checkorb [ parameter=value ]
Parameters are: inputfile, dist_diff, date_diff, int_check, ext_check, header, satellite .
checkorb reads records with 1-line orbital elements from the ASCII formatted file and validates them by comparing them to each other (internal validation) as well as with the entries from the TeraScan ephemeris database. Comparison of two sets of orbital elements consists of computing the satellite motion for each set for a 24-hour period of time and then comparing the results. The entries in the input file must have the same satellite code and also be sorted by date in ascending order. Internal comparison is performed for all sequential pairs of input records, provided their dates are not too far apart from each other. External comparison uses the database entries with the closest dates.
checkorb can be useful for validating the new orbital elements intended for the ephemeris database update as well as for validating already existing ephemeris.
The name of the ASCII formatted file of orbital elements. To validate the ephemeris database the name $SATDATA/<satel>/orbinput has to be used.
There is no default.
The maximum difference in kilometers in the predicted satellite position that needs to be reported.
The default is 5 kilometers.
The maximum difference in days between the dates of the compared orbital elements when this comparison still should be done.
The default is the value of ORBDATEDIFF environment variable. If it is not defined, the value is 15 days.
Whether internal checking is needed.
The valid answers are yes or no. The default answer is yes.
Whether external checking is needed.
The valid answers are yes or no. The default answer is yes.
whether the first input record is a header identical to those in $SATDATA/<satellite>/orbinput files.
The valid answers are yes or no. The default answer is no.
Prompted only if header=no. The satellite name. This name is important only if an external comparison is to be done.
The valid answer is any valid satellite name. There is no default.
% checkorb inputfile : char(255) ? /refdata/satel/noaa-12/orbinput dist_diff : real ? [5] date_diff : int ? [15] int_check : char( 3) ? [yes] ext_check : char( 3) ? [yes] header : char( 3) ? [no] yes internal: 91/05/16 vs 91/05/17: diff 25 km (avg 17 km) internal: 91/05/17 vs 91/05/20: diff 28 km (avg 21 km) internal: 91/11/09 vs 91/11/10: diff 6 km (avg 4 km) internal: 91/11/10 vs 91/11/11: diff 5 km (avg 3 km) internal: 92/06/30 vs 92/07/01: diff 7 km (avg 7 km) internal: 93/06/30 vs 93/07/01: diff 7 km (avg 7 km) internal: 94/06/30 vs 94/07/01: diff 8 km (avg 8 km) internal errors: 7
If the input file is the orbinput from the ephemeris database, the external validation is meaningless because it will compare each record to itself.
Last Update: $Date: 1999/05/10 21:22:16 $