwards or say at 45 degrees from the horizon, aligned with the likely direction of travel? Something says if the bird is passing obliquely across the focus, the chance it calls in the narrow window seems low. But if it travels through the focus at an angle, it will take longer to pass through and chances of a call will be better. What is your experience?
Of course you can use a parabola with an inward facing cardiodal mic, which is highly directional, but would definitely have reduced capture of sounds outside the focus.
Saxatilis
Well-known member
Hi all, I have been doing nocmig since 2015 and I have used both the Primo EM172 omni capsules and the AOM 5024, both in parabolic dishes and, at the beginning, even mounted on different supports. In both cases I have had some positive results, but essentially scarce due to the lack of appreciable numbers of nocturnal migrants. As you have been told, with the parabolic dish you should capture weak signals, even if out of focus. I live on the outskirts of a mid-size city, in a seven-story building on the ground floor, where I have a garden; over the years I have tried to point the dish where I had detected the presence of diurnal migrants along a small migration line. Despite the horrible background noise of the city and the general lack of feedback so far, I continue to do nocmig with the parabolic mics.
