110° W

12°

11°

10°

9°

8°

12°

11°

10°

9°

8°

105° W 106° W

108° W 107° W 109° W

110° W 106° W 105°W

109° W 108° W 107° W

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

120°

120° 60°

60°

0°

30°

65°

180° 135° 90° 45° 0°

–30°

–65°

0°

30°

65°

–30°

–65°

12.5°

250° E

12°

11°

10°

9°

8°

7.5°

12.5°

12°

11°

10°

9°

8°

7.5°

255° E

254° E 253° E 251° E 252° E

250° E

255°E

253° E 254° E 251° E 252° E

2000

6000

10,000

13,000

16,000

17,000

15,000

11,000

9000

4000

6000

8000

ASCRAEUS

MONS

Ascraeus

Chasmata

A

s

c

r

a

e

u

s

S u

l c

i

Ascraeus

Mensa

The following is a list of image pairs used to produce the 

topographic information for this map. Numbers below correspond to the numbers on the diagram above. Shaded area 

indicates MOLA data.

 ID IMAGE PAIR ID IMAGE PAIR

 1 090A42/055A22 23 210A56/210A08

 2 090A42/055A23 24 210A57/210A07

 3 090A43/055A23 25 210A57/210A09

 4 090A44/055A22 26 210A58/210A08

 5 090A44/055A23 27 210A58/210A10

 6 090A45/055A23 28 210A59/210A09

 7 090A45/055A25 29 210A59/210A11

 8 090A46/055A23 30 210A60/210A10

 9 090A46/055A25 31 210A60/210A12

 10 090A48/055A24 32 210A61/210A11

 11 090A48/055A25 33 210A63/210A13

 12 090A50/055A25 34 892A07/643A49

 13 210A02/210A52 35 892A09/643A76

 14 210A04/210A52 36 892A09/643A78

 15 210A04/210A54 37 892A11/643A75

 16 210A06/210A54 38 892A27/643A51

 17 210A06/210A56 39 892A28/643A49

 18 210A12/210A62 40 892A28/643A51

 19 210A53/210A03 41 892A29/643A51

 20 210A53/210A05 42 892A30/643A78

 21 210A55/210A05 43 892A31/643A78

 22 210A55/210A07 44 892A32/643A78

MTM 10/252E QUADRANGLE VIKING STEREOMODEL COVERAGE

SCALE 1:502 000 (1 mm = 502 m) AT 250° E. (110° W.) LONGITUDE

TRANSVERSE MERCATOR PROJECTION

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 10/252E OMKT: Abbreviation for Mars Transverse Mercator; 

1:500,000 series; center of sheet latitude 10° N., longitude 252.5° E. in 

planetocentric coordinate system (this corresponds to 10/107; latitude 10° 

N., longitude 107.5° 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 3396.0 km and a polar 

radius of 3376.8 km (Kirk and others, 2000). 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 sheet the central meridian is at 250° E. 

(110° 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 as allowed by IAU/IAG 

standards (Seidelmann and others, 2002) and in accordance with current NASA and 

USGS standards (Duxbury and others, 2002). A secondary grid (printed in 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 mapping 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 the stereomodels, 

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 

32 m to 80 m, with a mean of 49 m. Elevation (in meters) is given with respect to 

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

of the DTM values at the MOLA point locations shows that the DTM is on average 

0.6 m lower than the MOLA points (n=242,913; μ=-0.6 m; σ=22 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 the 

DTM is 600 m; features that are less than 600 m in size will not be resolved and features that are smaller than 1800 m in size 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 090, 055, 

892, 643, and 210. 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.

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, Ottawa, Canada, 2002, Commission IV, Working Group 9—Extraterrestrial Mapping, 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., Grecu, A., 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, 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 Becker, K.J., 1997, ISIS—A software architecture for processing 

planetary images (abs.), in Lunar and Planetary Science Conference XXVIII: 

Houston, Lunar and Planetary Institute, p. 1443.

QUADRANGLE LOCATION

Photomosaic showing location of map area. An outline of 

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

42

22

36

34 39

41 43

37

5

8

38

40

24

18

21

11

33

16

15

3

2

23

12

27

17

25

31 10

6

1

29

35

4

9

7

13

U.S. DEPARTMENT OF THE INTERIOR

U.S. GEOLOGICAL SURVEY

GEOLOGIC INVESTIGATIONS SERIES I–2798

Version 1.0

Prepared for the

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION

NORTH

WEST

SOUTH

EAST

18,000 

17,750 

17,500 

17,250 

17,000 

16,750 

16,500 

16,250 

16,000 

15,750 

15,500 

15,250 

15,000 

14,750 

14,500 

14,250 

14,000 

13,750 

13,500 

13,250 

13,000 

12,750 

12,500 

12,250 

12,000 

11,750 

11,500 

11,250 

11,000 

10,750 

10,500 

10,250 

10,000 

9750

9500 

9250 

9000 

8750 

8500 

8250 

8000 

7750 

7500 

7250 

7000 

6750 

6500 

6250 

6000 

5750 

5500 

5250 

5000 

4750 

4500 

4250 

4000 

3750 

3500 

3250 

3000 

2750 

2500 

2250 

2000 

1750 

1500 

1250

Contour Guide, in meters

Prepared on behalf of the Planetary Geology and Geophysics Program, Solar System Exploration Division, Office of Space Science, 

National Aeronautics and Space Administration.

Manuscript approved for publication June 23, 2003

10 20 30 40 60 80 90 70 100 

KILOMETERS

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

Topographic Map of the Southwest Ascraeus Mons Region of Mars

MTM 500k 10/252E OMKT

By

U.S. Geological Survey

2004

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.

Dimensional calibration may vary between electronic plotters and between X and Y 

directions on the same plotter, and paper may change size due to atmospheric conditions; therefore, scale and proportions may not be true on plots of this map.

Digital files available on World Wide Web at http://geopubs.wr.usgs.gov/i-map/i2798

28

44

26

19

20

32

14

30