Control Parameters

In Table 1 an overview of the control parameters of the aspect solution object is given. Reconstructing an image, the aspect solution control parameters suppose to have reasonable default value. Nevertheless, there are various circumstances where the aspect solution has to be controlled in more detail.

Table 1: The control parameters of the aspect solution object.

Parameter Name	Short Description	Default Value	Units
ASPECT_CNTL_LEVEL	control levels between -2 and 10	0	-
ASPECT_TIME_RANGE	optional time range	obs_time_int	anytim
RAS_TIME_EXTENSION	extension of time range for RAS	[-1400,+1400]	second
ASPECT_SIM	use simulated pointing	0	-
SASZERO	use pointing (0,0)	0	-
AS_SPIN_PERIOD	S/C spin period	4.0	second
AS_ROLL_OFFSET	roll angle at beginning of file	0.0	radian
AS_ROLL_SOLUTION	select mode of roll solution	'DBASE'	-
AS_NO_EXTRAPOL	allow/deny extrapolation of data	1	-
PMTRAS_DIAGNOSTIC	levels of diagnostics for PMTRAS	0u	-

1. ASPECT_CNTL_LEVEL. At various places of the aspect solution software error messages or warnings are produced, quality control values are calculated and plots are generated. With the control parameter 'aspectcntl_level' level of controlling outputs can be selected. By default, aspect_cntl_level is set to zero, which print errors and some warnings to the IDL log window. The Table 2 shows the valid settings and their results. In general, the higher the parameter is set, the more controlling messages, values and plots are generated.
   

   Table 2: The valid values of the control parameter ASPECT_CNTL_LEVEL.

   -2	no Errors and no Warnings
   -1	no Warnings
   0	write Errors and Warnings
   1	write some info to log window
   2	write more info to log window
   3	plot aspect solution
   4	calculate quality (radii, triangle ...)
   5	calculate quality, but no aspect plots
   6	plot quality, but no aspect plots
   7	aspect and quality plots
   8	aspect and more quality plots

   
   
2. ASPECT_TIME_RANGE. With this control parameter, the time range can be specified, for which an aspect solution has to be calculated. In general, it's set automatically to a reasonable value. In particular, it can be useful to specify an aspect time range if an aspect solution object is defined by giving a filename. The 'aspect_time_range' has to be set to a valid 'anytim' format.
3. RAS_TIME_EXTENSION. A two element vector of delta times in seconds that specify the extension of the aspect time range to be used to calculate the roll solution. The first value is added to the beginning and the second is added the end to the time range. Therefore, the first value suppose to be a negative and the second a positive number. Currently, the aspect time range with the ras time extension can not exeed the observation time interval by more the 1400 seconds. The default value is [-1400,1400].
4. ASPECT_SIM. This control parameter is a flag, which is used to switch between the reconstructed aspect solution from the aspect packets and a simulated aspect behavior. The default value is zero, which means that the software reconstructs the aspect solution from the packets. Setting the value to 1 produces a simulated aspect behavior.
5. SASZERO. Setting the control parameter saszero to 1, forces the pointing vector to be constant at [0,0]. This does not affect the roll solution.
6. AS_SPIN_PERIOD. With this control parameter, spin period of the aspect solution can be controlled. It has to be given in seconds per revolution. This spin period is used for the simulated aspect behavior and for the case where as_roll_solution is set to 'FIX' (see below).
7. AS_ROLL_OFFSET. In the case where as_roll_solution is set to 'FIX', the roll angle is set to as_roll_offset at the beginning of the accessed file.
8. AS_ROLL_SOLUTION. By this parameter, the method of the roll angle solution can be chosen. Currently, the values given in Table 3 are valid.
   

   Table 3: The valid values of the control parameter AS_ROLL_SOLUTION.

   'DBASE'	read roll solution from the provided database
   'FIX'	fixed spin period, use AS_SPIN_PERIOD and AS_ROLL_OFFSET
   'PMT'	use the PMTRAS to generate the roll solution
   'RAS'	use the CCD-RAS to generate the roll solution

   
   
9. AS_NO_EXTRAPOL. By default, the user is prevented from using aspect data point, which had to be extrapolated from measured data points. By setting this control parameter to 0 (zero), the software returns all measured data points within the aspect time range. If the keywords THIS_UT_REF, THIS_TIME and THIS_UNIT_TIME are used, the requested data points outside the aspect time range are extrapolated. In general, extrapolated data points can't be used for any data analysis.
10. PMTRAS_DIAGNOSTIC. By setting this parameter to a nonzero value, the PMTRAS software will print various information on the log window and produce various plot windows for diagnostic purposes. See the PMTRAS documentation for further information.