PDS_VERSION_ID      = PDS3                                                    
RECORD_TYPE         = FIXED_LENGTH                                            
RECORD_BYTES        = 80                                                      
OBJECT              = TEXT                                                    
  PUBLICATION_DATE    = 1985-06-01                                            
  NOTE                = "DSN Media Calibration Data File Software             
                         Interface Specification.  Typed in from hard         
                         copy original "                                      
END_OBJECT          = TEXT                                                    
END                                                                           
                                                                              
                        DOCUMENT 820-13; REV. A                               
                        DSN SYSTEM REQUIREMENTS                               
                       DETAILED INTERFACE DESIGN                              
                                                                              
                               TRK-2-23                                       
                     DSN Tracking System Interfaces                           
                    Media Calibration Data Interface                          
                                                                              
(Insert this module in Document 820-13; Rev. A)                               
                                                                              
EFFECTIVE DATE:  Mark IVA Implementation                                      
---------------------------------------------------------------------         
Initial Release Date: June 1, 1985                                            
                                                                              
                            Approved by: s/Joseph A. Wackley  (430)           
                                         --------------------------           
                                                                              
                                         s/Herbert N. Royden  (335)           
                                         --------------------------           
                                                                              
                                         s/Gene L. Goltz      (314)           
                                         --------------------------           
                                                                              
A. PURPOSE                                                                    
                                                                              
      This module defines the formats and content of the media calibration    
data provided by the Tracking System Analytic Calibration (TSAC) group.       
                                                                              
B. REVISION AND CONTROL                                                       
                                                                              
      Revisions or changes to the information herein presented may be         
initiated in accordance with the procedures in Section I of this document.    
                                                                              
C. GENERAL INFORMATION                                                        
                                                                              
      Media calibrations provided by the DSN are used by project navigation   
teams to improve the accuracy of spacecraft orbit determination; they are     
also used by project Radio Science teams and other investigators.  The        
calibrations comprise corrections for the effects of transmission media       
(troposphere, ionosphere, and solar plasma) on the radio metric data.  The    
media calibrations are to be provided at intervals determined by the accuracy 
and timeliness requirements of the primary users and by negotiations with the 
various DSN users.                                                            
                                                                              
D. DATA FORMATS                                                               
                                                                              
      1. General Description                                                  
                                                                              
            All TSAC calibrations are provided in the form of card images (or 
punched cards, if necessary) in files on the JPL user's computer.  On the     
Univac 1100/81 computers, the files are in field data format (SDF); on all    
other computers, they are in American Standard Code for Information           
Interchange (ASCII) format.                                                   
                                                                              
            TSAC media calibrations conform to the Command Statement          
Processor (CSP) English-like command language used by the Orbit Determination 
Program (ODP) to adjust, delete, or weight data points.  The language is      
described in detail in the DPTRAJ-ODP User's Reference Manual (618-783 Rev.   
B, Vol. 1, Section 36).                                                       
                                                                              
            In  general, a CSP command consists of a verb and optional scope  
limiters and computation specifiers, terminated by a period.  A command may,  
and frequently does, extend over more than one card image.  The CSP commands  
produced by the TSAC software comprise a small subset of those used by the    
ODP.  Elements of CSP commands used in the TSAC media calibrations are given  
in Table TRK-2-23-2; examples of the calibrations are given below under the   
sub-headings Tropospheric Calibrations, Ionospheric Calibrations, and Solar   
Plasma Calibrations.                                                          
                                                                              
                                                                              
   Table TRK-2-23-1.  CSP Elements Used in TSAC Media Calibrations            
|===================================================================|         
|      Type of Element      |  Elements Used                        |         
|===========================|=======================================|         
| Verbs                     | ADJUST, DELETE                        |         
|---------------------------+---------------------------------------|         
| Scope Limiters            | Time Span Limiters:                   |         
|                           | FROM                BEFORE            |         
|                           | TO                  AFTER             |         
|                           | AT                                    |         
|                           |                                       |         
|                           | Network (Complex or Station):         |         
|                           | DSN                                   |         
|                           | C10                 11, 12, 13, 14    |         
|                           | C40                 42, 43, 44        |         
|                           | C60                 61, 62, 63        |         
|                           |                                       |         
|                           | Band:  S, X; L (VAX ODP only)         |         
|                           |                                       |         
|                           | Source:  SCID, QUASAR                 |         
|                           |                                       |         
|---------------------------+---------------------------------------|         
| Computation Specifiers    | Series Type:                          |         
|                           | BY NRMPOW            BY DNRMPOW       |         
|                           | BY CONST             BY DCONST        |         
|                           | BY TRIG              BY DTRIG         |         
|                           |                                       |         
|                           | Model:                                |         
|                           | DRY NUPART (dry troposphere)          |         
|                           | WET NUPART (tropospheric water vapor) |         
|                           | CHPART (ionosphere)                   |         
|                           | DRVID (ionosphere + solar plasma)     |         
|                           |                                       |         
|                           | Data Type:                            |         
|                           | DOPPLER            F1, F2, F3, F3C    |         
|                           | RANGE              PLOP               |         
|                           | VLBI                                  |         
|                           | DVLBI                                 |         
|                           |                                       |         
|===========================|=======================================|         
                                                                              
