Mars CTX MC30 Controlled Polar Mosaic

Originators

Stuart Robbins

Publisher

USGS Astrogeology Science Center

Publication Date

2020-09-09

Abstract

This product is a cartographically controlled mosaic of Mars Chart (MC) 30, Mare Australe. MC-30 covers approximately 4.7% of Mars's surface, from 65°S through to 90°S latitude, and 360° in longitude. The images come from NASA's Mars Reconnaissance Orbiter's Context Camera (CTX), which has been returning between 5-6 meters per pixel images of Mars since 2008. This product was produced using automated cartographic control network code that was then manually edited. It includes data through the Mars Reconnaissance Orbiter CTX PDS release 48. The control network code incorporated all useable images in that release, and there were roughly 10,000 images that met our quality requirements. Those images cover 95.5% of the surface area of the region, though it is significantly more complete south of approximately 70°N. The mosaic was produced by priority-ordering images in an automated method that emphasized Spring/Autumn images, images with an emission or slew angle closest to 0°, and images with the best pixel scale. The mosaic order was manually edited where severe discontinuities were observed due to seasonal frost or when low signal-to-noise images were emphasized. The mosaic was further cosmetically corrected to produce the appearance of an approximately similarly illuminated product throughout. The final network has 3 million tie points, and 99.77% of them have residuals ≤1 pixel (RMS = 0.255 pixels). Re-smithed spacecraft (SPK) and camera (CK) kernels were produced from the solution, also available on this page. The full polar mosaic was split into 4 quads to help with downloads. See files for download from this link. The use of a free application like "wget" is recommended for downloading. Citation: Robbins et al. (2020), Fully Controlled 6 meters per pixel Mosaic of Mars' South Polar Region, Earth and Space Science, Volume 7, Issue 10, DOI: 10.1029/2019EA001054, URL: https://doi.org/10.1029/2019EA001054 References: Robbins, S., 2020, Mars's Red (575-625 nm) Seasonal Approximate Reflectivity Averaged Over Mars Years 24-28 From Mars Orbiter Camera, Journal of Geophysical Research: Planets, Volume 125, Issue 7, DOI: 10.1029/2019JE006231, URL: https://doi.org/10.1029/2019JE006231

Purpose

Controlled south polar image mosaic for CTX.

Contact and Distribution

Format

Raster Data, Regional Mosaic, Remote-sensing Data

Access Constraints

None

Access Scope

Astropedia, MRCTR

Use Constraints

Please cite authors

Edition

Version

Edition Name

1

Supplemental Information

https://doi.org/10.1029/2019EA001054, https://doi.org/10.1029/2019JE00623

Native Data Set Environment

ISIS v3

Astrogeology Theme

Control Network, Image Processing, Remote Sensing

Mission Names

Mars Reconnaissance Orbiter

Instrument Names

CTX

Online Package Link

https://astrogeology.usgs.gov/search/map/mars_ctx_mc30_controlled_polar_mosaic

External File Size

4 Quads (100+ GB each)

Online File Link

https://planetarymaps.usgs.gov/mosaic/Mars/Mars_MRO_CTX_SPole_Mosaic_Robbins/index.html

Access Instructions

This mosaic is available as tiled into 4 large quads using a positive 16bit bit range. We recommend a GIS application or Image Reader capable of reading very large images needed for viewing images and a SPICE reader for reading SPICE kernel data. Using a free download application like "wget" is recommended. Internally the quads were produced as cloud-optimized GeoTiffs (COGs) which means they are compressed with internal pyramids. Thus these file can be streamed to some GIS applications without download.

Contact Address

2255 N. Gemini Drive

Contact City

Flagstaff

Contact State

AZ

Contact Postal Code

86001

Contact Email

astroweb@usgs.gov

Progress

In Work

Update Frequency

As needed

Logical Consistency

The final network has 3 million tie points, and 99.77% of them have residuals ≤1 pixel (RMS = 0.255 pixels, 1.5m).

Process Description

We developed an efficient, accurate workflow within ISIS3 (USGS's Integrated Software for Imagers and Spectrometers v3), driven by Python scripts, to automate much of the control process to create a fully controlled CTX dataset. We demonstrated the viability of this workflow by initially producing a mosaic of Mare Australe (MC-30), covering south of 65°N, or 4.7% of Mars' surface.

Source Title

Context Camera Investigation on board the Mars Reconnaissance Orbiter

Source Online Linkage

https://pds-imaging.jpl.nasa.gov/portal/mro_mission.html

Source PDS Archive

Mars Reconnaissance Orbiter

Horizontal Positional Accuracy Report

Accurate to Control Net

Geospatial Information

Target

Mars

System

Mars

Minimum Latitude

-90

Maximum Latitude

-65

Minimum Longitude

-180

Maximum Longitude

180

Direct Spatial Reference Method

Raster

Object Type

Grid Cell

Raster Row Count (lines)

501946

Raster Column Count (samples)

501946

Bit Type (8, 16, 32)

16

Quad System

Mars 1:5M

Quad Name

MC-30

Radius A

3396190

Radius C

3396190

Control Net

MOLA

Bands

1

Pixel Resolution (meters/pixel)

6

Scale (pixels/degree)

9879.116

Map Projection Name

Polar Stereographic

Latitude Type

Planetocentric

Longitude Direction

Positive East

Longitude Domain

-180 to 180