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<title>Standard Format</title>
<h1>Help on Standard Format</h1>
<h2>The Advanced Missile Signature Center Standard File Format</h2>
<b>Version 2.0<p>
Amended 1995 November 3</b><p>
<b>Philosophy</b><p>
The Advanced Missile Signature Center (AMSC) standard archive format (SAF) was
created for flexible and extensible use in data archiving.
Although the data may be ascii or
one of several binary formats, the file header is plain
ascii text and therefore human readable.<p>
The "magic number" for identifying SAF files is the case-insensitive
string: "HdSize ". Therefore, no naming conventions are required,
and computer programs can easily identify the the file format.<p>
Both image and non-image data may be stored in the AMSC standard
archive format. The type of data is identified by information
stored in the header.<p>
<b>Header Format</b><p>
The standard header is ASCII text consisting of tags, or field
identifiers, followed by data fields. The number of tags used in
any particular header is variable dependent on the available
purtenant information. Additional header information
can be added when required with an associated increase in header
size. Tags and associated data fields may be listed in any order,
except for the HdSize tag which is listed first and identifies the
file as a Standard Archive Format file. <p>
Each tag consist of several characters, followed by a space.
The tag names and values are case insensitive.
Data display and analysis programs can search the header
for standard tags and treat the data appropriately.<p>
<pre>
Header Item Advanced Missile Signature Center Requirements
Line Termination LF or CR/LF. HdSize byte count must include
the CR and LF characters.
HdSize Exact number of header bytes, or the word "auto".
If "auto" is used, then the last tag in the header
must be "data".
Tag Names All standard tags are six characters or less. User
defined tags may be from one to 29 characters.
Data Fields Variable length with ascii text. Leading and trailing
spaces are ignored. Different parameters may have
values which are text, integers, or floating point
numbers.
NumDPs Number of points per parameter in a POD file. If the
value is "auto", the value will be determined from the
size of the file for binary data, of from the number of
line feeds for ascii data.
PnSize Existence indicator of parameter names in POD files.
A non-zero value indicates that the first line following
the header consists of parameter names. Each name must
be less than 64 characters long. Embedded spaces are
permitted if the name is enclosed in quotes. This tag
may be left out of the header if the value is zero.
PuSize Existence indicator of parameter units in POD files.
A non-zero value indicates that the first line following
the (possibly) parameter names is a line of unit names.
Each unit name must be less than 64 characters long.
Embedded spaces are permitted if the name is enclosed
in quotes. This tag may be left out of the header if
the value is zero.
PcSize Existence indicator of parameter classifications in POD
files. A non-zero value indicates that the first line
following the (possibly) parameter units is a line of
individual unit classifications. Each classification
must be less than 32 characters long. Embedded spaces
are permitted if the classification is enclosed in quotes.
This tag may be left out of the header if the value is zero.
</pre><p>
Table I lists generic tags for including information common to
all instrument types. Table II lists additional fields commonly
used with image data. Table III gives tags for ordered pair (XY)
type data, and Table IV adds tags for active sources. Several tags
are mandatory, depending upon type of data in the file. Tags
should be selected which provide the User with sufficient
information to read, understand, and evaluate the data file.<p>
<b>File Names</b><p>
Data archived at the AMSC will generally have the
the ".saf" extension for image files and ".pod" extension for Parameter
Oriented Data (POD) files.<p>
<b>Image Files</b><p>
All image files are preceded by the standard header as
described above. The header tag KeyWrd is used to identify the file
as one of three types:<p>
<pre>
IMG -> the data consists of intensity values.
CMAP -> the data consists of a color map and indices into the color map.
PAV -> the data consists of ordered triplets: x, y, and value.
</pre>
<p>
<b>IMG Image Files</b><p>
Rectangular image arrays have IMG as the KeyWrd value.
Following the header is the two dimensional image
data, consisting of an array of XPixls columns by Ypixls rows,
stored in row major order (row one, followed by row two, followed
by row three, etc.). If the file contains more than one field, the
image is assumed to be interlaced. Following the image array is
possibly a footer containing background information for Col or Row
type background subtraction (Note 1). These data consist of an array of
single precision floating point numbers, and this array can be
present even if another background subtraction scheme is used (Note 2).
