Mike - You are right these things are also used for inspecting utility tunnels, that was where I started my research and hit the 500M barrier. Totally agree that to get the distance I need it will have to be a combination of dragging and laying the cable. I was wondering if I could get a coating on the cable with a low co-efficient of friction, PVC is very sticky.
Rod - I saw a programme on cave rescue teams and they were managing to use radios to communicate to the surface. The problem for me though is data rates, voice over low frequency is one thing but video (at inspection quality) is a whole other ball game. I did wonder about using a low rate so that the operator could control the machine but then if a fault is spotted the machine stops and concentrates on the problem for a while and so lets a detailed picture build up. Problem being that I don't know if you would even see the faults on a low res picture.
John - Thanks for the info, I will check Kalatel out.
Rod - I saw a programme on cave rescue teams and they were managing to use radios to communicate to the surface. The problem for me though is data rates, voice over low frequency is one thing but video (at inspection quality) is a whole other ball game. I did wonder about using a low rate so that the operator could control the machine but then if a fault is spotted the machine stops and concentrates on the problem for a while and so lets a detailed picture build up. Problem being that I don't know if you would even see the faults on a low res picture.
John - Thanks for the info, I will check Kalatel out.
