home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Joint Education Initiative
/
Joint Education Initiative.iso
/
programs
/
dos
/
gna
/
help.txt
< prev
next >
Wrap
Text File
|
1990-05-16
|
15KB
|
315 lines
*PANEL1
Access options by using an "arrow" key followed by the ENTER key or by
simply typing the first letter of the menu choice (for example, if you
type "P", you will enter the Point Data option). Menu choices are:
IMAGE - create color screen pictures of topography, magnetics, gravity,
satellite imagery, or data from a user-defined grid. After selecting a data
set, select a color palette option (which includes a stored system default,
a stored user default, and a temporary user set).
AREA - define the geographic area-of-interest. Since each data set has a
different resolution (30-second to 10-minute) and different completeness of
coverage, IT IS STRONGLY RECOMMENDED THAT WHEN VIEWING AN IMAGE, THE IMAGE
OPTION IS SPECIFIED BEFORE AREA OPTION. To select an area, the user must
type in latitude and longitude limits or graphically overlay a window on
the
data.
POINT DATA - display earthquake, crustal stress, or thermal aspect data on
the screen. Selection options include parameters unique to the data type,
as well as symbol and color choices.
CONTOURS - display contours that have been pre-computed and stored on the
compact disc. These include topography, magnetics and gravity. Options
exist in sub-menus to select intervals and colors.
BOUNDARIES - reference overlays for examining displayed data. Choices are
coastlines (which include country borders), state and county borders, and
latitude - longitude grids.
GO - an action command to display (or re-display) the data you have
selected.
SCREEN -allows the user to: (1) title a display, (2) save a display, (3)
restore a previously saved display, or (4) clear currently active display
parameters.
EXIT - returns the user to the Main Menu.
*PANEL2
Chose the data image that will appear as a color picture on the screen.
Upon selecting a data type, the user will be provided with options for the
color palette. To change a color palette after an image has been drawn,
simply re-enter this menu item, confirm your data type, and choose a new
palette option. Greater detail on all of the following data sets can be
found in "DOC" files on the CD- ROM (see Introduction on first screen or
the User Manual).
Topography (N. America) - display land and marine topography (in meters)
using a 5-minute grid.
Topography (U.S. - Land/Coast) - designed especially for this CD- ROM. This
contains a land 30-second data grid with coverage for the conterminous
United States that has been masked to delete offshore values. (Note: The
masking deleted historical errors in this popular file.) Thirty-second
coastal bathymetry was added to this file. All data are in meters.
Caution: Inland waters have some datum shifts. For example, most of the
Great Lakes are at elevations of 560-600 feet, and a depth of 10 feet may
represent an elevation of 590 feet above sea level.
DNAG Magnetics - magnetic data for much of North America (excluding Mexico)
on a 2.5-minute grid. The grid was developed from four separate 2-km grids
used to generate the Decade of North American Geology maps of the Geological
Society of America.
MAGSAT Magnetics - a smoothed 2.5-minute grid generated from a 2- degree
file. The smaller grid was chosen to facilitate comparisons with the other
data sets.
DNAG Gravity - a combination of Bouguer anomalies on land and free- air
anomalies over water environments. The 2.5-minute grid was developed from
a
6-km grid used on Decade of North American Geology maps.
Isostatic Gravity - a 2.5-minute grid developed from a 4-km grid of data for
conterminous United States.
Satellite Imagery - weekly composite values at a 10-minute grid for summer
1986 ("Julian" days 162-168) and fall 1986 ("Julian" days 316-322). AVHRR
channels 1, 2 and 5 (representing visible, reflected infrared and thermal
infrared, respectively) and computed normalized vegetation indexes are
presented.
User File - a file unique to an individual user. See the Technical
Specifications chapter and the Running Utilities appendix in the User Manual
for details on grid structure requirements.
*PANEL3
The user has several choices when choosing color representation on an image.
Default values for each data type come with the software. The user can
temporarily alter the system default values for use during the session or
redefine and save new defaults for future use. A restore command is
available to re-initialize the system defaults.
*PANEL4
Specify a geographical area-of-interest. It is recommended that a user
first choose a data type before selecting a geographical area; however, this
is not mandatory.
