Q: When
translating a point in Puerto Rico I get a message that says “point
out of bounds in VERTCON (-29)”. What is the
problem?
A: Corpscon, like Vertcon, only works for
vertical conversions in the continuous United States (lower 48).
This messages tells you that you are outside this
boundary.
Q: I am getting an error
when I try to load the corpscon_complete.exe on a Windows 2000
computer. It tells me to check some type of access. Can you tell me
what might be wrong?
A: The program is making sure
you have administrator privileges for correct
installation.
Q: Will Corpscon convert
from/to geographic coordinates to UTM in Canada?
A:
Good question. We have only tested it for conversions within the US.
Since the parameters for UTM conversions are for North America,
Corpscon should work. Try the program on some known control points
that have values listed in UTM and lat, long.
Q: Is there a reason that the Corpscon has the
fixed decimal places (3 places) in the output? Is there a way to
change the decimal places? Can we add the function to change the
decimal places in a future release?
A: Corpscon has
fixed decimal places in the output to prevent people from
overestimating the accuracy. Conversions between some datums and
some coordinate systems are not exact, only extrapolated between
known points.
Q: I downloaded the
most current version of Corpscon and am wondering if its possible to
convert decimal degrees data taken in WGS84 to State Plane NAD 27
Alaska Zone 1 using this software. I tried running the program and
didn't seem to find the option for WGS 84.
A:
Corpscon only converts from NAD83 to NAD27 and reverse since it's
based on NGS's NADCON. However the definition of NAD83 is close to
WGS84 and therefore some will use NAD83 as WGS84. Be aware that is
some cases the differences between NAD83 and WGS84 coordinates can
differ as much as a meter.
Q: In
the last version of Corpscon (5.xx) in the user defined file, you
could specify up to 6 fields of input and output. This morning I
have only been able to define 4 fields (and I would like to have
just one more). I found myself reading the instructions and working
through them, but I couldn’t figure out how to do more than 4. Is
there a way to define more than the 4?
A: In the new
version, you only have to specify where the following fields are in
the input file: Point Name, Lat, Long, and Elevation (if performing
a vertical conversion). The remaining fields are carried over to the
output file. For example, you have an input file with ptnumber,
ptname, lat, long, elevation, field_code, and attribute. You would
specify in the input side that the ptname is in field 2, the lat is
in field 3, long in field 4 and elevation is in field 5. On the
output side you specify the order of how you would like the
converted coordinates and the input fields by specifying the number
for each. So if you want the same order as above you specify ptname
is field 2, coord_x is field 3, coord_y is field 4, elevation is
field 5, Input Field 1 is field 1, Input Field 6 is field 6 and
Input Field 7 is field 7.
Q: How do
I get a copy of the Users guide for Using the Corpscon DLL in other
applications?
A: Click here to view or download the pdf
document.
Q: What are the
Scale Factor and Combined Factor?
A: The State Plane
Coordinate System (SPCS) is distorted, as are all projections.
Dividing a distance between two points on the SPCS by the scale
factor provides an approximation of the real distance, i.e., the
distance measured on the ellipsoid, the surface a GPS works
with.
A better approximation is the combined scale factor
(combined factor). Dividing a SPCS distance by the combined scale
factor approximates the length of a cord connecting the two
points.
Scale factor is the ratio of an incremental distance
measured on the ellipsoid to the distance on the State Plane grid,
whereas combined scale factor is the ratio of the former distance to
the distance on the ground.
Q: I input a
location in latitude/longitude. Why is the answer off by tens of
degrees?
A: Input longitude must be positive. East
is east and west is west, except for Corpscon, where west is east.
Try again, without the "-".
Q: Does
CORPSCON convert coordinates from/to UTM Zone 20 (Eastern Puerto
Rico)?
A: No, CORPSCON does not include conversions
from/to UTM Zone 20 (Eastern Puerto Rico).
Q: I have tried to download CORPSCON several times,
but it takes too long or the procedure times out. Can you send me it
on CD or disk?
A: No, CORPSCON is only available via
this Web site. If you have problems with the standard version (~10
MB), try downloading the minimum version and the VERTCON and geoid
files separately.
Q: Does CORPSCON
convert from / to the WGS 84 datum?
A: No, CORPSCON
does not convert from / to the WGS 84 datum. For most applications
that CORPSCON is used for, NAD 83 is close enough. TEC has developed
a program called GeoTrans which the National Imagery and Mapping Agency (NIMA) now
maintains. GeoTrans transforms between local geodetic datums and WGS
84.
Q: When I convert latitude,
longitude to State Plane or UTM coordinates I get the error message
"Could not be converted by NADCON", Why?
A: 1.
Check to make sure that the longitude value(s) are positive.
CORPSCON does not accept negative longitude values.
2. Are you in
Alaska or Hawaii or Virgin Islands or Puerto Rico? Makes sure you
have downloaded the files needed for these areas.
3. If you are
using an input file, make sure that there is a carriage return after
the last line of data in the file.
Q:
Will CORPSCON work outside of the Continental US, Alaska, Hawaii,
Virgin Islands or Puerto Rico?
A: No, CORPSCON was
only developed to work in these areas listed above. GeoTrans will do conversions in these areas, but
does not support State Plane Coordinates or
NADCON.
Q: When converting a single
point or a list of points using CORPSCON, I get a error message
"Can’t open temp file for writing in CMSinglePoint()" or
the error message "Can’t open temp file for writing in
CMUserDefinedFile()" Why?
A: Make sure that CORPSCON was
installed correctly (i.e. went through the install procedure) and
not just copied from another computer or directory. CORPSCON places
a file (Corpscon.ini) in the C:\Windows directory during
installation which tells the software where (under what directory
structure) it was installed.
Q: Does
Corpscon have a limit on the number of points it can convert from a
file?
A: No. Corpscon does not have a limit.
However, you must have enough hard disk space for Corpscon to create
a temporary file as well as your output file. For example, if your
input file is 10MB, then you will need a minimum of 20MB of free
hard disk space to perform the conversion.
Q: I would like to get a copy of the source code
for CORPSCON. How do I get it?
A: CORPSCON is based
on the NADCON and VERTCON algorithms developed by the National Geodetic
Survey (NGS). The source code for NADCON and VERTCON is
available on the NGS Homepage (
www.ngs.noaa.gov/PC_PROD/pc_prod.shtml)
Q: When I use the User Defined Input File to
convert a text file containing latitude, longitudes or northing,
easting coordinate values with other information (i.e. point name,
elevation, feature code,…) after converting I only get a file with
some header information in it. What happened? (Version 5.x
only)
A: Make sure that you specified the User
Defined Input File Field Specifications the same as your input file.
Example:
Input file contains:
Point name, Latitude, Longitude, Elevation, Feature Code
Make sure the User Defined Input File Field Specifications are
set-up as:
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