Sara2001 Finding the satellites and login to the mobile network costs the most energy.
Yes, it does but you can design it in a way that it will run more than one day without charging.
Sara2001 The GPS tracker also works at least much much better when there is nothing between the device and the tracker. So a technically a GPS tracker in a collar that look like jewelry would make more sense.
Yes, the best solution is if the GPS antenna has a free view to the sky to find many satellites. Around the neck would be the best place.
You can design the antenna in a way which is integrated in the metal part of the CB or collar which will be water proof.
Sara2001 From my experience waterproof technic is many times more expensive
Not really. You have to consider it early at the design phase. It will cost some amount more but the most money you spend for the time you need to design it. Let say you need one year. A skilled engineer cost the company over all €150.000 to €200.000. If you sell 1000 pieces per year over 10 years a device would cost €1500 + material + production + profit.