The number of elements in this background array is XPixls for Col
background subtraction and YPixls for Row background subtraction.
The data units are specified by StdUnt (Note 21) for standard units,
or by DaUnit for other values.<p>
<b>CMAP Image Files</b><p>
Color mapped image files have CMAP as the KeyWrd value.
Following the standard header are 768 bytes of the color map, with
256 bytes each for red, green, and blue, respectively. Following
the color map are the image data. The value of each pixel in the
image is a zero-referenced subscript to a color in the color map.<p>
<b>PAV Image Files</b><p>
Position and Value image files have PAV as the KeyWrd value.
The data consists of ordered triplets of position in x and y followed
by the amplitude. The image reader code will interpolate the data
to generate a rectangular array of the size given by the XPixls and
YPixls tags. The image boundary points may be specified by using the
BndXX tags to specify the clockwise sequence of boundary points. The
origin is at the upper left hand corner of the image, with x increasing
to the right and y increasing downward. If any boundary points are
specified, then there must be at least three of them, in which case
a triangular area would be generated.<p>
<b>XY Data Files</b><p>
Ordered pair data (Radiance vs wavelength, pressure vs time,
In-band radiance vs axial distance, etc.) are preceded by the
standard header. The two column ordered array is then listed in an
xy format. One or more blank spaces separate the values in each
row. Parameter names are specified by XParam and YParam. Data
units for x and y are specified by XDaUnt and DaUnit.
<p>
An alternate form of an xy data file can be used (if desired)
when the x values are equally spaced in time, wavelength,
position, etc. For this form, only the y values are stored, with
the x values calculated using additional parameter tags (XYFRST,
XYLAST, NumDPs).<p>
<b>Active Source Files</b><p>
Active source tags are added to headers for images as appropriate
to describe both the active source and detector used in acquiring
data.<p>
<b>Parameter Oriented Data (POD) File Format</b><p>
An additional archive file format is defined for multiple
parameters to be stored in the same file, such as time history data.
Examples of such data are time, target position, velocity, and aspect
angle, or time, motor chamber pressure, turbine speed,
and case temperature, etc.<p>
The POD file format has a standard header, an optional line
of parameter names, an optional line of parameter units, an optional
line of parameter classifications, followed by the data. The data
may be arranged in columns (handy for human viewing), or in rows
(quicker computer access). Five tags are also required to define
the number of parameters in the file and the space
required for parameter names, units, and security classifications.
Additional information on the POD data file format is included
below.<p>
<pre>
A. Header Information - The header will consist of
standard SAF tags. The tag KeyWrd with value POD must be
included. The tag NParam will indicate the number of
parameters while the tag NumDPs will indicate the number
of data points (values) per parameter.
B. Parameter Names - A single line of text may be used
for the parameter names of the data. Spaces, tabs,
commas, colons, semicolons, and vertical bars may be used
as delimiters between parameter names. All parameters
will have names not exceeding 63 characters. Include the
PnSize tag with a positive value in the header to specify
the existence of the parameter names. Any parameter name
which includes a delimiter must be enclosed in quotes.
C. Parameter Units - A single line of text may be used
for the parameter units of the data. Spaces, tabs,
commas, colons, semicolons, and vertical bars may be used
as delimiters between parameter units. All parameters
will have units not exceeding 63 characters. Include the
PuSize tag with a positive value in the header to specify
the existence of the parameter units. Any parameter unit
which includes a delimiter must be enclosed in quotes.
Use a pair of double quotes ("") as a space holder for a
parameter which has no units.
D. Parameter Classification - A single line of text
may be used for the security classification of each
parameter. The Class tag in the header should reflect the
classification of the entire file. If this is the same
as for each parameter, only the Class tag need be used.
Otherwise, include a classification for each column and
include the PcSize tag with a positive value in the
header. The maximum length of a classification string is
31 characters. Any classification which includes a
delimiter must be enclosed in quotes.
E. Parameter Values - The remainder of the pod file
contains the parameter values. The data type of these
values is defined by the header tag DaType. All values
will have the same data type. If DaType is ASCII, then a
space, comma, tab, colon, semicolon, or vertical bar may
be used to separate parameter values. Non-numeric data
may only be stored in ASCII files. Quotes may be used to
group sequences of characters.
