โ Scribed by G.H. Schut
No coin nor oath required. For personal study only.
The Stockholm Congress of the International Society of Photogrammetry adopted a resolution on sign conventions [1] intended to solve difficulties caused by the more or less arbitrary choice of the positive sense of orientation element~ in existing plotting instruments. The resolutfon recommends that instrument manufacturers, authors and teachers adopt I. a right-handed rectangular coordinate system of which 2. the origin is at the proiection centre and in which 3. Z gives the projection d~stanee~ This rather vague and incomplete resolution has been interpreted by Professor Thompson [2] as stating that point 1 is to iuerude not only the positive direction of the coordinate axes, but als0 the rotations about these axes. Thus a rotation is to be taken as positive when it is clockwise about the positive direc~on of its axis. Point 3 is to state that the Z-coordinate wilt be positive downward~
The resolution has met a certain amount of criticism from Arthur [3] primarily because of the insistence on right-handedness and the choice of Z positive downward. This criticism, however, does not exhaust the case against the resolution; particularly against po~ts 2 and 3. Tl~e following paragraphs suggest further points for consideration in the hope that eventually a generally acceptable coordinate system may be adopted.
๐ SIMILAR VOLUMES
The conventions for positive and negative current and potentials at electrodes carrying a.c. are discussed. Resume-On a discute les conventions pour les courants et les potentiels positifs et negatifs aux electrodes ou passent les courants alternatifs. Zusammenfa~sung-Die Konventionen fUr positive