This is an example of finding Longitude and Latitude of an item using the basic Maps App on an iPhone. The same thing could be done using the Google Maps app on an iPhone or Android phone. The advantage of using a mobile device like an iPhone is that you can be in the field and know where you are relative to the view in the satellite map.
This is a photo of a tree in the area between Court 16 and Court 11.
This is a screen shot from Apple Maps on an iPhone. The tree shows up on the satellite view, so we know its location. If the tree did not show up on the satellite view because it was planted after the satellite date, it can be located by reference to other items that are visible, like the buildings (blue lines).
By touching and holding on the map, we can add a marker. It doesn't have to be exactly where the tree is. To place the marker over the tree location, tap on the Move button.
Aftert pessing the Move button, the Marked Location stays centered on the screen and you can drag the map around it until it is exactly on the tree. Once the marker is where you want it, press Done at the top right of the screen.
Scroll down on the screen to read the Coordinates. This is the final, precise location of the tree.