
                           NMAP2 Data Access Configuration 


NOTE:  The following information is of use to site administrators and others 
       having responsibility for managing NMAP2 data access.

The types of data available for display in NMAP2 may be controlled in large 
part by a set of tables and rules governing the use of those tables.  In 
addition, the display options for the various data types are largely table 
driven.  Display options include the choice of station plotting model for 
observational data types, the choice of fields and contouring options 
(restore files) for model data, and the default time line characteristics such 
as time span, number of frames, etc.  The intent of this help is to provide 
the necessary information so that site administrators can properly manage NMAP2 
data access and display options.

The information in this help is presented from the perspective of how the
"Data Selection" window interacts with the various tables . The 
"Data Selection" window uses the "Data Source" and time line GUIs to specify a 
loop's data sets and time controls, respectively.  The ways in which the 
"Data Source" window and time line are constructed are a function of data type 
and several tables that can be configured by the site administrator.  

The top-level categories that appear in the "Data Source" window, i.e.,
"IMAGE", SURF_OBS", "SURF_FCST",  "UAIR_OBS", "GRID", "VGF", "MISC" are 
hard-coded.  A data type must fall under one of these categories to be
displayed in NMAP2.  

For the purposes of this description the top-level scroll list that appears
in the "Data Source" window is referred to as layer 1, the next layer as the 
GUI expands is referred to as layer 2, and so on.  The number of layers and the 
contents of each layer scroll list are a function of data category and several 
tables.  

The following sections describe the "Data Source" window layers for each 
top-level data category.  At the beginning of each section a table is given 
which lists each layer, its description, the $GEMTBL table name and columns 
used to construct the layer, and an example layer name.  Then the rules 
governing the use of the tables are given.  Finally, the rules governing the 
construction of the time line are given at the end of each section assuming 
that the data type is dominant.

I.  Image Data Sources (IMAGE)

Layer#  Description			Table/Columns		Example
------------------------------------------------------------------------
1	Data Source Name		Hard Coded		IMAGE
2	Image Type			datatype.tbl, cols 1,4	SAT
3	Top-Level Image Type directory	N/A			GOES-E
4	Sub-directory			N/A			Atlantic
5	Sub-directory			N/A			IR	

For image data sources, layer 2 of the "Data Source" window lists the available
image types, currently SAT for satellite images, and RAD for radar images.  
These image types are obtained from the table $GEMTBL/config/datatype.tbl table 
using the SAT and RAD file type entries that correspond to the category type 
CAT_IMG in the 4th column of the table.  Subsequent "Data Source" layers 
correspond to directories that fall under the directory tree specified by the 
environment variable in the 2nd column in the table and are generated 
automatically.  Thus, the number of layers depends on the number of 
sub-directories in the data base.  The maximum number of sub-directories that 
can be supported is ten.

The time line frame times are obtained from the image file names.  The number of
selected times and total time span are obtained from the DEF # FRM and DEF RANGE
columns, respectively, in the datatype.tbl.

II.  Observational Data Sources (SURF_OBS, UAIR_OBS)

Layer#  Description                     Table/Columns           Example
------------------------------------------------------------------------
1	Data Source Name		Hard Coded		SURF_OBS
2	Observation Data Type		datatype.tbl, cols 1,4	METAR
3	Station Plotting Model Name	prmlst.tbl, cols 1,2	standard	

For observational data sources, layer 2 of the "Data Source" window presents the
available data types in the data base.  These data types are determined from 
the table $GEMTBL/config/datatype.tbl.  For the SURF_OBS category, the data 
type choices that appear in the layer 2 scroll list, e.g., METAR, SYNOP, etc., 
are obtained from all first column entries in the table that match the category 
CAT_SFC in 4th column of the table.  Likewise, for UAIR_OBS the data type 
choices for the layer 2 scroll list are obtained from all first column entries 
that match the category CAT_SND in the 4th column of the table.  The layer 3 
scroll list presents the available station plotting models for each data type.  
The station plotting models are obtained from the table 
$GEMTBL/config/prmlst.tbl.  See this table for a description of how station
plotting models are specified.  All available station models for a data type, 
e.g, WINTER, are listed for that data type, e.g., METAR.  For each station 
model in the table, the station model name appears in the first column, 
preceded by a "^",  and the data type appears in the second column.  When
the station model name is the same as the data type, the word "standard"
appears in layer 3. 