      2. Time Formats                                                         
                                                                              
            Times are preceded by a time-span limiter (FROM, TO, AT,          
BEFORE, or AFTER) and are enclosed in parentheses.  The format is             
(YY/MM/DD,HH:MM:SS).  The year, month, day, hour, and minute values are       
integers; seconds are double precision.  Up to three of the right-most time   
fields may be omitted.  When omitted, their values are taken to be zeroes.    
The calibrations apply only during the times specified by the time-span       
limiter(s).  If the limiter is AT, the time span depends on the computer      
word length.  On the UNIVAC (36-bit word length), the time span is from one   
microsecond before the given time to one microsecond after; on the VAX        
(32-bit word length), it is from one millisecond before to one millisecond    
after.                                                                        
                                                                              
      3. Number Formats                                                       
                                                                              
      The formats for integers and single- and double-precision floating-     
point numbers are the same as in FORTRAN.  In addition, the sign of the       
exponent of a floating point number may replace the letter D or E; for        
example, 1.234E-3 may be written 1.234-3.                                     
                                                                              
      4. Comments                                                             
                                                                              
      Additional explanatory information, not to be used by the ODP, may      
appear on a command provided that it is preceded by the number sign (#).      
Characters following the number sign are ignored by the ODP.                  
                                                                              
      5. Series Type                                                          
                                                                              
      Media calibrations may be specified by a normalized power series        
(NRMPOW), a single constant (CONST), or a Fourier series (TRIG).  If the      
coefficients or constant are double precision, the computation specifier is   
preceded by the letter "D" (e.g., DNRMPOW).                                   
                                                                              
      If the ADJUST command contained BY NRMPOW (C0, C1,  ..., CN) FROM (S)   
TO (E), where S and E refer to the start and end times for the command, the   
calibration is computed from the normalized power series C0 + C1 * X + C2 *   
X^2 + ... + CN * X^N.  This polynomial is called "normalized" because the     
time argument of the series, T, has been replaced by the normalized,          
dimensionless argument X, which is defined to be -1 when T = S and +1 when T  
= E.  This normalization is done by a change of variable given by             
                                                                              
                     X = 2*( (T-S)/(E-S) ) -1.                                
                                                                              
Up to 24 single-precision or 12 double-precision coefficients are allowed in  
one series.                                                                   
                                                                              
      If the ADJUST command contains BY CONST (C), the calibration is given   
by the constant C.                                                            
                                                                              
      If the ADJUST command contains BY TRIG (P, A0, A1, B1, A2, B2, ..., AN, 
BN) AFTER (S), the calibration is given by the Fourier series                 
                                                                              
      A0 + A1 cos x + B1 sin x + A2 cos 2x + B2 sin 2x + ...                  
                               + AN cos Nx + BN sin Nx,                       
                                                                              
where x = 2 * PI * (T-S)/P; P is the period of the fundamental mode, in       
seconds.                                                                      
                                                                              
      6. Sign of Calibration                                                  
                                                                              
      In the ODP, the calibration is, effectively, always subtracted from     
the observable.  Range calibrations, then, will always be positive; a         
positive sign corresponds to a range delay.                                   
                                                                              
      7. Tropospheric Calibrations                                            
                                                                              
      Tropospheric calibrations are currently given by a normalized power     
series representing the seasonal variation over a two-year span.   Two        
series are given for each station or complex; the "dry" and "wet" components  
of one-way zenith range delay in meters.  The dry component, typically about  
2 meters, is the delay due to the nonwater-vapor components of the atmosphere 
(N2, O2, CO2, and Ar), whose proportions are essentially constant.  The wet   
component, typically a few centimeters, is the contribution of the highly     
variable water-vapor content of the atmosphere.  The program using the        
tropospheric calibrations must determine the line-of-sight delay by mapping   
each zenith component to the elevation angle corresponding to the line-of-    
sight;  the ODP performs this function by using separate dry and wet mapping  
tables.                                                                       
                                                                              
