@title{PROJ}{Projection Reference}
@keyword{kernel projections parameter georeference segment set}
@index{Projections}

 Why are projections needed for image processing?  Projections are 
 required to tie-down an image to the earth's surface.  Once the
 required projection information has been defined and the image
 has been corrected to overlay the projection bounds, image
 equirectangular pixel and line coordinates can be transformed
 to produce equirectangular projection easting and northing
 coordinates which can be transformed with the projection formulas
 to produce equivalent non-equirectangular longitude and latitude
 coordinates.  Or the inverse can be done: longitude and latitude
 coordinates can be transformed to projection easting and northings
 and image database pixel and line coordinates.

 Projections are useful to compensate for distortions in large-scale
 imagery that cover a large earth surface, where distortions are
 produced from earth curvature.  These are the same distortions 
 that occur in projecting a spherical surface (the earth) onto a
 flat surface (the image database).  Although there are still
 distortions in all projections, some are removed or compensated
 for depending on the projection used.

 Once an image is tied to one projection, it can automatically be
 projected to overlay another projection.  This gives you options
 to easily process your data, by matching your goals to the 
 appropriate projection.

 The software used for the projection transforms is the GCTP
 (General Cartographic Transformation Package) produced by the
 U.S. Geological Survey (See the REFERENCES section.).  It can
 be used to convert:

 - projection coordinates to geographic coordinates
 - geographic coordinates to projection coordinates
 - projection coordinates to coordinates in a second projection

 The conversions must use the same earth model (ellipsoid or sphere).
 The package is NOT meant to be used to convert between systems with 
 different earth models.

 Transforming between projections with different earth models 
 requires an actual geometric correction using a first-order affine 
 transform (offsets and possibly scaling and rotation).  Transforms 
 between different earth models is discussed more under the EARTH_MODELS 
 section in program REGPRO.

1	OUTPUT UNITS

 For supported projections, the output map units will take the 
 following output format:

  'proj 9999 r Ennn'

  Where: proj (Characters 1 to 4) is the standard string listed below
         for the projection.  The string is left-justified.  If 
         the standard string is less than 4 characters the string
         is padded with trailing blanks.  (e.g. 'UTM ')

        (Character 5 is blank)

        9999 (Characters 6 to 9) is the zone number, if any.
          - for the UTM projection, depending on the value of 
            the subroutine argument UTMROW, the zone number is
            returned right-justified in the range of '   1' to 
            '  60' (or '  -1' to ' -60').
          - for SPCS projections:  '0101' to '5400'
          - for other projections: '    '

        (Character 10 is blank)

        r (Character 11) is the UTM or UPS grid zone row, if any.
          For all other systems, this is blank.
         
        (Character 12 is blank)

        Ennn (Characters 13 to 16) Ellipsoid used for the projection
          - 'E000' to E019' for supported ellipsoids
          - Default is 'E000' if no earth model is defined in
            MAPUNITS or ELLIPS
          - 'E999' is a special case, where the earth model is
            not supported but was defined in ELLIPS

1	EARTH MODELS

 The following earth models are supported.

  Standard  
   String    Descriptor                   Notes

  E000       Clarke                1866   NAD1927
  E001       Clarke                1880   
  E002       Bessel                1841   
  E003       New International     1967   
  E004       International         1924   Hayford 1909
  E005       WGS                   1972   
  E006       Everest               1830   
  E007       WGS                   1966   
  E008       GRS                   1980   NAD1983
  E009       Airy                  1830   
  E010       Modified Everest             
  E011       Modified Airy                
  E012       WGS                   1984   GPS
  E013       Southeast Asia               
  E014       Australian National   1965   
  E015       Krassovsky            1940   
  E016       Hough                        
  E017       Mercury               1960   
  E018       Modified Mercury      1968   
  E019       Sphere, rad 6370997 m        Normal Sphere

  E999       Unsupported earth model, where the earth model fields
             are defined in an existing georeference segment.

@pagebreak
                                    Semi-Major      Semi-Minor
                                     Axis (A)        Axis (B)
  ELLIPS  Descriptor                 (metres)        (metres)

   0      Clarke            1866  6378206.400000  6356583.800000
   1      Clarke            1880  6378249.145000  6356514.869550
   2      Bessel            1841  6377397.155000  6356078.962840
   3      New International 1967  6378157.500000  6356772.200000
   4      International     1924  6378388.000000  6356911.946130
   5      WGS               1972  6378135.000000  6356750.519915
   6      Everest           1830  6377276.345200  6356075.413300
   7      WGS               1966  6378145.000000  6356759.769356
   8      GRS               1980  6378137.000000  6356752.314140
   9      Airy              1830  6377563.396000  6356256.910000
  10      Modified Everest        6377304.063000  6356103.039000
  11      Modified Airy           6377340.189000  6356034.448000
  12      WGS               1984  6378137.000000  6356752.314245
  13      Southeast Asia          6378155.000000  6356773.320500
  14      Australian Nat    1965  6378160.000000  6356774.719000
  15      Krassovsky        1940  6378245.000000  6356863.018800
  16      Hough                   6378270.000000  6356794.343479
  17      Mercury           1960  6378166.000000  6356784.283666
  18      Modified Mercury  1968  6378150.000000  6356768.337303
  19      Normal Sphere           6370997.000000  6370997.000000

 As it stands, the U.S.G.S. GCTP software, that is used by 
 EASI/PACE programs for conversions between projections, does not 
 convert coordinates between different earth ellipsoids or datums.  
 However there is software available to the public for conversion 
 of NAD1927 coordinates to NAD1983 coordinates.  For Canadian users,
 you can contact the following for the National Transformation 
 package (Version 1.1):

   Geodetic Survey Division,
   615 Booth Street,
   Ottawa, Ontario
   K1A 0E9
   Tel: (613) 992-2706, (613) 995-2613
   Fax: (613) 995-3215

 The National Transformation package is also available through
 the Provincial Survey Agencies.

 For American users, you can contact the following for the NADCON
 package:

   National Geodetic Information Center,
   N/CG174, Rockwall Bldg., Room 24,
   National Geodetic Survey, NOAA,
   Rockville, Maryland 20852
   Tel: (301) 443-8631
   Fax: (301) 881-0154

1	UTM ZONES

 The Universal Transverse Mercator projection divides the earth 
 into 60 UTM zones.  Each zone is 6 degrees wide in longitude.
 The central meridian for the projection is in the middle of the 
 UTM zone.  (The reference latitude for all UTM zones is the equator.)

