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EdRPI: Mission planning tool for RPI

Contact:	Ivan Galkin
Started:	June 23, 1999
Last changed:	March 11, 2008

1. RPI Commanding Overview

The Radio Plasma Imager (RPI) is a versatile instrument with multiple operating modes that are continuously switched as the IMAGE spacecraft orbits the Earth. Direct commanding of RPI operations is not technically feasible: with a typical measurement run times of 2-3 minutes, direct commanding requires ~400 ground commands per orbit.

Instead of direct specification of each measurement start, we use a concept of a measurement schedule.

One schedule specifies a repetitive sequence of measurement programs, each program defining a particular RPI operating mode and its parameters. Once a schedule is started, the measurement program sequence is executed in a loop. Thus, RPI can be supplied with a set of schedules, each targeting a specific scientific goal, and switch them appropriately along the orbit.

Specification of the automated RPI operations therefore includes:

design of measurement programs,
assembly of programs into schedules, and
specification of schedule actual start times (in spacecraft MET, mission elapsed time).

Correspondingly, RPI instrument stores in its computer memory three control data structures:

64 Programs
32 Schedules
256 Schedule Start Times (SST)

It is expected that programs and schedules will eventually become stable, and only new SST tables will be occasionally uploaded to the spacecraft. The period of mission time when RPI does not require any new control data from the ground is called a "lights-out" period. Typical light-out period for RPI is 2 weeks.

If by the end of a lights-out period no new SSTs are available to further execute measurement schedules, RPI runs the last schedule in the list.

For further information please refer to RPI Commanding document.

2. EdRPI Installation

EdRPI is provided as a part of the RPIAnywhere software suite, available for download at UMLCAR webpage.

3. Working with EdRPI v2.1

EdRPI is a utility capable of editing RPI control data sets and exporting them as ASIST scripts suitable for uploading to IMAGE. EdRPI works with a single "RCD" (RPI Control Data) file containing programs, schedules and SSTs that are individually timestamped, entitled and supplied with a contact person information. All RCD files are kept under strict version control.

3.1. Updating to the latest versions

Before you begin, always make sure that the RCD files and EdRPI software are the latest. This especially concerns RCD files whose master copy is stored in the CVS repository at UMLCAR. If you make changes to your local copy of an RCD file whose master copy has been changed by somebody else, you will not be able to commit your changes to the master copy. Regretfully, at this time no reliable mechanism exists that would merge your changes to the master copy that was independently changes by somebody else. So please update your local copies of RCD files before you start changing them.

To update the local files to match the master files,

startup version control software, jCVS
Double-click on Weekly RCD project from your WorkBench.
Provide password (contact for the password)
From the Project menu, select Update.

3.2. Starting up EdRPI

Startup of EdRPI can take anywhere between 5 seconds and 1 minute. A progress bar is provided to monitor the loading process. After the loading is complete, the File menu becomes active, with two enabled items, New and Open. Use them to open existing RCD files or start a new set of RPI Control Data.

3.3. Editing programs with EdRPI

The Program Editor Panel consists of

the left panel with a Program List table and two buttons Undo and Save
the right panel with the Program Editor controls

Use the Program List to browse through the available (up to 64) programs. Program examples can be found in the RPI Commanding document. If you make changes to the program in the right panel, you will have to either save them, or undo them.

Saving a program does not update the current RCD file. You can save RCD file at any time from the File menu.

3.4. Editing schedules with EdRPI

The Schedule Editor Panel consists of

the left panel with a Schedule List table and two buttons Undo and Save
the right panel with the Schedule Editor controls

Use the Schedule List to browse through the available (up to 32) schedules. In each schedule, 60 entries are provided , arranged in three columns of grey buttons enumerated from 00 to 59. A program can be scheduled to run at any of the entries by clicking on the Entry # button. In the above example, schedule #19 specifies 6 minute schedule that sequentially runs 5 programs (#34, #28, #34 again, #23, and #26).

The program number is specifed inside the yellow text box. To fine tune the time of the program start, a text field is provided to specify the start offset in sec. The blue time label indicates the program start relative to the beginning of the schedule period. This time is equal to (Entry-# times Entry-Interval) plus Start-offset. The Entry-Interval is selected using the slider on the top of the schedule editor.

The estimated duration of the program is used to indicate portion of the Schedule Period taken by the program. If two programs are overlapping in time, the conflict will be shown in red. Programs can be removed from the schedule by another click on the Entry # button.

If you make changes to the schedule displayed on the right, you will have to either save them, or undo them.

Saving a schedule does not update the current RCD file. You can save RCD file at any time from the File menu.

3.4. Weekly updates of SST Table

New schedule start times (SST) are calculated every week (or 2 weeks) for upload to the RPI. EdRPI uses SST rules to calculate start times. For example, an SST rule can prescribe to start schedule #22 on the outbound section of each orbit as soon as IMAGE spacecraft is within 6 Re from the magnetopause. SST rules frequently use distances to plasmapause, magnetopause and orbit parameters such as perigee crossing time. In order for EdRPI to generate SSTs in accordance with the internal SST rules, it uses geospace model predictions and orbit data generated at NASA and stored in the RPI database at Lowell.

SST Editor

The SST Editor panel contains:

Calculated SST Table in the left panel,
Timeline chart showing RPI schedules and predicted geospace data in two panels (range and frequency), and
Manual SST editor and automatic switch point calculator

The SST Table in the left panel is the final product of mission planning; calculated SSTs are saved as an ASIST procedure script for upload to IMAGE. The automatic switch point calculator uses SST rules that are programmed in EdRPI software. In this particular example, RPI is programmed to use 6 different schedules per 14.5 hour orbit. Schedules are shown in the Timeline Chart by two different color groups (blue and pink), and individual programs are shown within each schedule by two color shades. The Timeline chart also displays predicted data such as plasma and gyrofrequency, L-shell, distances to plasma- and magnetopause, etc. There are three context "on demand" windows to show additional information for the MET at the mouse pointer position, two on the right side of the Timeline chart and one below the chart