WD Clinger post 751 linked:
http://www.internationalskeptics.com/forums/showpost.php?p=6683849&postcount=751:
"You're right about his insistence upon performing all measurements and calculations within a coordinate frame that's 13.8 degrees (he had been saying 12 degrees) off plumb. He also disregards video from other viewpoints, using them only as sanity checks. Some of his other mistakes are identified in the recent posts by tfk, BasqueArch, and Reactor drone. In short, his entire approach is fundamentally unsound.
There's nothing fundamentally unsound about using a ridiculous coordinate frame for all calculations, and he does calculate the tilt by subtracting the tilt of his coordinate frame from the total rotation he believes he has calculated. The problem with using a ridiculous coordinate frame is that it makes calculations more complex, and he's been having a lot of trouble with that added complexity. His ridiculous coordinate frame has contributed to his mistakes and has discouraged him from correlating his data with data obtained from other sources."
Every sentence is incorrect.
The Sauret projection is just one of 3 projections that have been traced and plotted. There at least 5 projections (viewpoints) of usable WTC1 collapse initiation footage, but only 3 can give accurate trace and drop data: Sauret, NBC NW and NBC NE. Drop curves have been available for all 3 viewpoints since the posting of the OP.
The Sauret projection is a great way to introduce the concept of viewer coordinate systems and viewer projections of vectors, because the video is of very high resolution and taken from almost directly north, lending itself to a 2-D formulation. There are many advantages to the Sauret projection of the event, and a person who studies it carefully will never believe in the claim of rigid tilt again.
If you look at the proof of deformation using drop curves link, you will see at least 2 viewpoints are used.
If this 2-D viewer and building coordinate system formulation works, I will extend the vector approach to 3-D and apply it to at least 2 other viewpoints. Using projections of the event from at least 3 viewpoints, some basic 3-D displacement vectors for point a and point r can be reconstructed.
You have repeatedly claimed that I am working from some funky coordinate system of my own invention. This is untrue. We are interested in how true 3-D movement projects towards different viewers. Your claim that I consider the antenna to be inline with the north wall is also untrue.
On the other hand you have offered some good advice. Thanks.