  UTM       Zone        Central         UTM       Zone        Central
  Zone      Range       Meridian        Zone      Range       Meridian
   1    180W - 174W      177W           31      0E -   6E        3E
   2    174W - 168W      171W           32      6E -  12E        9E
   3    168W - 162W      165W           33     12E -  18E       15E
   4    162W - 156W      159W           34     18E -  24E       21E
   5    156W - 150W      153W           35     24E -  30E       27E
   6    150W - 144W      147W           36     30E -  36E       33E
   7    144W - 138W      141W           37     36E -  42E       39E
   8    138W - 132W      135W           38     42E -  48E       45E
   9    132W - 126W      129W           39     48E -  54E       51E
  10    126W - 120W      123W           40     54E -  60E       57E
  11    120W - 114W      117W           41     60E -  66E       63E
  12    114W - 108W      111W           42     66E -  72E       69E
  13    108W - 102W      105W           43     72E -  78E       75E
  14    102W -  96W       99W           44     78E -  84E       81E
  15     96W -  90W       93W           45     84E -  90E       87E
  16     90W -  84W       87W           46     90E -  96E       93E
  17     84W -  78W       81W           47     96E - 102E       99E
  18     78W -  72W       75W           48    102E - 108E      105E
  19     72W -  66W       69W           49    108E - 114E      111E
  20     66W -  60W       63W           50    114E - 120E      117E
  21     60W -  54W       57W           51    120E - 126E      123E
  22     54W -  48W       51W           52    126E - 132E      129E
  23     48W -  42W       45W           53    132E - 138E      135E
  24     42W -  36W       39W           54    138E - 144E      141E
  25     36W -  30W       33W           55    144E - 150E      147E
  26     30W -  24W       27E           56    150E - 156E      153E
  27     24W -  18W       21W           57    156E - 162E      159E
  28     18W -  12W       15W           58    162E - 168E      165E
  29     12W -   6W        9W           59    168E - 174E      171E
  30      6W -   0E        3W           60    174E - 180W      177E

1	UTM GRID ZONES

 UTM zones divide the earth into columns, west to east.  Each UTM
 zone can be divided into rows, south to north.  If both the UTM
 zone and row are given, the area defined is referred to as a
 UTM grid zone.  For example UTM30N is the area just west of
 Greenwich and just north of the equator.

 A UTM grid zone can be divided further.  However within EASI/PACE,
 the row is only used to determine if the coordinates are north or
 south of the equator.  If the UTM zone is defined and the row is not,
 the coordinates are assumed to be north of the equator.  Coordinates
 north of the equator are assumed to have a false northing of 0.0
 metres while coordinates south of the equator are assumed to have a
 false northing of 10000000.0 metres.

  UTM        Row                        UTM        Row
  Row       Range                       Row       Range
  C      80S -  72S                     N       0N -   8N
  D      72S -  64S                     P       8N -  16N
  E      64S -  56S                     Q      16N -  24N
  F      56S -  48S                     R      24N -  32N
  G      48S -  40S                     S      32N -  40N
  H      40S -  32S                     T      40N -  48N
  J      32S -  24S                     U      48N -  56N
  K      24S -  16S                     V      56N -  64N
  L      16S -   8S                     W      64N -  72N
  M       8S -   0N                     X      72N -  84N

  Note: - There is no row I or row O.
        - All rows are 8 degrees latitude, except row X which has
          12 degrees latitude.
        - Grid zones A, B, Y, and Z exist, but are not valid for
          the UTM projection.  They are used for the polar regions
          (A and B for the South Pole;  Y and Z for the North Pole),
          which are mapped with the Universal Polar Stereographic
          (UPS) projection.

1	UPS GRID ZONES

 In the UPS grid system, which is used instead of UTM in the
 polar areas, each circular polar zone is divided in half by the
 the Prime Meridian (0 degrees Longitude) and 180 degrees Longitude
 (East or West).  There are two grid zones over the North Pole
 (Y and Z) and two over the South Pole (A and B).

 A UPS grid zone can be divided further.  However within EASI/PACE,
 the grid zone is only used to determine if the coordinates are at
 the North or South Pole.

  UPS Grid Zone    Longitude Range    Latitude Range

       A             180W -   0W        90S - 80S
       B               0E - 180E        90S - 80S

       Y             180W -   0W        84N - 90N
       Z               0E - 180E        84N - 90N

  Note: - Grid zones C to X (but not I or O) exist, but are not valid
          for the UPS projection.  They are supported for the UTM
          projection.

1	SPCS ZONES

 The United States of America uses the State Plane Coordinate System 
 as a system of plane rectangular coordinates that may be used
 for measuring ground distance and area.  SPCS uses specified
 projections with set characteristics.  In general, Transverse Mercator
 (TM) is used for States with predominant north-south extent and
 Lambert Conformal Conic (LCC) is used for States with predominant
 east-west extent.  Other projections that may be used are Oblique
 Mercator (OM) in Alaska and Polyconic (PC) in Guam.  The 
 characteristics for each projection are stored in text files 
 "nad1927.txt" and "nad1983.txt" that are provided in the 
 $PCIHOME/etc subdirectory.

 The following is a list of codes for specifying State Plane zones.
 The "Zone Name or Number", "Alpha Code" and "Proj Type" are for your
 information and are NOT to be used to specify SPCS zones.  The
 "zone unit code" is used instead.  For example, to specify the zone for
 Alabama, East you would set MAPUNITS to "spaf 0101" (or "SPAF 101").
 The "units" can be upper or lower-case.  The "code" can have (but doesn't
 require) leading zeros.

 State Plane coordinates are only supported for NAD1927 (which
 uses Clarke 1866 ellipsoid) or NAD1983 (which uses the GRS 1980
 ellipsoid).

 The units for a given zone will be derived from the units string typed in
 where:

 "SPAF" stands for "State Plane (U.S. Survey Feet)", 
        where 1.0 inch of a "U.S. Survey Foot" equals APPROXIMATELY 25.4005 mm.
       (where 1.0 metre equals EXACTLY 39.37 inches)

 "SPIF" stands for "State Plane (International Foot)",
        where 1.0 inch of an "International Foot" equals EXACTLY 25.4 mm.

