75°W

74°W

73°W 72°W 71°W 70°W

75°W

74°W

73°W 72°W 71°W 70°W

18°

18°

19°

20°

21°

22°

19°

20°

21°

22°

285°E

22.5°

286°E

287°E 288°E 289°E 290°E

285°E

286°E

287°E 288°E 289°E 290°E

17.5°

18°

19°

20°

21°

22°

22.5°

17.5°

18°

19°

20°

21°

22°

–1000

–2000

1000

0

–1000

–1000

–2000

–1000

0

–2000

–1000

–1000

0

0

0

–1000

–2000

–1000

0

–1000

0

Sacra 

Fos

sae

Sacra

Dorsa

Nilus 

Mensae

Sacra

Sulci

LUNAE

PLANUM

KASEI

VAL

LES

Photogrammetry by M.R. Rosiek

Map compilation by M.R. Rosiek and B.L. Redding

Digital terrain model review by B.L. Redding and D.M. Galuszka

Nomenclature by J.S. Blue

Editing by J.L. Zigler

Cartography by D.A. Ryan

Manuscript approved for publication November 23, 2004

Prepared on behalf of the Planetary Geology and Geophysics 

Program, Solar System Exploration Division, Office of Space 

Science, National Aeronautics and Space Administration.

SCIENTIFIC INVESTIGATIONS MAP 2866

MC–17

MC–2

MC–3

MC–4

MC–8 MC–9 MC–10 MC–11

MC–1

MC–16 MC–18 MC–19

MC–24

MC–25

MC–26

MC–30

QUADRANGLE LOCATION

Photomosaic showing location of map area. An outline of 

1:5,000,000-scale quadrangles is provided for reference

240°

240° 300°

300°

0°

30°

65°

180° 225° 270° 315° 0°

–30°

–65°

0°

30°

65°

–30°

–65°

1000

750

500 

250 

0 

–250 

–500 

–750 

–1000 

–1250 

–1500 

–1750 

–2000 

–2250 

–2500 

–2750 

–3000

NOTES ON BASE

This map, compiled photogrammetrically from Viking Orbiter stereo image 

pairs, is part of a series of topographic maps of areas of special scientific 

interest on Mars.

MTM 500k 20/287E OMKT

The map code identifies the Mars topographic maps:

MTM 500k 20/287E OMKT: Mars transverse Mercator projection 

(MTM); 1:500,000 series; center of sheet lat 20° N., long 287.5° E. in 

planetocentric coordinate system (this corresponds to 20/072; lat 20° N., 

long 72.5° W. in planetographic coordinate system); orthophotomosaic 

(OM) with color-coded (K) topographic contours and nomenclature (T) 

(Greeley and Batson, 1990)

ADOPTED FIGURE

The figure of Mars used for the computation of the map projection is an oblate 

spheroid (flattening of 1/176.875) with an equatorial radius of 3,396.19 km 

and a polar radius of 3,376.2 km (Seidelmann and others, 2002). The datum 

(the 0-km contour line) for elevations is defined as the equipotential surface 

(gravitational plus rotational) whose average value at the equator is equal to 

the mean radius as determined by Mars Orbiter Laser Altimeter (MOLA; 

Smith and others, 2001).

PROJECTION

The projection is part of a Mars transverse Mercator (MTM) system with 20°-

wide zones. For the area covered by this map, the central meridian is at 290°

E. (70° W.). The scale factor at the central meridian of the zone containing 

this quadrangle is 0.9960 relative to a nominal scale of 1:500,000.

COORDINATE SYSTEM

Longitude increases to the east and latitude is planetocentric (black) as allowed 

by International Astronomical Union/International Association of Geodesy 

(IAU/IAG) standards (Seidelmann and others, 2002) and in accordance with 

current National Aeronautics and Space Administration (NASA) and U.S. 

Geological Survey (USGS) standards (Duxbury and others, 2002). A secondary grid (red) has been added to the map as a reference to the west longitude/planetographic latitude system that is also allowed by IAU/IAG standards 

(Seidelmann and others, 2002) and has been used for previous Mars maps.

