Data Collection

GNSS-INS

Applanix APX-15 begins recording data once system is powered and sensor is initialized (~10-60 seconds after power on when there are no obstructions to satellites).

Immediately after takeoff and prior to the survey start, a Dynamic Alignment Procedure for Applanix APX-15 must be performed. The Dynamic Alignment Procedure must also be performed immediately after survey conclusion, prior to landing.

The Dynamic Alignment Procedure shall include:

• >5m/s horizontal acceleration for 5-10 seconds, and then quickly come to a hover with maximum deceleration

• >5m/s horizontal acceleration for 5-10 seconds in the opposite direction, and then quickly come to a hover with maximum deceleration

Users should perform the dynamic alignment procedure as close as possible to the survey start point.

NanoHP VNIR

Through HSInsight (or Hyperspec III), users should:

1. Set Frame Period based on GRYFN's Flight Planning Calculator.

2. Open Live Video with exposure reference panel below lens.

3. Set exposure/gain modes to maximize spectral saturation.

   1. Typically peak of spectral curve should reach 95% saturation, but users may need to adjust based on content of their scene.

4. Upload capture polygon

   1. If applicable to your operations, set the minimum and maximum polygon altitudes based on current elevation and flight elevation. Allow 5-10m of buffer, at minimum, above and below flight altitude.

5. Collect dark reference with lens cap on.

6. Start collection with GPS triggering enabled.

NanoHP VNIR sensor begins recording data after the Start/Go button has been pressed in HSInsight/Hyperspec III AND when the sensor is inside the HSI capture polygon, laterally and vertically.

SWIR 640

The SWIR640 must be properly cooled before the sensor can be initialized. The Stirling cooler will cool the sensor to -40C. An audible click can be heard when the sensor is cool enough to initialize. Once the sensor is properly cooled, users may configure collection parameters and begin operations.

Through Hyperspec III, users should:

1. Set Frame Period based on GRYFN's Flight Planning Calculator.

2. Open Live Video with exposure reference panel below lens.

3. Set exposure/gain modes to maximize spectral saturation.

   1. Typically peak of spectral curve should reach 95% saturation, but users may need to adjust based on content of their scene.

4. Upload capture polygon

   1. Note current ground elevation for use with Z component of polygon.

5. Collect dark reference with lens cap on.

6. Enable GPS triggering.

7. Set the minimum and maximum polygon altitudes based on current elevation and flight elevation. Allow 5-10m of buffer, at minimum, above and below flight altitude.

8. Start collection with GPS triggering enabled.

SWIR 640 begins recording data after the Hyperspec III Go button has been pressed AND when the sensor is inside the HSI capture polygon, both vertically and laterally.

3D LiDAR

Velodyne VLP-16 LiDAR sensor begins recording data once the ethernet cable has been plugged into the VNIR port on the Co-Aligned, after the VNIR capture has been started.

Flight Operations

IF1200A + CoAligned

PARAMETER	DESCRIPTION
Flight Time	~30 minutes
Mission Time	~ 26 minutes (accounts for takeoff, landing, GNSS alignment)
30m Flight 3m/s, 8m spacing	VNIR: 1.4cm SWIR: 1.8cm Coverage: ~8 acres
60m Flight 5m/s, 15m spacing	VNIR: 2.8cm SWIR: 3.6cm Coverage: ~26 acres
120m Flight 8m/s, 30m spacing	VNIR: 5.6cm SWIR: 7.2cm Coverage: ~75 acres

*Flight speeds beyond 8m/s, regardless of mission altitude, will begin to cause alignment issues between adjacent tracks in both hyperspectral sensors due to the heavily increased forward pitch of the aircraft.

Please see Operating Hyperspectral Line-Scanners for information on flight parameters and how they relate to sensor framerates and sampling rates.

Parameter Setting Workflows