THEMIS Planning Layer

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The THEMIS Planning Layer, which is only available in the THEMIS release of JMARS, allows mission planners to plan observations for the THEMIS camera aboard Mars Odyssey. Only THEMIS team members with additional permissions can access the Planning Layer.

[edit] Loading the THEMIS Planning Layer

1. Open the Planning Layer: In the Layer Manager, chose "Add New Layer" -> "THEMIS Planning"
2. Enter Planning Properties: A number of parameters must be set before the THEMIS Planning Layer can open:

• Pre-Orbit: An input reserved for software testing.
• Minimum Orbit: The first orbit for which the user is planning or viewing observations. (Required)
• Maximum Orbit: The last orbit for which the user is planning or viewing observations. (Required)
• MMC Baseline: The known or predicted amount of data (in MB) in the MMC at the beginning of the given orbit range. (Not Required)
• Owners: The users whose observations should be displayed. (Only one user required, additional comma-seperated users are optional.)

3. Load the Planning Layer: Clicking the "OK" button will display the THEMIS groundtracks for the given orbit range in the Viewing Window and will open the "THEMIS Planning" tab in the Layer Manager.

[edit] THEMIS Planning Layer Functions

The functions of the THEMIS Planning Layer can be accessed by clicking on the "THEMIS Planning" tab in the Layer Manager, which provides access to the following four function tabs.

1. Settings Tab

• Orbit Settings

These options allow the user to change the Pre-Orbit, Orbit Range, MMC Baseline and Username which were set when the Planning Layer was opened. The "Reload" button must be clicked after any changes are made in order to update the information displayed in the Viewing Window.

• Groundtracks

These options allow the user to add or remove the displayed groundtrack in either the Main or Panning Views and change the color and transparency of both the selected and unselected groundtracks. Users are also given the option to filter the groundtracks so only certain parts are visible, such as Day or Night (determined by illumination level) and Descending or Ascending (descending=traveling north to south, ascending=traveling south to north).

• Observations

These options allow the user to add or remove the displayed observations from either the Main or Panning Views and to change the colors assocaited with different types of observations.

• Miscellaneous

• The "View Follows Ruler" option will re-center the Main and Panning Views to run parallel to a selected groundtrack. This replicates (although not exactly) the old JMARS Time Mode.
• The "Show Off-Nadir" option will show any off-nadir slews that have been planned. The nominal groundtrack will be represented by a broken line and the off-nadir THEMIS groundtrack will be represented by a solid line.
• The "Show Downlink Cues" option will add grey shading to the OPTG ruler to represent periods where ODY is downlinking, so the mission planners can try to avoid planning off-nadir slews during those times.

2. Tooltips Tab

• Time Formats

These check boxes allow the user to chose which time format is displayed in the tooltip when the cursor is placed on a groundtrack. Multiple time formats can be chosen.

• Additional Tooltip Information

These check boxes allow the user to add additional information to the mouse-over tooltip.

3. Observations Tab

• Observations List

The table in the Observations Tab lists all observations in the given orbit range along with their various parameters. Users can sort the observations according to the parameters by clicking on the parameter names. Observations selected in the Viewing Window will be highlighted. At the bottom of the table are some basic statistics: the number of commands required for the observations, the number of observations, number of selected observations, number of modified observations and the number of observations in conflict with other observations.

• Description:

All THEMIS observations, VIS and IR, can be given descriptions. Usually these are used to describe the region being observed or the imaging campaign that targeted the observation.

• IR Properties:

• Start Time: The start time of the image given in ephemeris time (et).
• ILen: The duration of the IR observation. (ILen = 7 = 1 minute)
• Observation ID: A placeholder with a default value of "255". The official ID will be automatically generated when the observation is finalized before uplink to THEMIS.
• Gain: A placeholder with a default value of "16". Appropriate gain values will be automatically generated when the observation is finalized before uplink to THEMIS.
• Offset: A placeholder with a default value of "99". Appropriate offset values will be automatically generated when the observation is finalized before uplink to THEMIS.
• Summing: A summing value between 1 (full resolution) and 160 (lowest resolution).
• Rice: Enables/Disables rice compression of the observation before downlink. The default value is "Enabled".
• TDI: Enables/Disables the time delay and integration (TDI) mode. The default value is "Enabled".
• Cal: Indicates whether or not the IR observation is a Calibration Image.
• Shutter: Indicates whether or not the IR observation is a Shutter Image.
• Bands: Sets the band configuration of the IR image using pre-set configurations.

