From the study of the surveying errors contained in Smyth's original survey of the pyramid the fact that the upper northern shaft is a deceptive piece of architecture was established. If you zoom into the antechamber and main chamber area of the building you can see the two sections of the shaft shown on the interactive drawing. The section of shaft that starts inside the main chamber of the building is of an unknown length.
The second section of this shaft is the false section which runs from the tunnel at the back of the main chamber, also for an unknown length. The layout of these sections of the upper northern shaft are shown in the following illustration which shows the currently known format of these shaft taken from a literal interpretation of the surveying data.
These shaft sections need to be explored and a simple provisional exploration can be carried out with very little effort. A camera needs to be inserted in the horizontal section of the lower northern shaft inside the main chamber and pushed along its 2.63 m length and a photograph or video taken up the angled section of the shaft. This investigation is so trivial to perform that it could be accomplished using a 'selfie stick' and mobile phone by anyone.
The section of the shaft in the tunnel that leads back towards the main chamber needs to have a camera inserted down it to have a provisional look at its construction. It is likely that this shaft contains a sharp right angled bend in it and that, if it is to be explored robotically, that the robot will have to be a miniature device.