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-rw-r--r--src/PJ_lcca.c49
1 files changed, 47 insertions, 2 deletions
diff --git a/src/PJ_lcca.c b/src/PJ_lcca.c
index 7d1355b9..cf1aa83f 100644
--- a/src/PJ_lcca.c
+++ b/src/PJ_lcca.c
@@ -1,5 +1,50 @@
-/* PROJ.4 Cartographic Projection System
-*/
+/*****************************************************************************
+
+ Lambert Conformal Conic Alternative
+ -----------------------------------
+
+ This is Gerald Evenden's 2003 implementation of an alternative
+ "almost" LCC, which has been in use historically, but which
+ should NOT be used for new projects - i.e: use this implementation
+ if you need interoperability with old data represented in this
+ projection, but not in any other case.
+
+ The code was originally discussed on the PROJ.4 mailing list in
+ a thread archived over at
+
+ http://lists.maptools.org/pipermail/proj/2003-March/000644.html
+
+ It was discussed again in the thread starting at
+
+ http://lists.maptools.org/pipermail/proj/2017-October/007828.html
+ and continuing at
+ http://lists.maptools.org/pipermail/proj/2017-November/007831.html
+
+ which prompted Clifford J. Mugnier to add these clarifying notes:
+
+ The French Army Truncated Cubic Lambert (partially conformal) Conic
+ projection is the Legal system for the projection in France between
+ the late 1800s and 1948 when the French Legislature changed the law
+ to recognize the fully conformal version.
+
+ It was (might still be in one or two North African prior French
+ Colonies) used in North Africa in Algeria, Tunisia, & Morocco, as
+ well as in Syria during the Levant.
+
+ Last time I have seen it used was about 30+ years ago in
+ Algeria when it was used to define Lease Block boundaries for
+ Petroleum Exploration & Production.
+
+ (signed)
+
+ Clifford J. Mugnier, c.p., c.m.s.
+ Chief of Geodesy
+ LSU Center for GeoInformatics
+ Dept. of Civil Engineering
+ LOUISIANA STATE UNIVERSITY
+
+*****************************************************************************/
+
#define PJ_LIB__
#include <errno.h>
#include <proj.h>