 "SPCS" stands for "State Plane (Metres)"

 For NAD27, the units are "SPAF" (i.e. "State Plane (U.S. Survey Feet)").
 For NAD83, the units listed are those specified by State Laws as of
 February 1, 1992.  Although these are the suggested units, they may be
 overridden.

 Any of the following work for the above example for NAD27.  (The
 first example assumes NAD 1927, if no earth model is specified.)

  MAPUNITS="spaf 101"      \ ELLIPS=    \
  MAPUNITS="spaf 101 e0"   \ ELLIPS=    \
  MAPUNITS="spaf 101"      \ ELLIPS="0" \

 Any of the following work for the above example for NAD83.

  MAPUNITS="spaf 101 e8"    \ ELLIPS=    \
  MAPUNITS="spaf 101"       \ ELLIPS="8" \

 The following list is copied from Appendix A of the U.S.G.S.
 "GCTP, General Cartographic Transformation Package Software
 Documentation".

                                             NAD27        NAD83
                          Alpha    Proj      zone         zone
  Zone Name or Number     code     type    unit code    unit code

  Alabama                 AL
      East                         TM      SPAF 0101    SPAF 0101
      West                         TM      SPAF 0102    SPAF 0102

  Alaska                  AK
      01                           OM      SPAF 5001    SPCS 5001
      02                           TM      SPAF 5002    SPCS 5002
      03                           TM      SPAF 5003    SPCS 5003
      04                           TM      SPAF 5004    SPCS 5004
      05                           TM      SPAF 5005    SPCS 5005
      06                           TM      SPAF 5006    SPCS 5006
      07                           TM      SPAF 5007    SPCS 5007
      08                           TM      SPAF 5008    SPCS 5008
      09                           TM      SPAF 5009    SPCS 5009
      10                           LCC     SPAF 5010    SPCS 5010

  Arizona                 AZ
      East                         TM      SPAF 0201    SPIF 0201
      Central                      TM      SPAF 0202    SPIF 0202
      West                         TM      SPAF 0203    SPIF 0203

  Arkansas                AR
      North                        LCC     SPAF 0301    SPAF 0301
      South                        LCC     SPAF 0302    SPAF 0302

  California              CA
      01                           LCC     SPAF 0401    SPAF 0401
      02                           LCC     SPAF 0402    SPAF 0402
      03                           LCC     SPAF 0403    SPAF 0403
      04                           LCC     SPAF 0404    SPAF 0404
      05                           LCC     SPAF 0405    SPAF 0405
      06                           LCC     SPAF 0406    SPAF 0406
      07                           LCC     SPAF 0407    ---------

  Colorado                CO
      North                        LCC     SPAF 0501    SPIF 0501
      Central                      LCC     SPAF 0502    SPIF 0502
      South                        LCC     SPAF 0503    SPIF 0503

  Connecticut             CT       LCC     SPAF 0600    SPAF 0600

  Delaware                DE       TM      SPAF 0700    SPAF 0700

  District of Columbia    DC   Use LCC     SPAF 1900    SPAF 1900

  Florida                 FL
      East                         TM      SPAF 0901    SPAF 0901
      West                         TM      SPAF 0902    SPAF 0902
      North                        LCC     SPAF 0903    SPAF 0903

  Georgia                 GA
      East                         TM      SPAF 1001    SPCS 1001
      West                         TM      SPAF 1002    SPCS 1002

  Hawaii                  HI
      01                           TM      SPAF 5101    SPAF 5101
      02                           TM      SPAF 5102    SPAF 5102
      03                           TM      SPAF 5103    SPAF 5103
      04                           TM      SPAF 5104    SPAF 5104
      05                           TM      SPAF 5105    SPAF 5105

  Idaho                   ID
      East                         TM      SPAF 1101    SPAF 1101
      Central                      TM      SPAF 1102    SPAF 1102
      West                         TM      SPAF 1103    SPAF 1103

  Illinois                IL
      East                         TM      SPAF 1201    SPAF 1201
      West                         TM      SPAF 1202    SPAF 1202

  Indiana                 IN
      East                         TM      SPAF 1301    SPAF 1301
      West                         TM      SPAF 1302    SPAF 1302

  Iowa                    IA
      North                        LCC     SPAF 1401    SPCS 1401
      South                        LCC     SPAF 1402    SPCS 1402

  Kansas                  KS
      North                        LCC     SPAF 1501    SPAF 1501
      South                        LCC     SPAF 1502    SPAF 1502

  Kentucky                KY
      North                        LCC     SPAF 1601    SPAF 1601
      South                        LCC     SPAF 1602    SPAF 1602

  Louisiana               LA
      North                        LCC     SPAF 1701    SPCS 1701
      South                        LCC     SPAF 1702    SPCS 1702
      Offshore                     LCC     SPAF 1703    SPCS 1703

  Maine                   ME
      East                         TM      SPAF 1801    SPCS 1801
      West                         TM      SPAF 1802    SPCS 1802

  Maryland                MD       LCC     SPAF 1900    SPAF 1900

  Massachusetts           MA
      Mainland                     LCC     SPAF 2001    SPAF 2001
      Island                       LCC     SPAF 2002    SPAF 2002

  Michigan                MI
      East    (Obsolete)           TM      SPAF 2101    ---------
      Central (Obsolete)           TM      SPAF 2102    ---------
      West    (Obsolete)           TM      SPAF 2103    ---------
      North                        LCC     SPAF 2111    SPIF 2111
      Central                      LCC     SPAF 2112    SPIF 2112
      South                        LCC     SPAF 2113    SPIF 2113

  Minnesota               MN
      North                        LCC     SPAF 2201    SPCS 2201
      Central                      LCC     SPAF 2202    SPCS 2202
      South                        LCC     SPAF 2203    SPCS 2203

  Mississippi             MS
      East                         TM      SPAF 2301    SPAF 2301
      West                         TM      SPAF 2302    SPAF 2302

  Missouri                MO
      East                         TM      SPAF 2401    SPCS 2401
      Central                      TM      SPAF 2402    SPCS 2402
      West                         TM      SPAF 2403    SPCS 2403

  Montana                 MT       LCC     ---------    SPIF 2500
      North                        LCC     SPAF 2501    ---------
      Central                      LCC     SPAF 2502    ---------
      South                        LCC     SPAF 2503    ---------

  Nebraska                NE       LCC     ---------    SPAF 2600
      North                        LCC     SPAF 2601    ---------
      South                        LCC     SPAF 2602    ---------

