LASCO/EIT On-Board Observing Programs (LP)

An LP is software that has been designed to perform a particular task called observation program. The various LPs together provide the functionality of the OBE (observation Executive) which is the operating system of the LEB (LASCO/EIT Electronics Box) main processor. An LP may be scheduled to be performed at a particular time (delta from the current time) and to exit when a certain condition is met. Together the scheduled LPs form the various tasks that will be performed during the subsequent hours.

The following is a list of the currently defined LPs and a brief description of each.

Imaging LPs

Take Normal Image

This observation program is used to take normal images, using shutters, from C2,C3 and EIT. C1 images can be taken, but no commanding of the FP occurs.

Take FP Scan Line

This observation program is used to build a set of single Fabry-Perot wavelength images to obtain a complete line profile scan.

Wobble Inside FP Sequence

Take an image sequence using the C1 in dynamic imaging mode. The M1 mirror is moved to the four corners of a square, 1/2 pixel on a side, at each wavelength in a Fabry-Perot sequence.

Wobble Outside FP Sequence

Take an image sequence using the C1 in dynamic imaging mode. A full Fabry-Perot sequence is taken at each position of the M1 mirror. The M1 mirror is moved to the four corners of a square, 1/2 pixel on a side.

Take Polarization Sequence

This observation program will take a sequence of images at a given filter wheel position, but changing the polarizer (or sector) wheel position for each image.

Take inter-sum of images

This observation program is used to take normal images, from C2,C3 and EIT. C1 may also be imaged, but no FP commands are sent. An initial image is taken, and then subsequent images are added to or differenced from the image prior to transmission to the ground. The processing is determined by the contents of the image processing table.

Take Sequence of Images

This observation program is used to take a sequence of "normal" images from C1, C2, C3 and EIT. The desired sequence is specified by the input parameters.

Take Concurrent images

This observation program will take simultaneous (concurrent) images from one or more of the telescopes.

Block Schedule

This observation program use the preloaded schedule block to schedule LPs. The schedule block can contain up to 500 schedule commands. The schedule block command consists of a schedule type and time block and a set of LP parameters which are uploaded for later use.

Calibration LPs

Take Dark Current Image

This Observation Program is used to take dark images, from C1, C2, C3 and EIT. The filter, polarizer and shutter mechanisms are not moved.

Take calibration lamp image

This observation program is used to take internal calibration lamp images, possibly using shutters, from C1, C2, C3 and EIT.

Perform FP and Camera Coordinated Task

This observation program will perform various calibration functions of the FP which require a close coordination between the camera and the FP. These FP functions are scan central aperture, measure finesse, optimize finesse.

Take Pseudo-continuous Images

This observation program takes images using the pseudo-continuous mode, in which the image is read out while the shutter is open. Thus each pixel in a column on the CCD is exposed to the same scene. It is primarily used for CCD calibration.

Perform FP Check and Correct

This observation program is used to command the Fabry-Perot electronics to perform a check and correct algorithm of the FP to calibrate the correspondance between plate separation and wavelength.

Status LPs

Status Request Peripherals

This LP is used to explicitly solicit status from each peripheral (four cameras and the Fabry-Perot interferometer). Status will be obtained for the telescope that is being commanded by an imaging LP, and this LP will be automatically performed whenever the LEB is not performing some other LP.

Take M1 Measurements

Command the C1 M1 Measurement unit to turn on and return the values of the LVDTs and the M1 temperatures.

Dump memory

This observation program will send a memory dump from any of the LEB processors (OBE, TCE, ICE, PCE) down to the ground via the science telemetry channel.

Configuration LPs

Open/Close M1 Lid or Move DAC Positions

This observation program is scheduled to either move the M1 DACS to a commanded position or to open / close the M1 lid.

Process ground to peripheral cmnds

This observation program is used by the ground operator to explicitly command the camera or Fabry-Perot. Commanding of the camera and FP are normally done by the imaging LP. This LP is only used to configure a camera or FP into a mode that is not normally needed.

Process loading of peripherals

This observation program is used to load software into the five peripherals (cameras and FP). This is not normally used directly by ground command.

Parameter Table LPs

Load Default Camera Parameters

This observation program enables one of the three parameter tables (primary, alternate, or calibration) for a camera to be modified at a specific time in the schedule.

Schedule Mechanism Command

This observation program will command a mechanism motion at the scheduled time. Filter wheel, polarizer wheel, sector wheel and shutter motions are commanded from within an observation program, but other mechanisms (door, focus, etc) are not.