/// <summary>
/// UTM/UPS string for the alternate zone, with hemisphere override.
/// </summary>
/// <param name="northp">hemisphere override</param>
/// <param name="prec">precision (relative to about 1m)</param>
/// <param name="abbrev">if <see langword="true"/> (the default) use abbreviated (<c>n</c>/<c>s</c>) notation for hemisphere;
/// otherwise spell out the hemisphere (<c>north</c>/<c>south</c>).</param>
/// <returns>UTM/UPS string representation: zone designator, easting, and northing.</returns>
public string ToAltUTMUPSString(bool northp, int prec = 0, bool abbrev = true)
{
var(e, n, _) = UTMUPS.Transfer(_alt_zone, _northp, _alt_easting, _alt_northing, _alt_zone, northp);
return(UTMUPSString(_alt_zone, northp, e, n, prec, abbrev));
}