  Nevada                  NV
      East                         TM      SPAF 2701    SPCS 2701
      Central                      TM      SPAF 2702    SPCS 2702
      West                         TM      SPAF 2703    SPCS 2703

  New Hampshire           NH       TM      SPAF 2800    SPCS 2800

  New Jersey              NJ       TM      SPAF 2900    SPCS 2900

  New Mexico              NM
      East                         TM      SPAF 3001    SPAF 3001
      Central                      TM      SPAF 3002    SPAF 3002
      West                         TM      SPAF 3003    SPAF 3003

  New York                NY
      East                         TM      SPAF 3101    SPAF 3101
      Central                      TM      SPAF 3102    SPAF 3102
      West                         TM      SPAF 3103    SPAF 3103
      Long Island                  LCC     SPAF 3104    SPAF 3104

  North Carolina          NC       LCC     SPAF 3200    SPAF 3200

  North Dakota            ND
      North                        LCC     SPAF 3301    SPIF 3301
      South                        LCC     SPAF 3302    SPIF 3302

  Ohio                    OH
      North                        LCC     SPAF 3401    SPCS 3401
      South                        LCC     SPAF 3402    SPCS 3402

  Oklahoma                OK
      North                        LCC     SPAF 3501    SPAF 3501
      South                        LCC     SPAF 3502    SPAF 3502

  Oregon                  OR
      North                        LCC     SPAF 3601    SPIF 3601
      South                        LCC     SPAF 3602    SPIF 3602

  Pennsylvania            PA
      North                        LCC     SPAF 3701    SPCS 3701
      South                        LCC     SPAF 3702    SPCS 3702

  Rhode Island            RI       TM      SPAF 3800    SPCS 3800

  South Carolina          SC       LCC     ---------    SPIF 3900
      North                        LCC     SPAF 3901    ---------
      South                        LCC     SPAF 3902    ---------

  South Dakota            SD
      North                        LCC     SPAF 4001    SPCS 4001
      South                        LCC     SPAF 4002    SPCS 4002

  Tennessee               TN       LCC     SPAF 4100    SPAF 4100

  Texas                   TX
      North                        LCC     SPAF 4201    SPAF 4201
      North Central                LCC     SPAF 4202    SPAF 4202
      Central                      LCC     SPAF 4203    SPAF 4203
      South Central                LCC     SPAF 4204    SPAF 4204
      South                        LCC     SPAF 4205    SPAF 4205

  Utah                    UT
      North                        LCC     SPAF 4301    SPIF 4301
      Central                      LCC     SPAF 4302    SPIF 4302
      South                        LCC     SPAF 4303    SPIF 4303

  Vermont                 VT       TM      SPAF 4400    SPCS 4400

  Virginia                VA
      North                        LCC     SPAF 4501    SPCS 4501
      South                        LCC     SPAF 4502    SPCS 4502

  Washington              WA
      North                        LCC     SPAF 4601    SPAF 4601
      South                        LCC     SPAF 4602    SPAF 4602

  West Virginia           WV
      North                        LCC     SPAF 4701    SPCS 4701
      South                        LCC     SPAF 4702    SPCS 4702

  Wisconsin               WI
      North                        LCC     SPAF 4801    SPAF 4801
      Central                      LCC     SPAF 4802    SPAF 4802
      South                        LCC     SPAF 4803    SPAF 4803

  Wyoming                 WY
      East (01)                    TM      SPAF 4901    SPCS 4901
      East Central (02)            TM      SPAF 4902    SPCS 4902
      West Central (03)            TM      SPAF 4903    SPCS 4903
      West (04)                    TM      SPAF 4904    SPCS 4904

  Puerto Rico             PR       LCC     SPAF 5201    SPCS 5200

  Virgin Islands          VI       LCC     SPAF 5201    SPCS 5200
      St. Croix                    LCC     SPAF 5202    SPCS 5200

  American Samoa          AS       LCC     SPAF 5300    ---------

  Guam                    GU       PC      SPAF 5400    ---------

 See Also: {|PROJECTIONS|}SPCS
 
1	PROJECTIONS

 The following are a list of the supported projections and their
 required input.  Projections are usually categorized by the type
 of the surface the earth is projected onto:

 - cylindrical, where the projection is a cylinder wrapped around
   the globe (e.g. Mercator projection).

 - conic, where the projection is a cone placed over the globe
   (e.g. Lambert Conformal Conic projection).

 - azimuthal, where the globe is projected onto a plane (e.g.
   Stereographic projection).

 Other projections may be formed by modifying the basic types
 (e.g. pseudo-cylindrical).  The projection type is listed below 
 as the "General class" for the projection.

 In projecting a sphere (the earth) to a surface (the image), the 
 geometry of the sphere is changed.  A given projection usually 
 retains some characteristics of the sphere, usually at the expense 
 of other characteristics.  The following terms are listed below as 
 "Characteristics" for the projections where:

 - Equal-area implies a feature on one part of the map would cover
   the same area, if it also occurred on any other part of the map.

 - Conformal implies "correct form or shape".  Actually it infers
   the relative local angles about every point of the map as being
   shown correctly.  This only applies to smaller, local areas.  
   All projections distort shape for larger areas.

 - Equidistant projections show true scale between one point (or 
   two points) and every other point on the map.

 - Rectangular coordinates mean that the grid of the projection
   can be used to approximate distances, directions and areas
   of the earth surface.  Rectangular coordinates are also
   referred to as plane coordinates.

 The earth model for the projection may be defined in the MAPUNITS
 string or in the ELLIPS parameter. (See the EARTH_MODELS section.)
 Some projections can process the earth as an ellipsoid or a sphere,
 while some only process the earth as a sphere.  This is noted for
 the projection as the "Earth model:" using an "ellipsoid or sphere"
 or "sphere".  This is important if the earth model is not supported
 and is defined as values in the ELLIPS parameter:

 - For projections that use an "ellipsoid or sphere", ELLIPS may be
   a. the semi-major axis (or equatorial radius or A) for the earth
   b. the semi-minor axis (or polar radius or B) or the eccentricity
      squared.
   If the unsupported earth model is a sphere, this could be
   defined in either of the following ways:
    - do not specify a second value (i.e. only one radius is defined).
    - specify the equatorial radius again (i.e. the polar radius
      equals the equatorial radius).
    - specify the second value as zero (i.e. the eccentricity
      squared is zero).

