Instrument Software Reference

This section provides a description of the functions that are available through the LAI-2200C Control Unit software.

1 Wand Setup

Select Wand X (name) or Y (name).

1.1 Set Name

These fields are used to name the optical sensors. When an optical sensor is named, the name is stored in the optical sensor. For example, if an optical sensor is attached to the X port and named “PCH3102”, and later attached to the Y port, it will still be called “PCH3102”.

1.2 Clock

1.2.1 Set

The Set function is used to manually enter the time for the optical sensor clocks (HH:MM, YYYY/MM/DD).

1.2.2 Sync

The Sync function sets the optical sensor clock based on the control unit clock. Presents Yes/No verification.

1.3 Cal Values

Calibration multipliers are set from this field. Use the arrow and numeric keys to enter calibration values. Press OK to store the values. These values should match the calibration sheet.

1.4 Match Values

These functions pertain to the match values for the selected wand.

1.4.1 View / Set Values

View/Set allows you to view and/or edit the current values, or reset them to the calibration values by pressing LOG.

1.4.2 Compute Values

Two wands must be connected for this. The wand selected when entering the menu will be matched to the other. Compute will determine the values by measurement: You will need a second wand connected to do this, and both wands positioned and stable, viewing the same view of the sky (Don't do this indoors with artificial light, or looking out a window - tiny variations in views can cause large errors in those environments.) When you select "Yes", the match will be performed.

1.5 Auto Log

1.5.1 On/Off
1.5.2 Start Time
1.5.3 Stop Time
1.5.4 Frequency

Auto Log and the subsequent menu options are used to configure automatic logging, start time, stop time, and frequency.

2 Log Setup

These settings apply to new data, not existing data.

2.1 Transcomp

2.1.1 Define above:

This field defines how the sensor determines which readings are above-canopy and which are below-canopy.

Compare: The console will compare adjacent records to determine which type (A or B) has consistently higher values for active (non-masked) rings. That type will then be considered the above-canopy record type.

A: Means that readings taken while the optical sensor “Above” LED is illuminated will be considered above-canopy readings when calculating LAI.

B: Readings taken while the optical sensor “Above” LED is not illuminated will be considered below-canopy readings when calculating LAI.

2.1.2 Determine Above:

This field defines how the sensor uses above-canopy readings when computing LAI.

Previous: Uses the previous above-canopy record in the file to compute LAI.

Interpolate: Interpolates between two closest-in-time above-canopy records to generate each required above-canopy record. This is particularly useful when sky conditions are changing rapidly.

Closest: Associates each above-canopy record with the closest below-canopy record (in time) to compute LAI.

2.1.3 Bad Readings:

Bad readings occur when a below reading exceeds the value of a corresponding above reading (see page Bad Readings). There are two options:

Skip: The instrument will beep if a below reading has transmittance >1.0. It will log the below reading, but it will not use the record when computing LAI.

Clip: The transmittance for that ring in that record will be taken to be 1.0 when LAI is computed.

2.2 Prompts

Prompt1:

Resp1:

Prompt2:

Resp2:

Set prompts to prompt the user for additional information that will be recorded with each data file.

2.3 Obs Remarks

Remarks can be entered for each logged record. Remarks are set at this menu level or changed for individual records by entering the Log Setup menu while in logging mode. Changes to the remark are saved with each subsequent data file.

2.4 Angles

2.4.1 Sensor Angles:

1: 7.00

2: 23.00

3: 38.00

4: 53.00

5: 68.00

Angles in these fields are set to reflect the view of each ring in the sensor.

2.5 Distances

2.5.1 Distance Vectors

1: 1.008

2: 1.087

3: 1.270

4: 1.662

5: 2.670

The values are the average path length each ring sees through the canopy. By default, the values are 1/cos θ. For large, flat uniform canopies, this is sufficient; canopy height does not matter. For isolated canopies, the values should represent actual path lengths in meters.