CONTROL

Horizontal and vertical control was established using the Mosaicked Digital 

Image Model 2.0 (MDIM 2.0; Kirk and others, 2000) and MOLA data. A portion of MDIM 2.0 covering the map area was extracted in simple cylindrical 

projection. This MDIM image was georeferenced to the MOLA data with an 

affine transformation. The MDIM image and georeferencing information were 

imported into a digital photogrammetric workstation (Miller and Walker, 

1993) and used as an orthophoto to provide horizontal control to stereopairs of 

Viking imagery. The horizontal information was used to extract vertical control from the MOLA data. Note that the distribution of Viking Orbiter images 

suitable for mapping at a scale of 1:500,000 is uneven. Areas mapped in this 

series are chosen, often in blocks of two or more adjacent quadrangles, based 

on scientific interest as well as on the availability of suitable data for accurate 

mapping.

CONTOURS

Contours were derived from a digital terrain model (DTM) compiled on a digital photogrammetric workstation using Viking Orbiter stereo image pairs 

with orientation parameters derived from an analytic aerotriangulation. Contours were drawn automatically using a commercial geographic information 

system (GIS) software package (Environmental Systems Research Institute, 

1994). For stereomodels based on images from orbits 519 and 555, the local 

expected vertical precision based on image resolutions, parallax-to-height 

ratio (that is, convergence angle), and a matching accuracy of 0.2 pixel ranges 

from 92 m to 121 m with a mean of 104 m. For stereomodels based on images 

from orbit 664, the local expected vertical precision ranges from 17 to 20 m 

with a mean of 18 m. Elevation (in meters) is given with respect to the 

adopted Mars topographic datum (see section named "Adopted Figure"). A 

comparison of the DTM values at the MOLA point locations shows that the 

DTM is on average 12 m higher than the MOLA points (n=2,192,471; μ=12 

m; ¥=98 m). Contour lines were generated automatically using GIS software 

and were not edited. Because the contour lines were not edited, small closed 

contour lines, contour lines that intersect, and contour lines that do not match 

features are present. The post spacing for most of the DTM is 600 m; features 

that are less than 600 m in diameter will not be resolved, and features that are 

smaller than 1,800 m in diameter may only have four elevation measurements 

associated with them. This lack of elevation measurements may result in contour lines that do not adequately represent some features. The purpose of this 

mapping project is to produce the digital orthophoto and DTM. This map provides a graphical representation of the digital products that are available.

IMAGE BASE

The image base for this map employs Viking Orbiter images from orbits 519, 

555, and 664. An orthophotomosaic was created on the digital photogrammetric workstation using the DTM compiled from stereo models. Integrated Software for Imagers and Spectrometers (ISIS; Torson and Becker, 1997) 

provided the software to project the orthophotomosaic into the transverse 

Mercator projection.

NOMENCLATURE

Names on this map are approved by the IAU. For a complete list of IAUapproved names, see the Gazetteer of Planetary Nomenclature at 

http://planetarynames.wr.usgs.gov.

REFERENCES

Duxbury, T.C., Kirk, R.L., Archinal, B.A., and Neumann, G.A., 2002, Mars 

Geodesy/Cartography Working Group Recommendations on Mars 

Cartographic Constants and Coordinate Systems, in Joint International 

Symposium on Geospatial Theory, Processing and Applications, 

Commission IV, Working Group 9—Extraterrestrial Mapping, Ottawa, 

Canada, 2002, Proceedings: Ottawa, Canada, International Society for 

Photogrammetry and Remote Sensing [http://www.isprs.org/commission4 

/proceedings/paper.html].

Environmental Systems Research Institute, 1994, Arc commands: Redlands, 

Calif., Environmental Systems Research Institute, Inc.

Greeley, Ronald, and Batson, R.M., 1990, Planetary mapping: New York, 

Cambridge University Press, p. 261–276.

