AIPS HELP file for OBEDT in 31DEC25
As of Wed Dec 11 9:07:17 2024
OBEDT: Task to flag data of orbiting antennas
INPUTS
INNAME Input UV file name (name)
INCLASS Input UV file name (class)
INSEQ 0.0 9999.0 Input UV file name (seq. #)
INDISK 0.0 9.0 Input UV file disk unit #
INVERS 0.0 9999.0 Input OB table version
0 => last
TIMERANG Time range to use. 0=>all
SUBARRAY Subarray number; 0 => 1
OPCODE Parameter used to control
the flagging
' ' => 'DIST'
APARM Control information:
1 : lower limit of the param.
2 : upper limit of the param.
The data are flagged if the
selected parameter is between
these two.
If AN table is not filled by
the parameters for the orbit.
antennas and there is no OB
tab., the orbit is determined
by the six parameters:
3 : Semi-major axis (m)
4 : Eccentricity
5 : Inclination of the orbit
plane to equator, deg.
6 : RA of the ascending node,
deg.
7 : Angle of perigee to the
ascending node, deg.
8 : Mean anomaly at the
reference time, deg.
9 : step in time, seconds
0 => 10sec
FLAGVER Version of the FG table.
0 => the new one
BADDISK Disks to avoid for scratch
HELP SECTION
OBEDT
Task: The task reads antenna table (AN) or an orbiting table (OB),
checks the value of the selected parameter, compares it with the
selected lower and upper limits and flags the data of the
orbiting antennas if the parameter is between the limits.
Adverbs:
INNAME.....Input UV file name (name). Standard defaults.
INCLASS....Input UV file name (class). Standard defaults.
INSEQ......Input UV file name (seq. #). 0 => highest.
INDISK.....Disk drive # of input UV file. 0 => any.
INVERS.....Input OB table version; 0 => last
TIMERANG...Time range to use; 0=>all
SUBARRAY...Subarray number; 0 => 1
OPCODE.....'DIST' - the distance of the satellite from the Earth
center, km
'VEL ' - speed of the satellite, km/s
'SUNS' - Angle of the Sun from the source, degrees
'ECLB' - Time from the beginning of the previous eclipse
of the Sun, hours
'ECLE' - Time from the end of the previous eclipse
of the Sun, hours
' ' => 'DIST'
APARM.....Control information:
1 : Lower limit of the parameter in units corresponding to
OPCODE
2 : Upper limit of the parameter in units corresponding to
OPCODE
The data are flagged if the selected parameter is between
these lower and upper limits.
If AN table is not filled by the parameters for the orbiting
antennas and there is no OB table, the only orbit
is determined by the following six parameters:
3 : Semi-major axis (m)
4 : Eccentricity
5 : Inclination of orbit plane to equator, deg.
6 : RA of the ascending node, deg.
7 : Angle of perigee to the ascending node, deg.
8 : Mean anomaly at the reference time, deg.
9 : Step in time, seconds. Condition of flagging is checked
under control APARM(1), APARM(2) at the time with
the time step APARM(9)
0 => 10 sec
FLAGVER...Version of the FG table. 0 => the new one
BADDISK....The disk numbers to avoid for scratch files (sorting
tables mostly).
Documenters: L.R. Kogan
PURPOSE
The orbiting VLBI provides some additional requirements which do not
have a place at the case of the classic ground based VLBI network.
For example the Sun can be eclipsed for the orbiting antenna and as a
result the battery will not be charged properly and the whole orbiting
hardware will not work properly. So the user can want to flag such data
in advance. He can want to flag data using another parameter (distance,
speed ..) as a criterium.
The OB table is the table including the relevant information about the
orbiting antenna. Using the OB table as a source of the information can
provide problem at the case of big gaps in time at the OB table.
To exclude the problem the task uses the AN table to read the six
parameters of the orbits. If the AN table is not filled out by the
orbits parameters, the task reconstructs the orbits using OB table data.
If OB table does not exist, an user can use the orbit determined by
APARM(3)-APARM(8). Having obtained the parameters of the orbits, the
task calculates the required value (OPCODE) for a time at the range of
the UV data with the step - APARM(9).
The thresholds are selected by APARM(1) and APARM(2).