 In general, non-azimuthal projections (i.e. cylindrical or
 conic) usually use an "ellipsoid or sphere".  If no earth 
 model is defined for a projection that uses an "ellipsoid or 
 sphere", the earth model ellipsoid defaults to E000 (i.e. 
 Clarke 1866 or NAD 1927).

 Projections that use a "sphere", will use the first value in
 ELLIPS as the radius of the earth.  If there is a second value
 defined, it is ignored.

 Azimuthal projections usually use a "sphere", but not an ellipsoid.
 If no earth model is defined for projections that use a "sphere", 
 the default will be E019 (i.e. Normal Sphere of 6370997 metres).

 The fields required for each projection are listed.  Any parameters 
 not mentioned are not used for the projection.

 Possible errors are listed for each projection.  In general any 
 of the projections will exit with E333 ("Projection was not 
 initialized"), if the required parameters for the projection were
 not specified.

2	ACEA

  Projection     : Albers Conical Equal Area
  General class  : conic
  Characteristics: equal-area
  Earth model    : ellipsoid or sphere

 Defining the MAPUNITS:
  EASI>mapunits = "acea"          | Standard name.
  EASI>mapunits = "acea e0"       | Standard name and the ellipsoid.

 Other parameters:
  EASI>prolong = "central_meridian"       | Required -+- True origin
  EASI>prolat  = "latitude_of_origin"     | Required /
  EASI>stpar1  = "1st_standard_parallel"  | Required
  EASI>stpar2  = "2nd_standard_parallel"  | Required
  EASI>efalse  = "false_easting"          | Optional, default is zero
  EASI>nfalse  = "false_northing"         | Optional, default is zero

 Possible errors:
  E332, "Equal latitudes for st. parallels on opposite sides 
         of equator" - Error encountered in initializing for the 
         projection.

2	AE

  Projection     : Azimuthal Equidistant
  General class  : azimuthal
  Characteristics: neither equal-area nor conformal
  Earth model    : sphere

 Defining the MAPUNITS:
  EASI>mapunits = "ae"           | Standard name
  EASI>mapunits = "ae e19"       | Standard name and ellipsoid

 Other parameters:
  EASI>prolong = "longitude_of_origin"    | Required -+- True origin
  EASI>prolat  = "latitude_of_origin"     | Required /
  EASI>efalse  = "false_easting"          | Optional, default is zero
  EASI>nfalse  = "false_northing"         | Optional, default is zero

 Possible errors:
  E335, "Point projects into a circle" - In converting from
         geographic coordinates to projection coordinates, 
         the point projects into a circle.
  E100, "Invalid data" - In converting from projection coordinates
         to geographic coordinates, there was an input data error

2	EC

  Projection     : Equidistant Conic
  General class  : conic
  Characteristics: equidistant
  Earth model    : ellipsoid or sphere

 Defining the MAPUNITS (Format A or B):
  EASI>mapunits = "ec"            | Standard name
  EASI>mapunits = "ec e0"         | Standard name and ellipsoid

 Other parameters (Format A, one standard parallel):
  EASI>prolong = "central_meridian"       | Required -+- True origin
  EASI>prolat  = "latitude_of_origin"     | Required /
  EASI>stpar1  = "1st_standard_parallel"  | Required
  EASI>efalse  = "false_easting"          | Optional, default is zero
  EASI>nfalse  = "false_northing"         | Optional, default is zero

 Other parameters (Format B, two standard parallels):
  EASI>prolong = "central_meridian"       | Required -+- True origin
  EASI>prolat  = "latitude_of_origin"     | Required /
  EASI>stpar1  = "1st_standard_parallel"  | Required
  EASI>stpar2  = "2nd_standard_parallel"  | Required
  EASI>efalse  = "false_easting"          | Optional, default is zero
  EASI>nfalse  = "false_northing"         | Optional, default is zero

 Possible errors:
  E332, "Equal latitudes for st. parallels on opposite sides of 
         equator " - Error occurred in initializing the projection.


2	ER

  Projection     : Equirectangular (Plate Carree)
  General class  : cylindrical
  Characteristics: neither equal-area nor conformal
  Earth model    : sphere

  Defining the MAPUNITS:
  EASI>mapunits = "er"           | Standard name
  EASI>mapunits = "er e19"       | Standard name and ellipsoid

 Other parameters:
  EASI>prolong = "central_meridian"       | Required -+- True origin
  EASI>prolat  = "latitude_of_true_scale" | Required /
  EASI>efalse  = "false_easting"          | Optional, default is zero
  EASI>nfalse  = "false_northing"         | Optional, default is zero

 Possible errors:
  E100, "Invalid data" - In converting from projection coordinates 
         to geographic coordinates, there was an input data error

2	GNO

  Projection     : Gnomonic
  General class  : azimuthal
  Characteristics: neither conformal nor equal-area
  Earth model    : sphere

 Defining the MAPUNITS:
  EASI>mapunits = "gno"                   | Standard name
  EASI>mapunits = "gno e19"               | Standard name and ellipsoid

  EASI>prolong = "longitude_of_origin"    | Required -+- True origin
  EASI>prolat  = "latitude_of_origin"     | Required /
  EASI>efalse  = "false_easting"          | Optional, default is zero
  EASI>nfalse  = "false_northing"         | Optional, default is zero

 Possible errors:
  E334, "Point cannot be projected" - In converting from geographic 
         coordinates to projection coordinates, the point projects 
         into infinity

2	GVNP

  Projection     : General Vertical Near-Side Perspective
  General class  : azimuthal
  Characteristics: neither conformal nor equal-area
  Earth model    : sphere

 Defining the MAPUNITS:
  EASI>mapunits = "gvnp"         | Standard name
  EASI>mapunits = "gvnp e19"     | Standard name and ellipsoid

 Other parameters:
  EASI>prolong = "longitude_of_origin"    | Required -+- True origin
  EASI>prolat  = "latitude_of_origin"     | Required /
  EASI>efalse  = "false_easting"          | Optional, default is zero
  EASI>nfalse  = "false_northing"         | Optional, default is zero
  EASI>pheight = "height_of_perspective"  | Usually defined,
                                          |    if defaulted is zero
 Possible errors:
  E334, "Point cannot be projected" - In converting from 
         geographic coordinates to projection coordinates, the point 
         cannot be projected.
  E100, "Invalid data" - In converting from projection coordinates 
         to geographic coordinates, there was an input data error