First select either a specific NEW area (anything other than the entire
limits of the data set) or ALL (the entire data set).
If a new area is requested, one may ENTER LIMITS by typing the latitude and
longitude, or use a graphical WINDOW IMAGE with a movable rectangle overlaid
on an image of the selected data.
IMPORTANT NOTE: When using the WINDOW IMAGE, the rectangle that first
appears is the exact dimensions of the area that will fill your screen at
maximum resolution. Selecting a smaller area will result in an image that
is smaller than the screen (which can be expanded by zoom features -- such
as "Page-Up" -- discussed in the User Manual). Because each data type
represents a different grid resolution, specifying the area limits before
the data type can result in very small, "postage stamp"-like images.
*PANEL5
If one chooses to ENTER LIMITS, the user specifies degrees and decimal
degrees at the prompts. All of the data sets are in the Northern
Hemisphere. The left-most limit (170 E) is near the International Date Line
and the right-most limit (10 W) is near the Prime Meridian.
*PANEL6
The POINT data sets are lithospheric data whose values may be represented
by
symbols on the screen at distinct locations. The user can define symbols
and colors to highlight specific attributes of the data in the display.
Each of these lithospheric data sets were developed in support of maps
associated with the Decade of North American Geology project sponsored by
the Geological Society of America.
EARTHQUAKES summarize earth seismicity data FROM 1534 through 1985.
STRESS is directional information relating to crustal stress measurements.
THERMAL ASPECTS data contain heat flow and thermal gradient values.
VIEW MENU returns the user to the main View Menu.
*PANEL7
When selecting EARTHQUAKES, choose symbols and colors for the ranges of
dates and magnitudes desired. One may use different symbols and colors for
different ranges. For example, each year or each magnitude range could have
different colors and symbols.
Earthquake data covers the time period from 1534-1985 and magnitude values
from 2.50 to 8.70.
If ranges are specified for both dates and magnitudes, only events which
satisfy both ranges will be retrieved.
*PANEL8
CRUSTAL STRESS data can be selected by choosing a range of azimuth, from 0
to 180. Also, a stress type can be specified from an acceptable value
table, or all types can be selected. Quality constraints can be imposed to
specify the minimum and maximum quality accepted. The stress qualities
range from A (best) to D (worst), with E (unknown). For each search the
user can specify colors to be associated with a directional symbol. By
repeating the selection process, different selections can receive unique
colors.
If ranges are specified for more than one parameter, only data satisfying
all ranges will be retrieved.
*PANEL9
THERMAL ASPECTS data lets you display either heat flow ranges or thermal
gradients or both with a variety of symbols and colors. In addition,
minimum and maximum quality constraints can be given. The quality of
thermal data ranges from 1 (+/- 5%) to 6 (no quality given).
If ranges are specified for more than one parameter, only data satisfying
all ranges will be retrieved.
*PANEL10
CLEAR FIELDS lets you erase previously selected parameters. One must erase
each of the point data sets individually.
VIEW MENU returns the user to the main View Menu. Once in the View Menu,
the user can continue selecting additional overlay display features, display
the current image, or select other options.
*PANEL11
BOUNDARY SELECTION - overlays geo-political reference data onto other data
layers. In each selection the user can specify colors.
COASTLINE plots shore and lake information, as well as international
boundaries. There are two options available:
GENERAL - is a generalized data file which plots quickly and is
adequate for most large displays (e.g., country-wide).
DETAIL - is a finer resolution data set which should be used for
displays of regions that are much smaller than a country.
STATES & PROVINCES displays political subdivisions within individual
countries. This file does not duplicate the country boundary information
used in the coastline file; therefore, it is recommended that COASTLINE
always be used with this option.
U.S. COUNTIES will plot county information for the United States. The state
boundaries are not included in this file; therefor, it is recommended that
STATES & PROVINCES always be used in conjunction with this option.
LAT/LONG GRID lets the user superimpose a latitude/longitude grid on top of
the image. Options exist to choose specific grid intervals. The grid may
be added or removed during the display by using "CTRL-G".
*PANEL12
The SCREEN option provides screen utilities. The options are:
RESTORE - recall a previously saved screen from your hard disk.
