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diff --git a/docs/images/calcofi.png b/docs/images/calcofi.png Binary files differnew file mode 100644 index 00000000..1e07aa72 --- /dev/null +++ b/docs/images/calcofi.png diff --git a/docs/source/projections/calcofi.rst b/docs/source/projections/calcofi.rst index 8611d46a..6588bcca 100644 --- a/docs/source/projections/calcofi.rst +++ b/docs/source/projections/calcofi.rst @@ -4,7 +4,99 @@ Cal Coop Ocean Fish Invest Lines/Stations ******************************************************************************** -.. image:: ./images/calcofi.png +The CalCOFI pseudo-projection is the line and station coordinate system of the +California Cooperative Oceanic Fisheries Investigations program, known as CalCOFI, +for sampling offshore of the west coast of the U.S. and Mexico. + ++---------------------+----------------------------------------------------------+ +| **Classification** | Conformal cylindrical | ++---------------------+----------------------------------------------------------+ +| **Available forms** | Forward and inverse, spherical and elliptical projection | ++---------------------+----------------------------------------------------------+ +| **Defined area** | Only valid for the west coast of USA and Mexico | ++---------------------+----------------------------------------------------------+ +| **Implemented by** | Frank Warmerdam | ++---------------------+----------------------------------------------------------+ +| **Options** | ++---------------------+----------------------------------------------------------+ +| `No special options for this projection` | ++---------------------+----------------------------------------------------------+ + + +.. image:: ../../images/calcofi.png :scale: 50% - :alt: Cal Coop Ocean Fish Invest Lines/Stations + :align: center + :alt: Cal Coop Ocean Fish Invest Lines/Stations + +The coordinate system is based on the Mercator projection with units rotated -30 +degrees from the meridian so that they are oriented with the coastline of the Southern +California Bight and Baja California. Lines increase from Northwest to Southeast. +A unit of line is 12 nautical miles. Stations increase from inshore to offshore. +A unit of station is equal to 4 nautical miles. The rotation point is located at +line 80, station 60, or 34.15 degrees N, -121.15 degrees W, and is depicted by +the red dot in the figure. By convention, the ellipsoid of Clarke 1866 is used to +calculate CalCOFI coordinates. + +The CalCOFI program is a joint research effort by the U.S. National Oceanic and +Atmospheric Administration, University of California Scripps Oceanographic Institute, +and California Department of Fish and Game. Surveys have been conducted for the +CalCOFI program since 1951, creating one of the oldest and most scientifically +valuable joint oceanographic and fisheries data sets in the world. The CalCOFI +line and station coordinate system is now used by several other programs including +the Investigaciones Mexicanas de la Corriente de California (IMECOCAL) program +offshore of Baja California. The figure depicts some commonly sampled locations +from line 40 to line 156.7 and offshore to station 120. Blue numbers indicate line +(bottom) or station (left) numbers along the grid. Note that lines spaced at +approximate 3-1/3 intervals are commonly sampled, e.g., lines 43.3 and 46.7. + +Usage +############################################################################### + +A typical forward CalCOFI projection would be from lon/lat coordinates on the +Clark 1866 ellipsoid. For example:: + + proj +proj=calcofi +ellps=clrk66 -E <<EOF + -121.15 34.15 + EOF + +Output of the above command:: + + -121.15 34.15 80.00 60.00 + +The reverse projection from line/station coordinates to lon/lat would be entered +as:: + + proj +proj=calcofi +ellps=clrk66 -I -E -f "%.2f" <<EOF + 80.0 60.0 + EOF + +Output of the above command:: + + 80.0 60.0 -121.15 34.15 + +Mathematical definition +################################################################################ + +The algorithm used to make conversions is described in [EberHewitt1979]_ with +a few corrections reported in [WeberMoore2013]_. + + +Further reading +################################################################################ + +#. `General information about the CalCOFI program <http://www.calcofi.org>`_ +#. `The Investigaciones Mexicanas de la Corriente de California <http://imecocal.cicese.mx>`_ + + + + + + + + + + + + + diff --git a/docs/source/references.rst b/docs/source/references.rst index 88b5fb26..80b86c55 100644 --- a/docs/source/references.rst +++ b/docs/source/references.rst @@ -1,4 +1,4 @@ -.. _references:: +.. _references: ================================================================================ References @@ -11,4 +11,8 @@ References .. [Steers1970] Steers, J.A., 1970, An introduction to the study of map projections (15th ed.): London, Univ. London Press, p. 229 -.. [Snyder1987] Snyder. John P. 1987. `Map Projections - A Working Manual <https://github.com/OSGeo/proj.4/blob/master/docs/old/USGS-Snyder-Map-Projections-A-Working-Manual-1987.pdf>`__. US. Geological Survey professional paper; 1395. +.. [Snyder1987] Snyder. John P. 1987. `Map Projections - A Working Manual <https://github.com/OSGeo/proj.4/blob/master/docs/old/USGS-Snyder-Map-Projections-A-Working-Manual-1987.pdf>`_. US. Geological Survey professional paper; 1395. + +.. [EberHewitt1979] Eber, L.E., and R.P. Hewitt. 1979. `Conversion algorithms for the CALCOFI station grid <http://www.calcofi.org/publications/calcofireports/v20/Vol_20_Eber___Hewitt.pdf>`__. California Cooperative Oceanic Fisheries Investigations Reports 20:135-137. + +.. [WeberMoore2013] Weber, E.D., and T.J. Moore. 2013. `Corrected Conversion Algorithms For The Calcofi Station Grid And Their Implementation In Several Computer Languages <http://calcofi.org/publications/calcofireports/v54/Vol_54_Weber.pdf>`__. California Cooperative Oceanic Fisheries Investigations Reports 54. |