Example: HdSize Auto
Class Unclassified
DaType ASCII
Keywrd POD
PcSize 0
PuSize 1
PnSize 1
Nparam 6
NumDPs 5
Data
TIME ALTITUDE VELOCITY "ASPECT ANGLE" Filter Camera
sec. meters meters/sec degrees "" ""
0.0 0.0 0.0 90. 1 "NIKA 2"
1.0 10.0 1.0 89. 1 "NIKA 2"
2.0 20.0 2.0 88. 1 "NIKA 2"
3.0 30.0 3.0 87. 2 FTS
4.0 40.0 4.0 86. 2 FTS
</pre>
<b>Table I Generic Tags</b><p>
<pre>
Tag Description Type
HdSize Header Size (in bytes, or it may be AUTO) Integer
AqMode Acquisition Mode (<a href = "#note10">Note 10</a>) Text
AspAng Aspect Angle (degrees) Float
BgFile Background File (<a href="#note2">Notes 2</a>,<a href="#note6">6</a>) Text
BgType Background Type (<a href="#note1">Note 1</a>) Text
BgValu Background Value (Average or Fixed) (<a href="#note2">Note 2</a>) Float
BPFile Bad Pixel File (<a href="#note6">Note 6</a>) Text
BytOrd Byte Order (<a href="#note3">Note 3</a>) Text
CaFile Calibration File (<a href="#note2">Notes 2</a>,<a href="#note6">6</a>) Text
ChTemp High Temp of Cal Source (degrees C) Float
Class Classification Text
CIDay Collection IRIG Day Integer
CIHour Collection IRIG Hour Integer
CIMin Collection IRIG Minute Integer
CISec Collection IRIG Seconds Float
ClTemp Low Temp of Cal Source (degrees C) Float
COMENT Comment Line (Repeated as Required) Text
CSFile Calibration Source File (<a href="#note6">Note 6</a>) Text
Data End of header
DaType Data Type (<a href="#note4">Note 4</a>) Text
DaUnit Data Units (<a href="#note2">Note 2</a>) Text
DDOff Data Distribution Office Text
DiaFOV Circular FOV (degrees) Float
DiStat Distribution Statement Text
ElAng Elevation Angle (deg) Float
EURAW Processed Level of the Data EU/RAW/Flat-fielded (FF) Text
ExpID AMSC Experiment ID# Text
Filter Filter Name Text
Filtno Filter Number Integer
FOVAxl Chamber Test FOV Axial Location (meters) (<a href="#note7">Note 7</a>) Float
FOVRdl Chamber Test FOV Radial Location (meters) (<a href="#note8">Note 8</a>) Float
HdVers Header Version (= 2.0) Text
HorFOV Horizontal FOV (degrees) Float
IHFOV Instantaneous Horizontal FOV (microradians) Float
Itime Integration Time (seconds) Float
IVFOV Instantaneous Vertical FOV (microradians) Float
LinLog Linear/Log Indicator (LIN/LOG/ASG) (<a href="#note2">Notes 2</a>,<a href="#note5">5</a>,<a href="#note16">16</a>) Text
LODAng Observer Line-of-Sight Angle wrt True North (CW is +) Float
LogASl Log Amp Slope (<a href="#note5">Notes 5</a>,<a href="#note16">16</a>) Float
LogOff Log Offset (<a href="#note5">Notes 5</a>,<a href="#note16">16</a>) Float
Mach Mach Number Float
Mdate Mission Date (MM/DD/YY) Text
MeasUn Measurement Uncertainty-Nominal (%) Float
Miss Mission Text
NCoads Number of Coads Integer
NEQ Noise Equivalent Quantity (<a href="#note9">Note 9</a>) Float
NodeNo Node Number Text
Note01 Numbered Notes, valid from Note01 through Note99 Text
OffCor Offset Correction (<a href="#note2">Note 2</a>) Float
PPCNam Platform AMSC Component Name Text
RDFile Raw Data File (<a href="#note6">Note 6</a>) Text
RolAng Roll Angle (degrees) Float
SBPLo System Bandpass, Lower Wavelength (microns) Float
SBPUp System Bandpass, Upper Wavelength (microns) Float
SclFac Calibration or Scale Factor (<a href="#note2">Note 2</a>) Float
SDLevl SDIO Data Level (<a href="#note15">Note 15</a>) Text
SecCol Number of Seconds Collected Integer
SLFile Spectral Lamp File Text