      An example of the format for tropospheric calibrations is given in      
Figure TRK-2-23-1 of this module.                                             
                                                                              
|===========================================================================| 
|ADJUST (ALL) BY NRMPOW (.5385215940876400-001,-.1545263252791661+000,      | 
| .6120410421392178+000,.8393903860788785+000,-.1757061589993537+001,       | 
| -.1192449606993796+001,.1774783212089319+001,.6265889342013949+000,       | 
| -.7481685636314813+000,-.1116904190364361+000,.1136781820255777+000) MODEL| 
| (WET NUPART) FROM (83/1/1,00:00:00.01) TO (85/1/1) DSN (C10).             | 
|===========================================================================| 
          Figure TRK-2-23-1.  Format for Tropospheric Calibrations            
                                                                              
      8. Ionospheric Calibrations                                             
                                                                              
      Ionospheric calibrations are given by a normalized power series for     
each spacecraft pass at each DSN complex.  The calibration represents the     
one-way line-of-sight ionospheric range delay in meters at S-band (2295 MHz). 
>From this polynomial, the ODP calculates Doppler corrections (in Hz) and     
range corrections (in range units) for each data point in its OD file.        
                                                                              
      The magnitude of the vertical ionospheric range delay at each complex   
depends on time of day, season, and time since start of the current solar     
cycle; it can range from less than 1 meter to more than 8 meters.  Because    
the slant-range adjustment factor can vary from unity at zenith to about 3.5  
at 0 degrees elevation, the resulting total variation in line-of-sight        
ionospheric calibration can range from less than 1 meter to more than 25      
meters.                                                                       
                                                                              
      The time spans of each polynomial, except in special circumstances, are 
from spacecraft rise (0 deg) to spacecraft set (0 deg) at the station or      
complex.                                                                      
                                                                              
      An example of the format for ionospheric calibrations is given in       
Figure TRK-2-23-2.                                                            
                                                                              
|===========================================================================| 
|ADJUST (ALL) BY NRMPOW (.127504448000000D+001,-.363046489000000D+000,      | 
| .221433675000000D+001,.385002747000000D+000,-.476505244000000D-001,       | 
| -.379998393000000D+000) MODEL (CHPART) FROM (84/10/31.20:40:55) TO        | 
| (84/11/1,10:45:30) DSN (C40). #S/C32 PRED S66 841011                      | 
|===========================================================================| 
         Figure TRK-2-23-2.  Format for Ionospheric Calibrations              
                                                                              
      9. Solar Plasma Calibrations                                            
                                                                              
      Solar plasma calibrations are given by a single constant that applies   
only at the time tag of an individual data point.  Units are the same as      
those of the observables; for example, range units for range and Hertz for    
Doppler.  The TSAC software reads the ODP input data file to get the time     
tags, and also removes the ionospheric portion of the downlink S/Z dual-      
frequency Doppler measurements so that only the solar plasma contributions    
remain.                                                                       
                                                                              
      An example of the format for solar plasma calibrations is given in      
Figure TRK-2-23-3.                                                            
                                                                              
|===========================================================================| 
|ADJUST (F2) BY CONST (.38755-001) AT (84/10/1.00:03:30) DSN (43) BAND (S). | 
|ADJUST(PLOP) BY CONST (.69398+002) AT (84/10/1.00:19:46) DSN (43) BAND (S).| 
|ADJUST (F2) BY CONST (.36505-001) AT (84/10/1.00:20:30) DSN (43) BAND (S). | 
|ADJUST (F2) BY CONST (.20189-001) AT (84/10/1.00:36:30) DSN (43) BAND (S). | 
|ADJUST(PLOP) BY CONST (.54675+002) AT (84/10/1.00:38:03) DSN (43) BAND (S).| 
|ADJUST (F2) BY CONST (-.58993-001) AT (84/10/1.00:47:30) DSN (43) BAND (S).| 
|ADJUST (F2) BY CONST (-.50877-001) AT (84/10/1.00:54:30) DSN (43) BAND (S).| 
|ADJUST(PLOP) BY CONST (.69124+002) AT (84/10/1.00:56:20) DSN (43) BAND (S).| 
|ADJUST (F2) BY CONST (-.70260-001) AT (84/10/1.01:01:30) DSN (43) BAND (S).| 
|===========================================================================| 
         Figure TRK-2-23-3.  Format for Solar Plasma Calibrations             
NB: First number in parentheses has been truncated from 10 mantissa digits    
to 5 mantissa digits to permit display within 80 character line limit here.   
                                                                              
