As part of the calibration work, the surveying of the pyramid needs to be checked, and when this is done two large and highly significant surveying errors are found in the surveys.
The interactive drawing shows the principal ellipse rotated to its natural axial tilt angle and highlighted on the drawing is the ascending passage line, with its object information panel open and showing the constructed angle for this passage of 26° 6' 29.67".
On a previous page (page D9) the construction method for the lower part of the ascending passage was determined, which can be seen again by zooming in on the ascending passage area. The ascending passage is built to an exact length of 33 perfect meters from the hidden start point down to the end of the last plug block that is visible in the passage.
This means that there is no reason whatsoever for the ascending passage to connect with anything at all in the entrance passage, and that the apparent 'start of the ascending passage' that is visible in the roof of the entrance passage MUST be a false construction.
Because of the disconnected nature of the ascending and entrance passages, there is a highly dubious piece of surveying in the pyramid in this area. You can zoom in on the plug blocks to see the area in more detail.
This area of the pyramid was surveyed in the 1800's and has been surveyed only this once, and the results of that survey work have been passed down through the generations and appear in all modern drawings of the pyramid. The technical drawings of the first robotics engineering team in 1993 contain the measurements from this early surveying and unfortunately the original surveying can be shown to be incorrect by a large margin.
The reason for the error is not lack of care and attention on the part of the surveyor, it is that the architects of the building have included the most sophisticated forced perspective optical illusion into the tunnel to ensure that this area will be incorrectly measured. The full analysis of how this error was discovered and the proof of the error can be found in the following academic article which contains a comprehensive explanation of the problems in this area of the pyramid.
The result of that analysis is that the whole of the internal architecture of the Great Pyramid has been incorrectly placed on ALL existing technical drawings and reports and consequently needs to be adjusted.
If you read that academic article in full, which I would recommend because it contains information essential to understanding the next sections of this work, you will see that these adjustments apply to the internal architecture of the pyramid from the ascending passage upwards, and do not included the entrance passage or the upper northern shaft, which is not attached to the main chamber of the building.