Editorial Notes #

Transformation of Map Graticules #

Note 1: Snyder text refers to $\phi_1$ although the figure (Figure 5) shows $\phi_0$↩︎

Auxiliary latitudes #

Note 1: Snyder shows value $39.762435^\circ$.↩︎

Oblique Mercator #

Note 1: Snyder repeats sphere radius and central scale factor, although they are not needed for these formulas. Also, seems latitude of central point is arbitrarily chosen ($\phi_c=20^\circ$) with longitude and central line azimuth back-calculated from formulas (9-7) and (9-8).↩︎

Note 2: Snyder presents first forward equations for Alternate B, followed by the inverse equations for Alternate A. Here the presentation order is swapped to reuse the projection parameters.↩︎

Cylindrical Equal-Area #

Note 1: Snyder comments on the formula for $x$: “adding $\pi$ since denominator is negative”. In this case however, the ATAN2 function should be used and, since the numerator is also negative, $\pi$ should be subtracted from the result.↩︎

Note 2: This numerical example contains an error: formula for $q$ uses the value for $\phi_s$ instead of the value for $\phi$.↩︎

Note 3: This numerical example contains an error: formula for $\lambda_p$ is missing the factor $\cos(\lambda_1)$ from the first term.↩︎

Note 4: WGS84 coefficients are calculated as shown here↩︎↩︎

Stereographic #

Note 1: Incorrect equations numbers ↩︎

Modified Stereographic #

Note 1: One of the equations in (26-6) is incorrectly shown as $g_f = A_f + iB_f$. Here it is shown correctly as $g_m = A_m + iB_m$. ↩︎