GPS Location

GPS is achieved from the trilateration principle. The position is determined by the intersection of spheres from the known position of the transmitted signals by the satellites. The central point is evaluated from the signals that adjoin to a common point from the transmitted signals. In other words, data from a single satellite gives an idea of the location coordinates within a zone on the Earth's surface. The second satellite can assist in finding the location coordinates in a common zone between the two. However, the third satellite will give an accurate set of coordinates reducing the common zone of the possible location coordinates. Therefore, GNSS modules require 3 satellites to attain an accurate position, and the fourth satellite or even more satellites will elevate the precision of the location coordinates. It also offers variables such as altitude, and the elevation of the signal.

You can place the GNSS modules at any location with a clear view of the sky. However, this is not completely true in all cases until some criteria are met. It is preferable to avoid populated areas, although, it is not possible to attain such an environment unless the base station is placed on top of the building. It is recommended to avoid tall buildings in dense areas and any visible obstacles. The main goal is to attain a clear 360-degree view to ensure the station can attract most of the signals from all the constellations. Unquestionably, an open field would be an ideal scenario. In addition, using a bigger ground plane for the antenna assists the incoming of the satellite signals. This improves the signal return on the ground plane giving rise to better accuracy. A ground plane is a piece of conductor positioned under the antenna. RTK simply improves the location coordinates obtained from a GPS module.

Autonomy

You can use a power bank to power the GNSS module and make it autonomous.