2	LAEA

  Projection     : Lambert Azimuthal Equal-Area
  General class  : azimuthal
  Characteristics: equal-area
  Earth model    : sphere

 Defining the MAPUNITS:
  EASI>mapunits = "laea"         | Standard name
  EASI>mapunits = "laea e19"     | Standard name and ellipsid

 Other parameters:
  EASI>prolong = "longitude_of_origin"    | Required -+- True origin
  EASI>prolat  = "latitude_of_origin"     | Required /
  EASI>efalse  = "false_easting"          | Optional, default is zero
  EASI>nfalse  = "false_northing"         | Optional, default is zero

 Possible errors:
  E335, "Point projects into a circle" - In converting from 
         geographic coordinates to projection coordinates, the 
         point projects into a circle.
  E100, "Invalid data" - In converting from projection coordinates 
         to geographic coordinates, there was an input data error

2	LCC

  Projection     : Lambert Conformal Conic
  General class  : conic
  Characteristics: conformal
                 : rectangular coordinates (U.S.A.; France)
  Earth model    : ellipsoid or sphere

 Defining the MAPUNITS:
  EASI>mapunits = "lcc"           | Standard name
  EASI>mapunits = "lcc e0"        | Standard name and ellipsoid

 Other parameters:
  EASI>prolong = "central_meridian"       | Required -+- True origin
  EASI>prolat  = "latitude_of_origin"     | Required /
  EASI>stpar1  = "1st_standard_parallel"  | Required
  EASI>stpar2  = "2nd_standard_parallel"  | Required
  EASI>efalse  = "false_easting"          | Optional, default is zero
  EASI>nfalse  = "false_northing"         | Optional, default is zero

 Possible errors:
  E332, "Equal latitudes for st. parallels on opposite sides of 
         equator" - Error occurred in initializing the projection
  E334, "Point cannot be projected" - In converting from 
         geographic coordinates to projection coordinates, the 
         point projects into infinity

2	LONG/LAT

 Geographic coordinates (not a projection).
  Earth model:  ellipsoid or sphere

 Defining the MAPUNITS:
  EASI>mapunits="long/lat"        | Standard name.  Synonyms: "lon", 
                                  |      "lat", "lat/long" or "geo"

 Other parameters: None

 Note: If a bounds is defined, it must be in geographic 
 coordinates (i.e. LONG1, LAT1, LONG2, LAT2) as there is
 no projection to convert from or to.

2	MC

  Projection     : Miller Cylindrical
  General class  : cylindrical
  Characteristics: neither equal-area nor conformal
  Earth model    : sphere

 Defining the MAPUNITS:
  EASI>mapunits = "mc"           | Standard name
  EASI>mapunits = "mc e19"       | Standard name and ellipsoid

 Other parameters:
  EASI>prolong = "central_meridian"       | Required --+- True origin
  EASI>efalse  = "false_easting"          | Optional, default is zero
  EASI>nfalse  = "false_northing"         | Optional, default is zero

2	MER

  Projection     : Mercator
  General class  : cylindrical
  Characteristics: conformal
  Earth model    : ellipsoid or sphere

 Defining the MAPUNITS:
  EASI>mapunits = "mer"           | Standard name
  EASI>mapunits = "mer e0"        | Standard name and ellipsoid

 Other parameters:
  EASI>prolong = "central_meridian"       | Required -+- True origin
  EASI>prolat  = "latitude_of_true_scale" | Required /
  EASI>efalse  = "false_easting"          | Optional, default is zero
  EASI>nfalse  = "false_northing"         | Optional, default is zero

 Possible errors:
  E334, "Point cannot be projected" - In converting from geographic 
         coordinates to projection coordinates, the transform cannot 
         be computed at the poles.

2	MSC

  Projection     : Modified Stereographic Conformal
  General class  : modified azimuthal
  Characteristics: conformal
  Earth model    : only Clarke 1866 (NAD 1927)

 Defining the MAPUNITS:
  EASI>mapunits = "msc"           | Standard name

 Other parameters:
  EASI>efalse  = "false_easting"          | Optional, default is zero
  EASI>nfalse  = "false_northing"         | Optional, default is zero

 Possible errors:
  E330, "Calculation failed to converge to a solution" - In converting 
         from projection coordinates to geographic coordinates, too 
         many iterations were made.

2	OG

  Projection     : Orthographic
  General class  : azimuthal
  Characteristics: neither conformal nor equal-area
  Earth model    : sphere

 Defining the MAPUNITS:
  EASI>mapunits = "og"           | Standard name.
  EASI>mapunits = "og e19"       | Standard name and ellipsoid

 Other parameters:
  EASI>prolong = "longitude_of_origin"    | Required -+- True origin
  EASI>prolat  = "latitude_of_origin"     | Required /
  EASI>efalse  = "false_easting"          | Optional, default is zero
  EASI>nfalse  = "false_northing"         | Optional, default is zero

 Possible errors:
  E334, "Point cannot be projected" - In converting from geographic 
         coordinates to projection 
         coordinates, the point cannot be projected.
  E100, "Invalid data" - In converting from projection coordinates 
         to geographic coordinates, there was an input data error

2	OM

  Projection     : Oblique Mercator (Hotine)
  General class  : cylindrical
  Characteristics: conformal
  Earth model    : ellipsoid or sphere

 Defining the MAPUNITS (Format A or B):
  EASI>mapunits = "om"           | Standard name
  EASI>mapunits = "om e0"        | Standard name and ellipsoid

 Other parameters (Format A):
  EASI>prolat  = "latitude_of_origin"     | Required --- True origin
  EASI>efalse  = "false_easting"          | Optional, default is zero
  EASI>nfalse  = "false_northing"         | Optional, default is zero
  EASI>scale   = "scale_at_center"        | Optional, default is one
  EASI>long1   = "longitude_central_line" | Required
  EASI>lat1    = "latitude_central_line"  | Required
  EASI>long2   = "longitude_central_line" | Required
  EASI>lat2    = "latitude_central_line"  | Required

 Other parameters (Format B):
  EASI>prolong = "longitude_of_origin"    | Required -+- True origin
  EASI>prolat  = "latitude_of_origin"     | Required /
  EASI>efalse  = "false_easting"          | Optional, default is zero
  EASI>nfalse  = "false_northing"         | Optional, default is zero
  EASI>scale   = "scale_at_center"        | Optional, default is one
  EASI>azimuth = "azimuth"                | Required, azimuth east of 
                                          |    north for central line
 Possible errors:
  E100, "Invalid data" - In initializing for the projection, there 
         was an input data error
  E334, "Point cannot be projected" - In converting from geographic 
         coordinates to projection coordinates, the point projects 
         into infinity