The time line is constructed by opening the latest data files that match the 
template specified in the 3rd column of the datatype.tbl for the selected data 
type.  The available frame times and time increments are read from the data 
files.  The time line span and default number of frames selected are obtained 
from the DEF RANGE and DEF # FRM, columns of the datatype table, respectively. 

III.  Surface Forecast Data Sources (SURF_FCST)

Layer#  Description                     Table/Columns           Example
------------------------------------------------------------------------
1       Data Source Name                Hard Coded              SURF_FCST
2	Surface Forecast Data Set Name	datatype.tbl, cols 1,4	MRFMOS
3	Cycle Time, from template	datatype.tbl, cols 2,3	020305_1200
4	Station Plotting Model Name	prmlst.tbl, cols 1,2	climo_mm	 

Layer 2 of the "Data Source" window lists the surface forecast data set
names which are obtained from $GEMTBL/config/datatype.tbl.  All first column 
entries that match CAT_SFF in the 4th column are listed in the scroll list.  
Layer 3 lists the available cycle times.  The cycle times are determined by the
files in the directory specified in column 2 that match the template in
column 3 of the table.  Layer 4 lists the station plotting model names.  These
are obtained from the $GEMTBL/config/prmlst.tbl.   

The time line is constructed by opening the surface forecast data file that
matches the template in the 3rd column of the datatype.tbl using the user-
selected cycle time.  The forecast valid times are read from the surface 
forecast data file and selected by default for loading.

IV.  Grid Data Sources (GRID)

Layer#  Description                     Table/Columns           Example
------------------------------------------------------------------------
1 	Data Source Name		Hard Coded		GRID
2	Model Name			datatype.tbl, cols 1,4	avn	
3	Cycle Time, from template	datatype.tbl, cols 2,3	020305_1200
4	Product Group Name		mod_res.tbl, cols 3,4	basic_wx	
5	Product Name			mod_res.tbl, cols 1,4	PRECIP_TYPE	

Layer 2 of the "Data Source" window presents the model data names, 
e.g., AVN, ETA, etc. in the data base.  These are determined from all first 
column entries in the table $GEMTBL/config/datatype.tbl that match CAT_GRD in
the 4th column of the table and have at least one corresponding entry in the
4th column of $GEMTBL/nmap/mod_res.tbl.  Layer 3 presents the list of 
available cycle times for the model selected.  The cycle times are determined 
by the file names that match the template in the datatype.tbl.  Layer 4 
presents the product groups, e.g., standard, basic_wx, etc., that are 
available for each model.  These are obtained from the mod_res.tbl table.  All 
group names in the third column of mod_res.tbl are listed that match the 
selected model specified in the 4th column of that table.  Layer 5 lists all 
the product names, e.g, 500mb_HGHT_WIND, that correspond to the product group.  
The product names, which are specified in the first column of the table, 
correspond to a specific NMAP restore file.

The time line is constructed by opening the model data file that matches the
template in the 3rd column of the datatype.tbl, using the user-selected cycle 
time.  The forecast valid times are read from the model data file and selected 
by default for loading.

V.  VGF Data Source (VGF)

Layer#  Description                     Table/Columns           Example
------------------------------------------------------------------------
1 	Data Source Name		Hard Coded		VGF
2	VGF Group Name			vgf.nmap, col 1		bawx
3	VGF Name, from directory list	vgf.nmap, col 2		rnsnow.vgf

VGF product group names are listed in layer 2 of the "Data Source" window.  
These are obtained from the first column of the table $GEMTBL/nmap/vgf.nmap.  
They correspond to directories where VGFs are stored.  Layer 3 lists the VGFs 
for the selected product group.

The time line uses the system clock time rounded to the nearest hour for the
selected frame time. 

VI.  Miscellaneous Data Sources (MISC)

Layer#  Description                     Table/Columns           Example
------------------------------------------------------------------------
1       Data Source Name                Hard Coded              MISC
2	Misc. Data Set Name		datatype.tbl, col 1 	AIRM

Miscellaneous data sources obtain their level 2 names from the data set 
alias (file type) names given in column 1 of the $GEMTBL/config/datatype.tbl
table.  All first column entries that match CAT_MSC in the 4th column are
listed in the scroll list. 

The time line is constructed using the default range and interval specified
in the datatype.tbl, DEF RANGE and DEF INTRVL columns (7,8), respectively.
The number of frames is computed using these values and all frames are 
selected by default for loading.  The path and template specified in 
the datatype.tbl, columns 2 and 3, respectively, are used to open the
appropriate files.