SAVE - file a screen image on hard disk for future use. The file name
must be 8 characters or less with no extension.
CLEAR SCREEN - erase all selection parameters at once and continue
with a new selection session.
TITLE - label a display. The title must contain 80-characters or
less.
VIEW MENU - return to the main View Menu.
*PANEL 13
The CONTOUR OVERLAY SELECTION menu permits the user to specify data sets
which have contours stored on the CD-ROM. The user may choose color
presentation of contours from a color palette; additionally, a selection can
be made for the contour interval.
Each of the data sets presented on this screen correspond to an unlabeled
vector file on the CD-ROM. An important constraint on the contour intervals
is the recorded resolution. Topography data, for example, have been
contoured at 200-foot intervals. Selecting 400-foot intervals plots every
other stored line; selecting 1000-foot intervals plots every fifth line.
The software algorithm always normalizes the data about the zero-
contour interval. Therefore, if a 40 mgal contour interval was
selected, the contours would include ...-80, -40, 0, 40, 80....
The TOPOGRAPHY contours were developed from a 5-minute average elevation
file which covers all of North America. A contour interval of 200 feet was
used.
The ISOSTATIC GRAVITY contours, developed by the U. S. Geological Survey,
only contain data for the United States. A contour interval of 10 mgals was
generated from a modified, projected grid that was developed by the
Cooperative Institutions for Geoscience Data Management and Applications
(CIGMA).
The Decade of North American Geology (DNAG) GRAVITY project compiled a
gravity data set that covers most of North America. The DNAG gravity
set was developed on a 6-km grid and includes free-air anomalies on
oceans and Bouguer anomalies on land. Gravity contours are at 20 mgal
intervals.
The Decade of North American Geology (DNAG) MAGNETICS project compiled a
magnetic data set that covers most of North America. The DNAG magnetics
set was developed on a 4-km grid. Magnetic contours have been stored at
200 gamma (nT) intervals.
COASTLINE data is provided on the CD-ROM as a reference overlay for
the geophysical data.
STATE & PROVINCE outlines are available for U.S. and Mexican
states, as well as Canadian provinces.
U.S. COUNTIES are available for those who wish to see higher base
reference resolution for the conterminous U.S.
*BOXEGA
KEY ACTION (box movements)
Up Arrow Move North
Left Arrow Move West
Right Arrow Move East
Down Arrow Move South
KEY ACTION (box size) KEY ACTION(box size)
t Shrink top T Grow top
b Shrink bottom B Grow bottom
l Shrink left L Grow left
r Shrink right R Grow right
KEY ACTION
PgUp Increase box size in all directions
PgDn Decrease box size in all directions
- Decrease action step size
+ Increase action step size
CR Select current screen box coordinates
and EXIT geographic select routine
Esc Abort current selection; go to Main Menu
IF DEFAULT WINDOW SIZE IS : | DATA | PLOT | ENLARGE
| RESOLUTION | TIME* | FUNCTION
----------------------------------------------------------------
Unchanged | Full | 2 min | available
Enlarged | Decimated | >2 min | unavailable
Shrunk | Full | <2 min | available
* plot time for 286-8 mhz (386-25 mhz = 50 seconds)
*GO
Display (or re-display) the data that have been selected on the screen.
This includes image, point, contour, and boundary data with the appropriate
colors and symbols that have been selected. If no changes have been made
since the last screen was displayed for this session, the screen image will
be quickly re-displayed from memory. If any changes or additions have been
made, the changed data will be read from the CD-ROM and the new image will
display data slower rate.
Once the image has been created on the screen, there are a number of options
available for on-screen data manipulation. These are:
Ctrl-G Geographic latitude-longitude grid overlay; off/on switch
Ctrl-P Cross section profile
Ctrl-T Display title of screen image; off/on switch
Ctrl-V Point value display function
F3 key Display color scale; off/on switch
PgUp Zoom in on lower left quadrant of screen
PgDn Zoom out
ESC Return to View Menu
Enter Return to View Menu
*EXIT
Leave the View Menu and return to the Main menu. If the user has not done
a
screen save, the image that one created during this view session will be
lost. From the Main Menu, one may run the Tutorial, or return to this menu
to view data.