All electronic devices must be switched off for take-off and landing (with a very few exceptions).
Anyone who has ever flown on a commercial aircraft will know this as it is mentioned during the safety briefing and on the safety briefing card.
Any equipment installed in the aircraft will have been designed and certified to the most rigorous standards. A GPS installed in a camcorder will not. It may or may not comply with any standards. It is an unknown quantity and must be treated as such. Also, any receiver will emit electromagnetic radiation, as will many devices not containing either receiver or transmitter.
A search would have revealed all of this.