• VIS Properties:

• Start Time: The start time of the image given in ephemeris time (et).
• Frames: The duration of the image given as the number of frames.
• Observation ID: A placeholder with a default value of "255". The official ID will be automatically generated when the observation is finalized before uplink to THEMIS.
• Interframe Delay: The time delay between frames. (The current optimum setting is 0.9s)
• Exposure: The length of the exposure in tenths of a millisecond, which can be either automatically calculated by clicking the "Calc Exp" button or manually entered.
• Summing: A summing value of either 1 (18m), 2 (36m) or 4 (72m) resolution.

Unlike the IR camera, the VIS camera only has three summing levels.

• Compression: A placeholder for the compression factor for the VIS image. The default value is "65535" and will be automatically replaced by appropriate compression values when the observation is finalized before uplink to THEMIS.
• Bands: Sets the band configuration using pre-set configurations.

4. Slews Tab

• Slew List

The table under the Slews Tab lists all slews that have been planned in the given orbit range along with their various parameters. Users can sort the observations according to the parameters by clicking on the parameter names.

• Slew Properties:

• Slew ID: A placeholder for the slew ID number, which will be assigned when the slews are finalized.
• Roll Angle: The angle of commanded roll about Odyssey's velocity vector in degrees with positive defined by the right-hand rule.
• Slew Start: The start time of the slew given in ET. The start time is defined as the beginning of the stabalized portion of the slew that can be used for imaging. The slew settling time before and after this stabilized portion is not included in the slew length measurements.
• Slew Duration: The length of the stablized portion of the slew in seconds.
• Touched: The last time that the slew database entry was modified. Once slews have been finalized, they cannot be edited.

[edit] THEMIS Planning Layer Rulers

The THEMIS Planning Layer also includes four rulers, which are displayed in the Viewing Window underneath the Panning View. (Note: If the Viewing WIndow is maximized when you load the Planning Layer, you will need to un-maximize the window for the rulers to appear.) The rulers behave similar to the Panning Window, but instead of displaying a wide-angle view of the maps they display other information related to the planning orbit range in chronological order. Clicking on an event in a ruler will automatically re-center the Main and Panning Views on that point.

If users are viewing the map with the "View Follows Ruler" option enabled the groundtrack will run parallel to the rulers, which can be synced with the Main View by adjusting their zoom levels. Otherwise, the position in the ruler does not necessarily correspond with the points in the Main and Panning Views above it. In this case, when the mouse cursor is in a ruler, a red set of crosshairs will appear in the Main and Panning Views at the corresponding location. Users also have the option to hide some or all of the rulers by right-clicking on any of them.

Observations Ruler:

The Observations Ruler displays markers for all of the observations that have been entered in the given range of orbits. The markers are displayed in the same color as the observations they represent (ie: VIS images appear as green markers, etc).

This ruler also contains a thin line at the top of the ruler which tracks when slews occur. Yellow areas are where slews are allowable, the red araes are slew keepout zones and the green areas are planned or finalized slews.

OPTG Ruler

The OPTG Ruler displays markers for certain events in each orbit, which are explained below. This data is obtained from the weekly OPTG file that should be updated before any THEMIS planning is done.

• DEQUAX - Descending Equator Crossing
• DLTERM - Dark-to-Light Terminator Crossing
• FKSUNX - Fake Sun Crossing (Crossing the Sub-Solar Latitude)
• LDTERM - Light-to-Dark Terminator Crossing
• NPOLEX - North Pole Crossing
• SPOLEX - South Pole Crossing

If the "Show Downlink Cues" option is enabled in the "Settings" tab all downlink periods will appear as grey areas on the ruler. This helps the mission planners avoid commanding a slew during a communications pass, which could significantly reduce the amount of the data that Odyssey can send back.

Angle/Time Ruler

The Angle/Time Ruler displays graphs of the solar incidence angle (red) and the local time on the surface (blue). The exact numerical values of both are displayed in a tooltip when the mouse cursor is placed on the ruler.

MMC/Downlink

The MMC/Downlink ruler displays the amount of data collected during the given planning range and the amount of downlink scheduled during the same period. In order to prevent filling or emptying the THEMIS mass memory card (MMC), planners usually only collect enough data to fill the daily downlink, preventing any net change in the total amount of data on-board. If there is already data on the MMC, planners can enter this number in the "MMC Baseline" field when opening the planning layer so they can ensure they will not fill the MMC during their planning range.

[edit] Inserting a VIS Observation

Open the THEMIS Planning Layer: Using the instructions above, open the Planning Layer and select it as the active layer in the Layer Manager.

Insert a VIS Observation: In the Main View, right-click on the groundtrack at the location where the VIS observation will begin and select "New Observation" and chose from one of the available VIS observation types.