2	PC

  Projection     : Polyconic
  General class  : conic
  Characteristics: neither conformal nor equal-area
  Earth model    : ellipsoid or sphere

 Defining the MAPUNITS:
  EASI>mapunits = "pc"            | Standard name
  EASI>mapunits = "pc e0"         | Standard name and ellipsoid

 Other parameters:
  EASI>prolong = "central_meridian"       | Required -+- True origin
  EASI>prolat  = "latitude_of_origin"     | Required /
  EASI>efalse  = "false_easting"          | Optional, default is zero
  EASI>nfalse  = "false_northing"         | Optional, default is zero

2	PS

  Projection     : Polar Stereographic
  General class  : azimuthal
  Characteristics: conformal
  Earth model    : ellipsoid or sphere

 Defining the MAPUNITS:
  EASI>mapunits = "ps"            | Standard name
  EASI>mapunits = "ps e0"         | Standard name and ellipsoid

 Other parameters:
  EASI>prolong = "central_meridian"       | Required -+- True origin
  EASI>prolat  = "latitude_of_true_scale" | Required /
  EASI>efalse  = "false_easting"          | Optional, default is zero
  EASI>nfalse  = "false_northing"         | Optional, default is zero

2	ROB

  Projection     : Robinson
  General class  : pseudo-cylindrical
  Earth model    : sphere

 Defining the MAPUNITS:
  EASI>mapunits = "rob"                   | Standard name
  EASI>mapunits = "rob e19"               | Standard name and ellipsoid

 Other parameters:
  EASI>prolong = "central_meridian"       | Required --- True origin
  EASI>efalse  = "false_easting"          | Optional, default is zero
  EASI>nfalse  = "false_northing"         | Optional, default is zero

 Possible errors:
  E330, "Calculation failed to converge to a solution" - In converting 
         from projection coordinates to geographic coordinates, too 
         many iterations were made.

2	SG

  Projection     : Stereographic
  General class  : azimuthal
  Characteristics: conformal
  Earth model    : sphere

 Defining the MAPUNITS:
  EASI>mapunits = "sg"           | Standard name
  EASI>mapunits = "sg e19"       | Standard name and ellipsoid

 Other parameters:
  EASI>prolong = "longitude_of_origin"    | Required -+- True origin
  EASI>prolat  = "latitude_of_origin"     | Required /
  EASI>efalse  = "false_easting"          | Optional, default is zero
  EASI>nfalse  = "false_northing"         | Optional, default is zero

 Possible errors:
  E334, "Point cannot be projected" - In converting from geographic 
         coordinates to projection coordinates, the point projects 
         into infinity

2	SIN

  Projection     : Sinusoidal
  General class  : pseudo-cylindrical
  Characteristics: equal-area
  Earth model    : sphere

 Defining the MAPUNITS:
  EASI>mapunits = "sin"          | Standard name
  EASI>mapunits = "sin e19"      | Standard name and ellipsoid

 Other parameters:
  EASI>prolong = "longitude_of_origin"    | Required --- True origin
  EASI>efalse  = "false_easting"          | Optional, default is zero
  EASI>nfalse  = "false_northing"         | Optional, default is zero

 Possible errors:
  E100, "Invalid data" - In converting from projection coordinates 
         to geographic coordinates, there was an input data error

2	SOM

  Projection     : Space Oblique Mercator
  General class  : modified cylindrical
  Characteristics: basically conformal
  Earth model    : ellipsoid or sphere

 Defining the MAPUNITS:
  EASI>mapunits = "som"           | Standard name
  EASI>mapunits = "som e0"        | Standard name and ellipsoid

 Other parameters:
  EASI>lsatnum = "landsat_number"         | Required
  EASI>pathnum = "path_number"            | Required
  EASI>efalse  = "false_easting"          | Optional, default is zero
  EASI>nfalse  = "false_northing"         | Optional, default is zero

 Possible errors:
  E100, "Invalid data" - In initializing for the projection, the 
         Landsat satellite number and/or path number are out of range.
  E330, "Calculation failed to converge to a solution" - In converting 
         from projection coordinates to geographic coordinates, too 
         many iterations were made.

2	SPCS

  Projection     : State Plane Coordinate System
  Characteristics: rectangular coordinates

  Earth model:
  Only two earth models are supported for State Plane coordinates:
  - E0, Clarke 1866 (NAD 1927)
  - E8, GRS 1980    (NAD 1983)
 These may be defined in the MAPUNITS parameter or the ELLIPS 
 parameter.  If undefined, the default earth model is E0 (Clarke 1866,
 NAD 1927).  Any other earth models will be treated as an error.

 Defining the MAPUNITS: 
 
 State Plane Coordinate System coordinates require a zone number to
 be defined.  This would be defined in the MAPUNITS parameter and
 would be in the range of 0101 (or 101 for Alabama, East in the 
 following examples) to 5400 (Guam).  See the SPCS_ZONES section for
 a list of the State Plane Zones.

  EASI>mapunits = "spcs 101"      | Standard name
  EASI>mapunits = "spcs 101 e0"   | Standard name and ellipsoid

 Other parameters:

 Depending on the defined (or default) earth model, PROSET will
 require a text file that is normally stored in /pci/etc on UNIX
 platforms.  (The search path may be different, depending on the
 platform.)  If these files are there, the NAD1927 and/or NAD1983 
 parameters may be defaulted, in which case PROSET should be able 
 to find them.  (PROSET uses the WDFF parameter, substituting "etc"
 for "wdb" (or "ETC" for "WDB"), to make up the search path.)  If 
 the pci account is not in for example /pci the text files would not 
 be found and the program would exit.  In any case the search path 
 and filename can be explicitly defined with the NAD1927 and NAD1983
 parameters.

  EASI>nad1927 = "nad1927_text_file"
  EASI>nad1983 = "nad1983_text_file"

 Possible errors:
  E331, "Invalid earth model defined for the projection" - In setting 
         up for the projection, the earth model is not E0 (Clarke 
         1866, NAD 1927) or E8 (GRS 1980, NAD 1983).
  E100, "Invalid data" - In setting up for the projection, an invalid 
         State Plane zone was entered.
  E328, "No zone was defined or could be derived for the projection" -
         In setting up for the projection, the State Plane zone
         was not specified in MAPUNITS.