SltRng Slant Range (meters) Float
SnsAlt Sensor Altitude (meters) Float
SPCNam Sensor AMSC Component Name Text
Stage Launch Vehicle Stage Number Float
StdUnt Standard Data Units Index (<a href="#note21">Note 21</a>) Integer
SUncLo Independent Parameter Uncertainty Lower Limit Float
SUncUp Independent Parameter Uncertainty Upper Limit Float
TALO TALO (seconds) Float
TAOA Target Angle of Attack (degrees) Float
Target Target Name Text
TestNo Test Number Text
TPCNam Target PC Component Name Text
TPFact Transmission Path Factor (<a href="#note2">Note 2</a>) Float
TrgAlt Target Altitude (meters) Float
TrgHdg Target Heading with respect to True North (CW is pos) Float
TrgTyp Target Type (Liquid/Solid) Text
TrgVel Target Velocity (meters/second) Float
TrlNum Trial Number Text
TZDay T-Zero Day Integer
TZHour T-Zero Hour Integer
TZMin T-Zero Minute Integer
TZSec T-Zero Seconds Float
USRCON User-Specified Parameters Header Filename (<a href="#note17">Note 17</a>) Text
VrtFOV Vertical FOV (degrees) Float
Warn01 Warning to the user, valid from 01 thru 99 Text
XUncUn Independent Parameter Uncertainty Units Float
YUncLo Dependent Parameter Uncertainty Lower Limit Float
YUncLo Dependent Parameter Uncertainty Upper Limit Float
YUncUn Dependent Parameter Uncertainty Units Float
</pre>
<b>Table II Imager Tags</b><p>
<pre>
Tag Description Type
ACFile Area Correction Factor File Text
ADJFAC Non-Linear Adjustment Factor Float
ApSize Aperture Size Float
BGBLLX Lower Left X for Background Box (<a href="#note2">Note 2</a>) Integer
BGBLLY Lower Left Y for Background Box (<a href="#note2">Note 2</a>) Integer
BGBLRX Lower Right X for Background Box (<a href="#note2">Note 2</a>) Integer
BGBLRY Lower Right Y for Background Box (<a href="#note2">Note 2</a>) Integer
BGBULX Upper Left X for Background Box (<a href="#note2">Note 2</a>) Integer
BGBULY Upper Left Y for Background Box (<a href="#note2">Note 2</a>) Integer
BGBURX Upper Right X for Background Box (<a href="#note2">Note 2</a>) Integer
BGBURY Upper Right Y for Background Box (<a href="#note2">Note 2</a>) Integer
Bnd01 Boundary Point for PAV files, valid from 01 thru 99 Integer
Bx1Int Box 1 Integral Value Float
Bx1LLX Box 1 Lower Left X Integer
Bx1LLY Box 1 Lower Left Y Integer
Bx1LRX Box 1 Lower Right X Integer
Bx1LRY Box 1 Lower Right Y Integer
Bx1ULX Box 1 Upper Left X Integer
Bx1ULY Box 1 Upper Left Y Integer
Bx1URX Box 1 Upper Right X Integer
Bx1URY Box 1 Upper Right Y Integer
Bx2Int Box 2 Integral Value Float
Bx2LLY Box 2 Lower Left X Integer
Bx2LLY Box 2 Lower Left Y Integer
Bx2LRX Box 2 Lower Right X Integer
Bx2ULX Box 2 Upper Left X Integer
Bx2ULY Box 2 Upper Left Y Integer
Bx2URX Box 2 Upper Right X Integer
Bx2URY Box 2 Upper Right Y Integer
CentMX Center Cursor X Position Integer
CentMY Center Cursor Y Position Integer
CGain Camera Gain Float
Colr1 Color 1 Value Text
Colr2 Color 2 Value Text
Colr3 Color 3 Value Text
Colr4 Color 4 Value Text
Colr5 Color 5 Value Text
Colr6 Color 6 Value Text
Colr7 Color 7 Value Text
Colr8 Color 8 Value Text
Colr9 Color 9 Value Text
Colr10 Color 10 Value Text
Colr11 Color 11 Value Text
Colr12 Color 12 Value Text
Colr13 Color 13 Value Text
Colr14 Color 14 Value Text
Colr15 Color 15 Value Text
Colr16 Color 16 Value Text
ComPrs Compression Type (<a href = "#note25">Note 25</a>) Text
DGFld Digitizer Gamma setting (non-linear adj.) (<a href="#note14">Note 14</a>) Float