• VIS 1 Band: A band 3 (RED) 18m resolution observation. This is the most common type of VIS image and is the type used for high-res mapping.
• VIS Color: A four band (2,3,4,5) 18m resolution observation. This is the most common multiband image and can be used to produce approximate true-color images.
• VIS Polar: A band 3 (RED) 36m resolution observation, most commonly used for the polar monitoring campaigns and large-area mapping.
• If the desired VIS observation type is not in the list, chose the closest one and then edit the parameters in the focus panel manually.

Adjust VIS Observation Location: If the observation needs to be re-positioned, left-click and drag the observation to a new location.

Adjust VIS Observation Parameters: Users must always set the image exposure by selecting the image and clicking the "Calc Exp" button in the focus panel. Mission planners may occasionally need to adjust some of the other parameters manually.

Commit the Observation: To add the observations to the database, right-click anywhere in the Main View and chose "Commit All Changes".

• Even if you have access to the Planning Layer, only mission planners are able to commit observations to the database. All other users will get an error.

[edit] Inserting an IR Observation

Open the THEMIS Planning Layer: Using the instructions above, open the Planning Layer and select it as the active layer in the Layer Manager.

Insert an IR Observation: In the Main View, right-click on the groundtrack at the location where the IR observation will begin and select "New Observation" and chose from one of the pre-set IR observation lengths

• 1 minutes = 7 ILen
• If the desired observation length is not on the list, chose the closest one and edit the ILen manually in the focus panel.
• The preferred maximum length of a THEMIS IR observation is 8 min (ILen=56).

• Longer IR images are difficult to properly process and calibrate.

Adjust IR Observation Location: If the observation needs to be re-positioned, left-click and drag the observation to a new location.

Adjust IR Observation Parameters: Usually users will only need to adjust the ILen (if necessary) and the band configuration. Mission planners may occasionally need to manually adjust some of the other parameters.

Add an Embedded VIS: THEMIS has the ability to take a VIS and an IR observation simultaneously. If desired, the user can select the IR observation, right-click, select "New Observation" and select the desired VIS image type. The VIS image can then be moved within the IR image and its parameters can be edited like normal.

• Don't forget to click "Calc Exp" to calculate the VIS image's exposure.

Add Calibration and Shutter Images: All IR observations need to be accompanied by properly positioned calibration and shutter images in order for the image to be processed and calibrated correctly. To add these images, select the IR observation in the Main View, right-click on the observation, chose "Autodrop" and chose "Create Both Auto Cal and Shutter".

• Users can also drop a Cal or Shutter image by itself if necessary by choosing those options under "Autodrop".

Commit the Observation: To add the observations to the database, right-click anywhere in the Main View and chose "Commit All Changes".

• Even if you have access to the Planning Layer, only mission planners are able to commit observations to the database. All other users will get an error.

[edit] Inserting a Slew

Open the THEMIS Planning Layer: Using the instructions above, open the Planning Layer and select it as the active layer in the Layer Manager.

Insert a Slew: In the Main View, right-click on the groundtrack at the location where the slew will be centered and select "Create Slew".

• The nominal nadir groundtrack will now appear as a dashed line.
• The stable position of the off-nadir slew will appear as a solid line. Normally, all imaging will taking place in this portion of the slew.
• The non-stable portions of the off-nadir slew will appear as dotted lines on both sides of the stable portion. Although imaging during these periods is allowed, the spacecraft will be actively rolling and imaging is not recommended.

Adjust Slew Location: The size and location of the slew can be changed by doing a left-click and drag on the two sidebars that bound the stable portion of the slew.

• The sidebars must be moved individually.
• As the sidebars are moved, the unstable portion of the slew will move as well. Make sure you don't expand the ends of the unstable periods over any existing observations.

[edit] Copying an Observation

Select Observation(s): To select a single observation, left-click on it. To select multiple observations, left-click on them while holding the Ctrl key.

Copy the Observation(s): Right-click on one of the selected observations and chose "Edit" -> "Copy"

Paste the Observation(s): Right click on the groundtrack at the location where you wish to paste the observations, chose "Edit" and then either "Paste with Start at ET:#########" or "Paste with Center at ET:#########"

Commit Observations: Right-click anywhere in the Main View and chose "Commit All Observations"

[edit] Grouping Observations

Select Observations: To select multiple observations, left-click on them while holding the Ctrl key.

Group the Observations: Right-click on one of the selected observations and chose "Group". Once grouped, the observations will behave as if they were a single observation. They can be moved, copied and pasted without the relative spacing between them changing. When pasted, the new copy will be grouped by default.

Commit Observations: Right-click anywhere in the Main View and chose "Commit All Observations"

Ungrouping the Observations: Right-click on the group of observations and chose "Ungroup". The observations will now behave as individual observations again.