 See Also: {|}SPCS ZONES

2	TM

  Projection     : Transverse Mercator (Gauss-Krueger)
  General class  : cylindrical
  Characteristics: conformal
                 : rectangular coordinates (U.S.A.; Britain)
  Earth model    : ellipsoid or sphere 

 Defining the MAPUNITS:
  EASI>mapunits = "tm"            | Standard name
  EASI>mapunits = "tm e0"         | Standard name and ellipsoid

 Other parameters:
  EASI>prolong = "central_meridian"       | Required -+- True origin
  EASI>prolat  = "latitude_of_origin"     | Required /
  EASI>efalse  = "false_easting"          | Optional, default is zero
  EASI>nfalse  = "false_northing"         | Optional, default is zero
  EASI>scale   = "scale_at_cent_meridian" | Optional, default is one

 Possible errors:
  E334, "Point cannot be projected" - In converting from geographic 
         coordinates to projection coordinates, the point projects 
         into infinity
  E330, "Calculation failed to converge to a solution" - In converting 
         from projection coordinates to geographic coordinates, the 
         conversion failed to converge to a solution

@pagebreak

2	UPS

  Projection     : Universal Polar Stereographic
  General class  : azimuthal
  Characteristics: conformal
                 : rectangular coordinates
  Earth model    : only supported ellipsoids or spheres
                   (i.e. E000 to E019)

 Universal Polar Stereographic projection requires a zone to be
 specified or a sample point in geographic coordinates from which
 a zone can be derived.  If a zone is specified it would be in
 the MAPUNITS string.  Any of the following are valid:

 Defining the MAPUNITS:
  EASI>mapunits="ups z"           | Standard name and zone
  EASI>mapunits="ups z e0"        | Standard name, zone, and ellipsoid

 If the zone is not defined in the MAPUNITS string, a sample
 point can be input with PROLONG and PROLAT.  For example:

  EASI>mapunits = "ups"
  EASI>prolong  = "117 w"
  EASI>prolat   = " 84 n"

 If the UPS zone, PROLONG and PROLAT are not defined, but (BX1
 and BY1) or (BX2 and BY2) define 'LONG/LAT' point(s), one of
 these can be used to derive the UPS zone.  (If both (BX1 and 
 BY1) and (BX2 and BY2) are defined, (BX1 and BY1) is used.)

 If the UPS zone is derived from a sample point and the longitude
 for the point is shared between zones, the eastern-most zone is
 returned.  For example, if prolong="0 w" and prolat="84 n", the 
 assumed zone is UPS zone Z, not UPS zone Y.  Any confusion can 
 be avoided, by picking a sample point in the zone and not on the 
 zone border.

 Other parameters: None

 Possible errors:
  E331, "Invalid earth model defined for the projection"
       - In setting up for the projection, the earth model is
         not in the range of E0 to E19 and is defined explicitly
         with the ELLIPS parameter.
  E108, "Option not available"
       - In setting up for the projection, the UPS zone is 
         not A, B, Y or Z.

2	UTM

  Projection     : Universal Transverse Mercator
  General class  : cylindrical
  Characteristics: conformal
                 : rectangular coordinates
  Earth model    : only supported ellipsoids or spheres
                   (i.e. E000 to E019)

 Universal Transverse Mercator projection requires a zone to be
 specified or a sample point in geographic coordinates from which
 a zone can be derived.  Once the zone is known, the central 
 meridian can be derived for the zone.  If a zone is specified 
 it would be in MAPUNITS string.  Any of the following are valid:

 Defining the MAPUNITS:
  EASI>mapunits="utm 11"          | Standard name and zone
  EASI>mapunits="utm 11 m"        | Standard name, zone and row
  EASI>mapunits="utm 11 m e0"     | Standard name, zone, row and ellipsoid

 If the zone is not defined in the MAPUNITS string, a sample
 point can be input with PROLONG and PROLAT.  For example:

  EASI>mapunits = "utm"
  EASI>prolong  = "117 w"
  EASI>prolat   = " 33 n"

 If the UTM zone, PROLONG and PROLAT are not defined, but (BX1
 and BY1) or (BX2 and BY2) define 'LONG/LAT' point(s), one of
 these can be used to derive the UTM zone.  (If both (BX1 and 
 BY1) and (BX2 and BY2) are defined, (BX1 and BY1) is used.)

 If the UTM zone is derived from a sample point and the longitude
 for the point is shared between zones, the eastern-most zone is
 returned.  For example, if prolong="174w", the assumed zone is
 UTM zone 2, not UTM zone 1.  Any confusion can be avoided, by 
 picking a sample point in the zone and not on the zone border.

 Other parameters: None

 Possible errors:
  E331, "Invalid earth model defined for the projection"
        - In setting up for the projection, the earth model is
          not in the range of E0 to E19 and is defined explicitly
          with the ELLIPS parameter.
  E309, "Range mistake (might be syntax or range)"
        - In setting up for the projection, the UTM zone is 
          outside the range of 1 to 60
  E328, "No zone was defined or could be derived for the projection"
        - In setting up for the projection, the UTM zone was not
          specified in MAPUNITS.

2	VDG

  Projection     : Van der Grinten
  General class  : miscellaneous
  Characteristics: neither equal-area nor conformal
  Earth model    : sphere 

 Defining the MAPUNITS:
  EASI>mapunits = "vdg"          | Standard name
  EASI>mapunits = "vdg e19"      | Standard name and ellipsoid

 Other parameters:
  EASI>prolong = "central_meridian"       | Required --- True origin
  EASI>efalse  = "false_easting"          | Optional, default is zero
  EASI>nfalse  = "false_northing"         | Optional, default is zero

1	REFERENCES

  Robinson, A.H., Sale, R.D., Morrison, J.L., and Muehrcke, P.C.,
  "Elements of Cartography (5th Ed.)", John Wiley and Sons,
  New York, 1984.

  Snyder, John P., "Map Projections - A Working Manual", U.S.G.S. 
  Professional Paper 1395, U.S. Geological Survey, 
  Reston, Virginia, 1987.

  "Software Documentation for GCTP, General Cartographic 
  Transformation Package", U.S. Geological Survey, National Mapping
  Division, Reston, Virginia, 1990 (Unpublished).
