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svnav.dat

A table of the physical characteristics of the GPS satellites

Overview

The svnav.dat file effectively contains a description of the physical characteristics of the GPS satellites. Ignoring the two descriptive, header lines which begin this file, each line contains:

1. the PRN number
2. the corresponding Navstar number
3. a number representing the satellite's Block
   In this case, a satellite block number is analogous to a version or model number. For example, because of the asymmetrical placement of venting/radiation panels, the Block I satellites behave very differently from later generations. The Block number is, in essence, a code for the design of the satellite.
4. the mass of the satellite (in grams)
5. a yaw bias flag
6. a yaw rate
   When in eclipse, a GPS satellite will start yawing (rotating) in an attempt to recover the Sun and orient themselves. This, in turn, changes the expected location of the satellite's antenna creating an additional, varying, transient offset, and causes additional forces upon the satellite because of it's "peculiar" orientation towards the Sun. This yawing can be modelled given the rate the rate and direction of the rotation.
7. the launch date

Example

  NSN/PRN #s, masses, and yaw rates satellites.   Updated by R. King 20 September 96
PRN NS BLK  MASS(G)  BIASED  YAW RATE  YR MO DY HR MN  (Biased Y: normal, A: anti-normal, P: +ive only, N: -ive only, U: unbiased )
 4,  1  1  453800.0     U     0.1990   78 02 22 00 00
 7,  2  1  453800.0     U     0.1990   78 05 13 00 00
 6,  3  1  453800.0     U     0.1990   78 10 06 00 00
 8,  4  1  440900.0     U     0.1990   78 12 10 00 00
 5,  5  1  462600.0     U     0.1990   80 02 09 00 00
 9,  6  1  462600.0     U     0.1990   80 04 26 00 00
11,  8  1  522200.0     U     0.1990   83 08 10 00 00
13,  9  1  520400.0     U     0.1990   84 07 19 00 00
13,  9  1  520400.0     Y     0.1990   94 06 06 00 00
12, 10  1  519800.0     U     0.1990   84 10 03 00 00
 3, 11  1  521800.0     U     0.1990   85 10 30 00 00
 3, 11  1  521800.0     Y     0.1990   94 06 06 00 00
 2, 13  2  878200.0     U     0.1130   89 08 10 00 00
 2, 13  2  878200.0     Y     0.1130   93 01 01 00 00
 2, 13  2  878200.0     N     0.1130   95 07 05 01 10
 2, 13  2  878200.0     P     0.1130   95 11 17 00 00
14, 14  2  887400.0     U     0.0870   89 04 15 00 00
14, 14  2  887400.0     Y     0.0870   95 01 31 23 00
14, 14  2  887400.0     U     0.0870   95 02 08 02 00

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