TRANSFORMATION OF VENERA 13 AND 14 PANORAMAS INTO VIKING LANDER PERSPECTIVE
James 8 . Garvin, Paul Helfenstein, and Maria T. Zuber
Department of Geological Sciences, Brown University, Providence, R 1 02912
The Venera 13 and 14 spacecraft have provided images of the venusian surface at a resolution carparable to that of the Vlki
lander in survey
modeaIqO.l1. HCWver, to allow both nearfield and b#zon to be imaged using
a single viewing geanetry, the optical axis of the Venera lander imaging system was inclined relative to the plane of the surfacel,~. In order to evaluate the morphology and morphometry of geologic features at the Venera 13 and
14 sites, the panoramas have been transformed into a m r e familiar Viking lander perspective with 0' center elevation and 0.12' per pixel resolution. Analysis of the size-frequency distribution and morphology of fragments in Viking
images4,s has provided insight into formation, emplacement, and modification
history of rocks on the surface of Mars, and it Is hoped that a similar analysis of the transformed Venera 13 and 14 Images will aid in the geologic interpretation of these landing sites.
I t is instructive to s m r i z e the basic details of both the Venera and
Viking dig9tal facsimile imaging systems. The Venera 13. and 14 cameras used a
viewing geunetry with an inclination of 50'
a camera height of 0.9m, and a
at a hi her rate, at higher re40' vertical field of viewl0,ll. They scan&
solution (0.18* vs. 0.12. per pixel ) , and with m r e yevels of quantization
than the cameras on Venera 9 and 10~,10,11. The effective resolution on the
surface of Venus was 3.&nn/pixel at a slant range of 1.2m, which conpares with
Viking survey mode resolution of 3 . W at 1.6m, or to l.lmn in high resolution
modeS,*O. The viewing geametry of those Viking images taken with a center
elevation of -50' and survey mode diode (O.lZ*/pixel) is directly carparable
to Venera except that the Venera field of view is fixed at 40' fran the vertiThe Viking lander spacecraft and camera viewing
cal and 180' in azinuthlo.
geometry did not permit the horizon to be viewed at high center elevations,
and only the surface about the lander footpads c w l d be seen".
The Venera
.perspective was altered to that of Viking survey mode to preserve resolution,
and so the horizon in the transformed panorama w w l d be flat.
This geunetry
is particularly advantageous since i t allows arphometric analysis of the Venus surface features using presently available software developed for the study
of Viking images4,n.
In order to transform the Venera images, i t was necessary to process them
into conputer-carrpatible digital form. Enlarged Vemra 13 and 14 photographs
provided by Soviet scientists6 were digitized using an Optronics digital scanner'.
In the digitization procedure, the brightness of each Venera ima e pixgrey
el was sanpled at least once. and at the same level of quantlzation 12!6
levels) as in the original Vemra data. Each panorama was divided into 3 azimuthal sections and was transformed Into Viking lander'perspective using standard matrix rotation methods.
This technique is carpletely general and other
Florensky
have produced
perspectives can similarly be generated.
rotated Venera 9 and 10 ima s with flat horizons, however, not necessarily In
a Viki
perspective.
Arv dson' used a different approach in his analysis of
and 10 images by transforming Viki
lander 1 asaics into Venera
the Viking data (0.04'1 to that
perspective, while degrading the resolution
of Venera (0.35').
ene era?
!r
a a.l,lo
3
Figure 1 illustrates a Venera 14 panorama before I t has been rotated, while
Figure 2 chows the result of a perspective transformation of the Image in Figurd 1 at a slightly different contrast enhancement. We are currently in the
process of gathering data fran transformed Venera 13 and 14 panoramas, the
first of which is presented in (13). In addition, the Venera images are being
transformed into other perspectives such as polar grmmic' for further morphantric analysis.
We acknowledge Drs. V . Barshov mnd A.T. Basilevsky, and the Canparative Planetology Laboratory at the Vernadsky Instlt.
in Moscow for providing us with
the Venera photographs and Soviet ptblications on the details of the camera
~yStallS.
O Lunar and Planetary Institute
Provided by the NASA Astrophysics Data System
TRANSFORMATION OF VENERA PANORAMAS
Garvin, J
.
B. e t a l .
REFERENCES: ( 1 ) Keldysh M.V. ( e d . ) (1979) NASA TM-75706, 193 pp. ( c . f . F i g . 14, p. 150). ( 2 ) F l o r e n s k y
C. P. e t a l . (1977) GSA B u l l . 88, 1537. (31 Huck F. 0. e t a l . (1975) Space S c i . I n s t r . 1, 189. ( 4 ) G a r v i n
J . B. e t a l . (1981) The Moon and t h e P l a n e t s 24, 355. ( 5 ) G a r v i n J. 8. e t a l . (1981) NASA TM-84211, 177.
( 6 ) B a s i l e v s k y A.T. e t a l . (1982) Personal Comnunications, Moscow, USSR. ( 7 ) Chesley D. M. 1982 D i g i t a l
Image A n a l y s i s L a b o r a t o r y , UMlS, Amherst. ( 8 ) L e v i n t h a l I. and Jones K. (1980) NASA CR-3321, 98;~.
( 9 ) M c G i l l G.E. e t a l . (1983) i n Venus , Chapter 6 ( i n p r e s s ) ; s e c t i o n on t r a n s f o r m e d V i k i n g imaoes by
R. A r v i d s o n ( T a b l e 111, F i g s . 0).4)3,
F l o r e n s k y C. P. e t a1.(1982) Jour. o f A s t r o n . L e t t e r s 8 ( i n
Russian), 429. (11) F l o r e n s k y C. P. e t a l . (1982) A s t r o n . H e r a l d XVI ( i n Russian , 131.
12 Hutch T. A.
(1978) The M a r t i a n Landscape, NASA SP-425, Washington D. C . , 160 pp. (13) Garvi! J. B. e i a!. (1983)
LPSC XIV s u b m i t t e d a b s t r a c t .
Fig. (BEFORE) Venera 14 panorama o q Venus a c q u i r e d on March 5, 1982. The t r e l l i s g i r d e r ("arm") i s 60 cm
i n l e n g t h , and t h e " t e e t h " on t h e s p a c e c r a f t a r e 5 cm a p a r t .
i n c l i n a t i o n o f 50 degrees f r o m t h e s u r f a c e normal.
T h i s view i s taken w i t h a camera
Flg. (AFTER) Venera 14 panorama t r a n s f o r m e d i n t o V i k i n g l a n d e r s u r v e y mode p e r s p e c t i v e ; see t e x t f o r
details.
O Lunar and Planetary Institute
Provided by the NASA Astrophysics Data System