Sidescan Imagery p4.....

These images show the some of the large number of Salmon waiting to ascend the Galway rivers from Corrib during September. They are very selective in where they choose to wait, some areas being completely devoid, others seeming to be a heaving mass of fish.

These sidescan images are in low res (455khz) – the high res imagery (800khz) enables us to easily see individual fish, but lacks the range of lower frequencies.
The standard sonar image shows classic “fish arches” which are produced as the cone of the low frequency regular sonar (83khz) encounters a target at the far edge of the sonar cone, then moves closer as the boat moves forward, and subsequently passes out of the cone at more or less the same range as it entered the cone.

©T Northage 2010

Ballynahinch Lake object
Ballynahinch Lake, strange object
This odd looking object was found in Ballynahinch lake, not far from where a large cannon was found a few years ago. It appears to be a heavy tripod structure with (possibly) a growth of weed hanging onto the top. It certainly needs more investigation.