Leica RCD105 digital camera

The RCD105 is a medium-format digital camera which is integrated together with the Leica ALS-50 Lidar system.

Raw data format

The RCD105 data are captured in compressed 12-bit .raw files of approximately 57MB size. To accompany the .raw files, various ASCII header files are generated. The most useful of these is the image events file which contains time stamp information for each photograph, including real-time aircraft position and attitude data.

The raw file name convention is: DDHHMMSSXXXXXXGN.raw

• DD = day of month
• HHMMSS = timestamp
• XXXXXX = incrementing picture id
• G = gain (1-4)

Calibrations

The RCD system is calibrated at Leica every 2 years. The latest calibration certificates are included here:

• February 2010
• July 2008

The raw calibration files include dark values, gains and camera parameters.

Specifications

Detector size	39 Mega-pixels @ 7216x5412 resolution
pixel size	6.8 microns giving ~15cm resolution at 1350m flying height
lenses	60mm (changeable) with 44.2 degree x 34.0 degree FOV
aperture	fixed f-4.0
exposure time	up to 1/4000
Maximum frame rate	0.5 Hz

The shutter is a dual curtain, one opening to start the exposure and the other closing to finish it.

• exposure will therefore occur at different times along the focal plane
• 8ms for shutter to open and close, so there's a 4ms time difference between the top and bottom of the CCD acquiring light

Lens distortion is a maximum of 2% at the edges of the field of view.

• distortion measurements are available

The CCD is a Bayer array (raw 7162 x 5389), with a pixel layout as below. In the final processed TIFF, these pixels are blended and interpolated to make a full RGB grid.

Blue	Green
Green	Red