DiType Digitizer Type (<a href="#note14">Note 14</a>) Text
DPtNum Data Point Number Integer
DSGain Digitizer System Gain Float
DSOff Digitizer System Offset Float
FldFrm Fields per Frame Integer
FlorFr Field or Frame Data in this File Text
FRate Frame Rate (frames/second) Float
FrstCl First Color Integer
EMFile Emissivity File Text
IDFile Image Display Control File (<a href="#note6">Note 6</a>) Text
ImDisp Pre-digitized image display format (<a href="#note14">Note 14</a>) Text
ImQual Image Quality (<a href="#note11">Note 11</a>) Text
ImSig Pre-digitized image signal type (<a href="#note14">Note 14</a>) Text
ImSize Image Size (in bytes after any compression) Integer
Intrlc Frame Data Are Interlaced in the File Text
NClrs Number of Colors Used Integer
PLeftX Profile Left X Integer
PLeftY Profile Left Y Integer
PRghtX Profile Right X Integer
PRghtY Profile Right Y Integer
ProCX Profile Cursor X Integer
ProCY Profile Cursor Y Integer
SpecFn Special Function to apply to the image (<a href = "#note23">Note 23</a>) Text
SRFile Slant Range Correction Factor File Text
VrtAtt Vertical Attitude (degrees) Float
XMag X Compress or Enlarge Factor Float
XPixls Digitized Data Image Width (pixels) Integer
XPxWid X (horizontal) Pixel Width (meters) Float
YMag Y Compress or Enlarge Factor Float
YMax Maximum y value Float
YMin Minimum value Float
YPixls Digitized Data Image Height (pixels) Integer
YPxWid Y (vertical) Pixel Width (meters) Float
</pre>
<b>Table III Data Tags</b><p>
<pre>
Tag Description Type
Calc01 Calculated Parameter, valid from 01 thru 99 (<a href = "#note24">Note 24</a>) Text
FreRsp System Electrical Frequency Response (Hz) Float
Keywrd XY File Keyword (<a href="#note12">Note 12</a>) Text
NParam Number of Parameters in File Integer
NumDPs Number of Data Points in File Integer
PcSize Parameter Classification Size (bytes) Integer
PltSub XY Plot Subtitle Text
PltTtl XY Plot Title Text
PnSize Parameter Name Size (bytes) Integer
PodOrd Data Ordering in POD Files (<a href="#note20">Note 20</a>) Text
PuSize Parameter Units Size (bytes) Integer
SampRa Sample Rate (Hz) Float
XCFile X-Axis Calibration File Text
XDaUnt X-Axis Data Units Text
XFName X-Axis File Name (a 1 parameter POD file) Text
XParam X-Axis Parameter name Text
XScFac X-Axis Scale Factor (applied to XFName values) Float
XYFNum XY File Number Integer
XYFrst XY First Value Float
XYLast XY Last Value Float
YParam Y-Axis Parameter name Text
</pre>
<b>Table IV Active Source Tags</b><p>
<pre>
Tag Description Type
SrcNam Active Source AMSC Component Name Text
SrcWav Active Source Wavelength or Frequency (<a href="#note13">Note 13</a>) Float
SrcWid Active Source Scan Width (GHz) Float
SrcWUn Source Wavelength or Frequency Units (<a href="#note13">Note 13</a>) Text
SrcRat Active Source Scan Rate (Hz) Float
</pre>
<p><b>NOTES</b><p>
<a name="note1"><b>1. Background Type Code (BgType)</b><p></a>
<pre>
Col Column Average (each column has an average background
value)
Row Row Average (each row has an average background value)
Avg Floating Box Average
File File Subtraction
Fix Fixed Value
None Assume Zero Background
</pre>
<a name="note2"><b>2. Linear Data EUD Calculation</b><p></a>
This information was originally provided for image data sets,
but can be adapted as required for other data set types.
