I have read in the Internet that in the most cases people prefer using INS (accelerometer + gyroscope) + GPS sensors. I have read they can compensate each other errors, but is it possible to obtain the same result using accelerometer + magnetometer + GPS sensors? Or accelerometer + gyroscope + magnetometer? I have also read that gyroscope requires lot of battery, so my question is: what is the system which can give me the same result of IMU + GPS, without using gyroscope? If it is not possible, can I just use 9 axis system without GPS?
I know that it depends on the application I want to use, but just let's consider I would like to realize a medium/high level application, so I need it to be precise, but I can afford to have some (very) small errors. If there is a paper which compares the performance of the system I mentioned, please link it :)
Thank you in advance for your answers.