2.6 Masks

2.6.1 Use Ring

Ring1: <YES | NO>

Ring2: <YES | NO>

Ring3: <YES | NO>

Ring4: <YES | NO>

Ring5: <YES | NO>

Determines which rings are used in LAI calculations. To exclude a ring, set its value (use ← and →) to No. To reset (all rings to Yes), press the LOG button while viewing this screen.

2.7 Controlled Sequence

Use: Yes|No

Reps: up to 41

Pattern:

2.8 Console AutoLog

Active: < On | Off >

Period: xx

The logging period can be entered in multiples of 5 seconds with a maximum of 3600 seconds (1 hour).

2.9 PAR Sensors

2.8.1 Port 1
2.8.2 Port 2

Enabled: < On | Off >

Name: Port 1

Cal: xxxxx

These fields are used to configure LI-COR radiation sensors. Enable the port by selecting On, Name the sensor, and enter the calibration multiplier for the sensor.

2.10 GPS

Active: < On | Off >

Log GPS: < Yes | No >

When: < A | B | Any >

3 Data

3.1 Console Data

3.1.1 Select data file:
3.1.1.1 Quick View

Shows the file header, which includes the file name, time and date created, responses to prompts, LAI, SEL, ACF, MTA, SEM, DIFN, and SMP (sample size). This also shows GPS information if the GPS is on.

3.1.1.2 View

3.1.1.2.1 View Header

Shows file name, time and date created, responses to prompts, LAI, SEL, ACF, MTA, SEM, DIFN, and SMP (sample size). This also shows GPS information if the GPS is on.

3.1.1.2.2 View ANGLES/MASK

Shows angles and masks used to compute the selected data file.

3.1.1.2.3 View CNTCT #/STDDEV

Shows contact number and standard deviation computed for the selected data file.

3.1.1.2.4 View AVGTRANS/GAPS

Shows average transmittance and gap fraction computed for the selected data file.

3.1.1.2.5 View DISTS/ACFS

Shows distances and apparent clumping factors for each ring.

3.1.1.2.6 View Observations

Shows ring values for each above and below reading in the file. Use the left/right arrow keys to scroll through readings.

3.1.1.3 Edit

These options pertain to the selected data file only.

3.1.1.3.1 Edit Angles

Sensor Angles: Edit the angles used in computations. Press OK to save new settings, EXIT to cancel, and LOG to reset to default settings.

3.1.1.3.2 Edit Mask

Use Mask: Apply a mask to any ring that is not to be used in computations. Press OK to save the new settings, EXIT to cancel, and LOG to reset to default values.

3.1.1.3.3 Edit Distances

Distance Vectors: Change these values to alter distances used in computations. Press OK to save the new settings, EXIT to cancel, and LOG to reset to default values.

3.1.1.3.4 Edit Transcomp

Use this field to change how the instrument defines above-canopy readings, determines above-canopy readings, and treats bad readings. A full description is in section 2.1 above.

3.1.1.3.5 Import Observations

This function can be used to import A or B records from another file.

3.1.1.3.6 Strip Observations

This function can be used to remove all A or B records from a file.

3.1.1.4 Recompute

Recomputes values for the selected data file. Use if any changes have been made to the file.

3.1.1.5 Delete

Permanently deletes the selected file.

3.1.1.5 Rename

Prompts for a new file name for the selected file.

3.2 Wand Data

3.2.1 Download – to transfer data from the wand to the control unit.

3.2.2 Purge – to delete data files from the wand.

4 Console Setup

4.1 Set Time

4.1.1 Console Time

Prompts for time and date. Use the up and down arrow keys to set time and date, or set via GPS UTC if available.

4.2 Auto Off Timer

Set the duration that the control unit will remain “On” before powering off automatically. The auto off timer can be set to 5-60 minutes in increments of 5 minutes using the up/down arrow keys.

4.3 Beeper

Turns the instrument beeper “On/Off”. Select the desired setting and press OK.

5 Firmware

5.1 Console

5.1.1 Info
5.1.2 Upgrade

See page Console Firmware for details.

5.2 Wand

5.2.1 Info
5.2.2 Upgrade

See page Optical Sensor Firmware for details.