Kirk, R.L., Lee, E.M., Sucharski, R.M., Richie, J.O., Grecu, A.E., and Castro, 

S.K., 2000, MDIM 2.0—A revised global digital image mosaic of Mars in

Lunar and Planetary Science XXXI: Houston, Lunar and Planetary Institute, abstract 2011 [CD-ROM].

Miller, S.B., and Walker, A.S., 1993, Further developments of Leica Digital 

Photogrammetric Systems by Helava: ACSM/ASPRS Annual Convention 

and Exposition, Technical Papers, American Society for Photogrammetry 

and Remote Sensing, v. 3, p. 256–263.

Seidelmann, P.K. (chair), Abalakin, V.K., Bursa, M., Davies, M.E., De Bergh, 

C., Lieske, J.H., Oberst, J., Simon, J.L., Standish, E.M., Stooke, P., and 

Thomas, P.C., 2002, Report of the IAU/IAG Working Group on Cartographic Coordinates and Rotational Elements of the Planets and Satellites—2000: Celestial Mechanics and Dynamical Astronomy, v. 82, p. 

83–110.

Smith, D.E., Zuber, M.T., Frey, H.V., Garvin, J.B., Head, J.W., Muhleman, 

D.O., Pettengill, G.H., Phillips, R.J., Solomon, S.C., Zwally, H.J., 

Banerdt, W.B., Duxbury, T.C., Golombek, M.P., Lemoine, F.G., Neumann, G.A., Rowlands, D.D., Aharonson, O., Ford, P.G., Ivanov, A.B., 

McGovern, P.J., Abshire, J.B., Afzal, R.S., and Sun, X., 2001, Mars 

Orbiter Laser Altimeter (MOLA)—Experiment summary after the first 

year of global mapping of Mars: Journal of Geophysical Research, v. 106, 

p. 23,689–23,722.

Torson, J.M., and K.J., Becker, 1997, ISIS—A software architecture for processing planetary images [abs.], in Lunar and Planetary Science Conference XXVIII: Houston, Lunar and Planetary Institute, p. 1443.

Topographic Map of Part of the Kasei Valles and Sacra Fossae Regions of Mars

MTM 500k 20/287E OMKT

By

Mark R. Rosiek, Bonnie L. Redding, and Donna M. Galuszka

2005

1

2

3

4

5

6

7

8

9

10

11

12

CONTOUR GUIDE (meters)

10 20 30 40 50 60 80 90 70 100 KILOMETERS

SCALE 1:502 000 (1 mm = 502 m) AT 290° E (70° W) LONGITUDE

TRANSVERSE MERCATOR PROJECTION

CONTOUR INTERVAL 250 METERS

Planetocentric latitude and east longitude coordinate system shown in black.

Planetographic latitude and west longitude coordinate system shown in red.

10

U.S. DEPARTMENT OF THE INTERIOR

U.S. GEOLOGICAL SURVEY

Prepared for the

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION

Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government.

Diagram of map area showing locations of image pairs used to produce the topographic information. Numbers on the diagram correspond to numbered image pairs 

listed below.

 No. IMAGE PAIR No. IMAGE PAIR No. IMAGE PAIR

 1 519A05/555A03 12 664A09/664A54 12 664A13/664A63

 2 519A08/555A03 664A09/664A56 664A14/664A62

 3 519A08/555A06 664A09/664A57 664A14/664A63

 4 519A25/555A04 664A10/664A56 664A14/664A64

 5 519A05/555A01 664A10/664A58 664A14/664A65

 6 519A06/555A04 664A11/664A57 664A15/664A63

 7 519A06/555A01 664A11/664A58 664A15/664A65

 8 519A03/555A01 664A11/664A59 664A16/664A65

 9 519A06/555A02 664A11/664A60 664A16/664A66

 10 519A23/555A02 664A12/664A60 664A16/664A67

 11 519A04/555A02 664A12/664A62 664A17/664A67

 12 664A08/664A54 664A13/664A61

MTM 20/287E QUADRANGLE VIKING STEREOMODEL COVERAGE

EAST

WEST

NORTH

SOUTH