Instrument specific variations in this equation should be
documented with the data set in an ASCII file.<p>
The linear data mode is indicated by LIN in the LinLog field. The
equation for converting the pixel values to engineering units is<p>
<pre>
EUD = (PixelValue - Background)*SclFac*TPFact+OffCor
</pre>
The units of the resulting value are defined in DaUnit. The
individual pixel values and the background value(s) are required to
have the same units (i.e., counts of volts). SclFac is
responsivity factor for the instrument which obtained the data,
and is defined in radiance per detector output units (i.e., W/sr-
cm<sup>2</sup>-count or W/sr-cm<sup>2</sup>-volt).
Scale Factors (SclFac) which vary on
a pixel by pixel basis are stored in the file identified in Cafile.
If neither CaFile or SclFac are specified, SclFac defaults to 1.0
for all pixels.<p>
TPFact is a dimensionless correction factor to adjust for
transmission path effects, and defaults to 1.0 if not present.
OffCor is an optional data correction offset factor (with a default
of 0.0) and has the units defined in DaUnit. If the background
type (BgType) is set to None or not present, the background
defaults to 0.<p>
For Avg and Fix backgrounds, the background value, which is
the same for all pixels, is defined in BgValu. In addition, for
the Avg type of background, the corners of the box used to compute
the background are given in (BGBULX, BGBULY), (BGBURX, BGBURY),
(BGBLLX, BGBLLY), and (BGBLRX, BGBLRY).<p>
If the background type is Row, the footer contains an array of
floating point number of dimension Ypixls. Then for all pixels in
row 1 of the image, the first element of the footer array is used
as the background; for all pixels in row 2 of the image, the second
element of the footer array is used as the background, etc.<p>
If the background type is Col, the footer contains an array of
floating point number of dimension XPixls. Then, for all pixels in
column 1 of the image, the first element of the footer array is
used as the background; for all pixels in volume 2 of the image,
the second element of the footer array is used as the background,
etc.<p>
If the background type is File, the BgFile field must contain
a name for a background image file of the same format as all
standard images. For file background subtraction, the background
value for any pixel in the image file is the corresponding pixel in
the background image.<p>
<a name="note3"><b>3. Byte Order Codes (BytOrd)</b><p></a>
<pre>
LH Low order byte first (Typical DOS application)
HL High order byte first
VX VAX byte order
</pre>
<a name="note4"><b>4. Data Type Codes (DaType)</b><p></a>
<pre>
ASCII ASCII
Int8 1-byte integer (0-255 unsigned)
Int16 2-byte integer
Int32 4-byte integer
Int64 8-byte integer
Flt32 Single precision floating point
Flt64 Double precision floating point
RGB24 24-bit color image (3 bytes per pixel, RGB)
</pre>
<a name="note5"><b>5. Log Data EUD Calculation (LogASl, LogOff)</b><p></a>
This information was originally provided for image data sets,
but can be adapted as required for other data set types.
