Automatic gain control and logarithmic quantization were used to handle the
unknown dynamic range of illumination. The raw image was converted to
optical density according to Russian calibration data, then to linear
radiance for image processing. It was interpolated with windowed sinc
filter to avoid post-aliasing (a "pixilated" appearance), and the modulation
transfer function ("aperture") of the camera was corrected with a 1 +
0.2*frequency**2 emphasis. This was then written out as 8-bit
gamma-corrected values, using the sRGB standard gamma of 2.2.
(Venera 9 Lander, corrected surface image)
(Image posted with permission, copyright 2003 Don P. Mitchell. All rights reserved.)
Larger image ( 82K)
High resolution tiff file (228K)
Location & Time Information
Date/Time (UT): 1975-10-22 T 05:13
Distance/Range (km): 0.002
Central Latitude/Longitude (deg): +32.,291. E
Orbit(s): lander
Imaging Information
Area or Feature Type: surface, lander
Instrument: Television Camera (Panoramic Telephotometer)
Instrument Resolution (pixels): 128 x 512, 6 bit
Instrument Field of View (deg): 170. (horizontal)
Filter: N/A
Illumination Incidence Angle (deg): N/A
Phase Angle (deg): N/A
Instrument Look Direction: N/A
Surface Emission Angle (deg): N/A
Ordering Information
CD-ROM Volume: N/A
NASA Image ID number: Venera 9 lander corrected image
Other Image ID number: N/A
NSSDC Data Set ID (Photo): 75-050D-01A
NSSDC Data Set ID (CD): N/A
Other ID: N/A
![[NASA Logo]](/logo/nasa_logo.gif){kind=logo}
Authors/Curators:
Dave Williams, dave.williams@nasa.gov, (301) 286-1258
Code 690.1, NASA Goddard Space Flight Center
Greenbelt, MD 20771, USA
Jay Friedlander, jay.s.friedlander@nasa.gov, (301) 286-7172
Code 612.4, NASA Goddard Space Flight Center
Greenbelt, MD 20771, USA