Instrument specific variations in this equation should be
documented with the data set in an ASCII file.<p>
This mode of operation is indicated by the presence of LOG in
the LinLog field. The equation for converting log camera data to
engineering units is<p>
<pre>
EUD = SclFac*TPFact)*(10^(LogASl*(PixelValue-LogOff)) - 10^(LogASl*(Background-LogOff)))
</pre>
where SclFac, TPFact, OffCor, and DaUnit are defined the same as
for linear data and LogOff is a tape recorder offset adjustment
which defaults to 0. If the background type is set to None or not
present, the second term in the equation (enclosed in braces [])
defaults to 0.<p>
<a name="note6"><b>6. Ancillary Files</b><p></a>
Any files named in the standard header are themselves required
to have a standard header.<p>
<a name="note7"><b>7. Captive test FOV Axial Location (FOVAxl)</b><p></a>
This parameter is defined as the distance from the nozzle exit
to the center of the FOV (center pixel in the digitized image)
parallel to the direction of flow and normal to the nozzle exit
plane, with positive values in the direction of flow. The axial
location is typically specified only for near-field test chamber or
static test measurements.<p>
For target aspect angles of 0 deg (nose-on) or 180 deg (tail-
on), this parameter represents the horizontal distance to the
target center.<p>
<a name="note8"><b>8. Captive Test FOV Radial Location (FOVRdl)</b><p></a>
This parameter is defined as the distance from the plume
centerline to the center of the FOV (center pixel in the digitized
image) in a line normal to the direction of flow and parallel with
the nozzle exit plane, with positive values being up and to the
right in the digitized image. The radial location is typically
specified only for near-field test chamber or static test
measurements. For target aspect angles of 0 deg (nose-on) or 180
deg (tail-on), this parameter represents the horizontal distance to
the target center.<p>
<a name="note9"><b>9. Noise Equivalent Quantity (NEQ)</b><p></a>
This parameter has the units defined in DaUnits. The intent
is to identify the rms noise level in the data. Nominal values
should be specified and separate files archived as required for
spatially or temporally dependent noise equivalent parameters.<p>
<a name="note10"><b>10. Acquisition Mode Codes (AqMode)</b><p></a>
<pre>
FM FM Tape
LV Live (Real time digitization)
OP Video Optical Disk
UM Umatic Tape
VR VCR
SV Super VHS
D2 D2 Digital Video Tape
</pre>
<a name="note11"><b>11. Quality Codes (ImQual)</b><p></a>
<pre>
OK Preferred Image, scan or data point
NO Non-preferred Image, scan or data point
</pre>
<a name="note12"><b>12. SAF Keyword Codes (KeyWrd)</b><p></a>
<pre>
Data Format KeyWrd Description
Image IMG 2-D array of values (This is the
default tag value)
CMAP 2-D array of color map indices
PAV Position and value triplets
Parameter Oriented Data POD Multiple dependent parameters with
the same independent parameter
xy pairs XYPT (x,y) pairs, y vs. points
XYFN (x,y) pairs, y vs. file number
XYTM (x,y) pairs, vs. time
XYDI (x,y) pairs, y vs. distance (in meters)
y values only YPT y vs. points
YFN y vs. file number
YTM y vs. time
YDI y vs. distance (in meters)
YWL y vs. wavelength
YWN y vs. wavenumber
</pre>
<a name="note13"><b>13. Active Source Wavelength and Units (SrcWav, SrcWUn)</b><p></a>
Not a required parameter for lamps or blackbodies. Standard
units are micron, GHz or cm<sup>-1</sup>.<p>
<a name="note14"><b>14. Digitizer Settings</b></a>
<p> Digitizer system settings are required to maintain traceability
and repeatability. Pre-digitized image information to be listed
includes the display type and the signal type. The Gamma setting
is required for Quantex-digitized imagery. Options are listed in
the table below.<p>
<pre>
PARAMETER DIGITIZER IMAGE DISPLAY
TYPE SIGNAL TYPE
Tag DiType ImSig ImDisp
Possible Quantex RGB Color
Values Matrox NTSC
RCI_RTD_8* PAL
RCI_RTD_10* SECAM
YUV_RTD_8**
*RCI Real-Time Disk, 8-bit or 10-bit Resolution
**RCI YUV File Format, 8-bit Resolution
</pre>
<a name="note15"><b>15. SDIO Data Levels (SDLevl)</b><p></a>
<pre>
Level Description
0 Telemetry data as received by ground stations. Both digital
and analog.
1 Data processed by ground station into digitized,
decommutated data, in proper time order, separated by
sensor, time-tagged, with collateral data attached. Data is
placed into a raw database.
2 Data reduced to scientific and engineering units by
application of calibration data. Time-tag converted to GMT.
Data is assembled into a reduced database.
3 Fully characterized, validated level 2 data.
Characterization includes target characteristics, range,
fuel type, etc, atmospheric conditions; as well as a
complete sensor characterization.
</pre>
<a name="note16"><b>16. ASG IRIS DATA EUD CALCULATION (from Flat-Fielded Data)</b></a><p>
<pre>
EU = Exp[{ln(x-bg)-a} / b]
a = LogASl in header
b = LogOff in header
bg = Background Value
x = Pixel Value
</pre>
<a name="note17"><b>17. User Controlled Tags (USRCON)</b></a><p>
Certain experiments may have specific and exceptional
information to be included in the header. For such programs, a
second header file is created in the same format as the standard
file which includes tags and associated information. This file is
named as specified by the parameter USRCON in the standard header.
It is the responsibility of the archivist to provide sufficient
documentation describing the user-specified tags and definitions.<p>
<a name="note18"><b>18. Stage Number (Stage)</b></a><p>
This tag is used to indicate which stage is thrusting during
powered flight. For most data sets and targets, the use of this
tag will be straight forward. Nomenclature or conventions are not
specified by this document for instances when the target coasts
between stages, there are combination burns of different stages
(e.g. Titan 34D), or when prominent interstage events occur. This
tag is used by some AMSC Software tools to graphically indicate the
approximate operating times or regions for the various stages.<p>
<a name="note19"><b>19. Target Type Definitions (TRGTYP)</b></a><p>
<pre>
Liquid Liquid Rocket Engine
Solid Solid Rocket Motor
Liquid/Solid Dual System using a combination of both types
of propulsion systems
</pre>
<a name="note20"><b>20. Data Ordering in POD Files (PodOrd)</b></a><p>
This tag is used to indicate the storage order in POD files.
The default value is COL, which is most suitable for ASCII
files. In this case the data for each parameter is in a column,
with each row having one value for each parameter. For binary
files, the alternate value Row is more suitable. In this case all
the data for each parameter occupies one row in the file. For
binary files this means that all the data for each parameter is
contiguous, allowing faster access.<p>
<a name="note21"><b>21. Standard Data Units (StdUnt)</b></a><p>
Standard data units are specified using this tag. For human readability
of the header information, the data units may be placed in the header
using the DaUnit tag also. The StdUnt tag will take precedence over
the DaUnit tag.<p>
<pre>
Index Units Standard Abbreviation
0 Nonstandard, use DaUnit
1 Counts cnt
2 Volts V
3 Amperes A
4 Watts W
5 Fahrenheit Temperature deg F
6 Celsius Temperature deg C
7 Rankine Temperature deg R
8 Kelvin Temperature K
9 Meters m
10 Centimeters cm
11 Kilometers km
12 Micrometers um
13 Seconds sec
14 Steradians sr
15 In-Band Radiant Intensity W/sr
16 In-Band Irradiance W/cm^2
17 In-Band Radiance W/(sr cm^2)
18 Spectral Radiant Intensity W/(sr um)
19 Spectral Irradiance W/(cm^2 um)
20 Spectral Radiance W/(sr cm^2 um)
21 Station Radiance W/(sr cm)
</pre>
<a name="note22"><b>22. AMSC Default SAF Parameters</b><p></a>
Default values for common header parameters utilized by various AMSC
analysis tools are listed below. These are supplied by the
software if parameters are not included in the SAF file.<p>
<pre>
TAG VALUE
BgType NONE
BgValu 0.0
Class Unclassified
EURaw RAW
FldFrm 2
FlorFr FRAME
Frate 30
Intrlc NO
Keywrd IMG
LinLog LIN
OffCor 0.0
PodOrd Column
SclFac 1.0
TPFact 1.0
ComPrs None
</pre>
<a name="note23"><b>23. Special Function Applied to Images</b></a><p>
The text value of the SpecFn tag is an algebraic expression which is to be applied to
the image after all other processing is completed. Header values are referenced
as $tag where 'tag' is the name of the desired header tag.
Each pixel value is referenced as x. Thus a sample expression is<p>
<pre>"1.01 + x + sin(x*pi) / ($TALO/2)^3".</pre><p>
<a name="note24"><b>24. Calculated Parameters</b></a><p>
The analysis software will parse the text value of each CalcXX tag for the name, units,
and the algebraic expression which defines this parameter. The parameter values
will be calculated. Header values may be referenced by $tag where 'tag' is the
name of the desired header value. The value of other parameters included in the
file are referenced by placing the case sensitive name in single quotes. There
may be up to 99 such parameters.<p>
A sample text value is<p>
<pre>"Mach Number", "", "'speed' * 1024.2 / $Temp^2"</pre>
<a name="note25"><b>25. Compression Type</b></a><p>
To save space, image data may be compressed. The only compression presently
supported is gzip. The possible values are None and GZIP.
