MIGHT BE DUPLICATE: Pre-Flight Calibration of the Mars 2020 Rover Mastcam Zoom (Mastcam-Z) Multispectral, Stereoscopic Imager
Abstract The NASA Perseverance rover Mast Camera Zoom (Mastcam-Z) system is a pair of zoomable, focusable, multi-spectral, and color charge-coupled device (CCD) cameras mounted on top of a 1.7 m Remote Sensing Mast, along with associated electronics and two calibration targets. The ca...
| Main Authors: | , , , , , , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Springer Netherlands
2021
|
| Online Access: | https://hdl.handle.net/1721.1/132062 |
| _version_ | 1826204915316293632 |
|---|---|
| author | Hayes, Alexander G Corlies, P. Tate, C. Barrington, M. Bell, J. F Maki, J. N Caplinger, M. Ravine, M. Kinch, K. M Herkenhoff, K. Horgan, B. Johnson, J. Lemmon, M. Paar, G. Rice, M. S Jensen, E. Kubacki, T. M |
| author_facet | Hayes, Alexander G Corlies, P. Tate, C. Barrington, M. Bell, J. F Maki, J. N Caplinger, M. Ravine, M. Kinch, K. M Herkenhoff, K. Horgan, B. Johnson, J. Lemmon, M. Paar, G. Rice, M. S Jensen, E. Kubacki, T. M |
| author_sort | Hayes, Alexander G |
| collection | MIT |
| description | Abstract
The NASA Perseverance rover Mast Camera Zoom (Mastcam-Z) system is a pair of zoomable, focusable, multi-spectral, and color charge-coupled device (CCD) cameras mounted on top of a 1.7 m Remote Sensing Mast, along with associated electronics and two calibration targets. The cameras contain identical optical assemblies that can range in focal length from 26 mm (
25.5
∘
×
19.1
∘
FOV
$25.5^{\circ }\, \times 19.1^{\circ }\ \mathrm{FOV}$
) to 110 mm (
6.2
∘
×
4.2
∘
FOV
$6.2^{\circ } \, \times 4.2^{\circ }\ \mathrm{FOV}$
) and will acquire data at pixel scales of 148-540 μm at a range of 2 m and 7.4-27 cm at 1 km. The cameras are mounted on the rover’s mast with a stereo baseline of
24.3
±
0.1
$24.3\pm 0.1$
cm and a toe-in angle of
1.17
±
0.03
∘
$1.17\pm 0.03^{\circ }$
(per camera). Each camera uses a Kodak KAI-2020 CCD with
1600
×
1200
$1600\times 1200$
active pixels and an 8 position filter wheel that contains an IR-cutoff filter for color imaging through the detectors’ Bayer-pattern filters, a neutral density (ND) solar filter for imaging the sun, and 6 narrow-band geology filters (16 total filters). An associated Digital Electronics Assembly provides command data interfaces to the rover, 11-to-8 bit companding, and JPEG compression capabilities. Herein, we describe pre-flight calibration of the Mastcam-Z instrument and characterize its radiometric and geometric behavior. Between April 26
t
h
$^{th}$
and May 9
t
h
$^{th}$
, 2019, ∼45,000 images were acquired during stand-alone calibration at Malin Space Science Systems (MSSS) in San Diego, CA. Additional data were acquired during Assembly Test and Launch Operations (ATLO) at the Jet Propulsion Laboratory and Kennedy Space Center. Results of the radiometric calibration validate a 5% absolute radiometric accuracy when using camera state parameters investigated during testing. When observing using camera state parameters not interrogated during calibration (e.g., non-canonical zoom positions), we conservatively estimate the absolute uncertainty to be
<
10
%
$<10\%$
. Image quality, measured via the amplitude of the Modulation Transfer Function (MTF) at Nyquist sampling (0.35 line pairs per pixel), shows
MTF
Nyquist
=
0.26
−
0.50
$\mathrm{MTF}_{\mathit{Nyquist}}=0.26-0.50$
across all zoom, focus, and filter positions, exceeding the
>
0.2
$>0.2$
design requirement. We discuss lessons learned from calibration and suggest tactical strategies that will optimize the quality of science data acquired during operation at Mars. While most results matched expectations, some surprises were discovered, such as a strong wavelength and temperature dependence on the radiometric coefficients and a scene-dependent dynamic component to the zero-exposure bias frames. Calibration results and derived accuracies were validated using a Geoboard target consisting of well-characterized geologic samples. |
| first_indexed | 2024-09-23T13:03:23Z |
| format | Article |
| id | mit-1721.1/132062 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T13:03:23Z |
| publishDate | 2021 |
| publisher | Springer Netherlands |
| record_format | dspace |
| spelling | mit-1721.1/1320622021-09-21T03:32:08Z MIGHT BE DUPLICATE: Pre-Flight Calibration of the Mars 2020 Rover Mastcam Zoom (Mastcam-Z) Multispectral, Stereoscopic Imager Hayes, Alexander G Corlies, P. Tate, C. Barrington, M. Bell, J. F Maki, J. N Caplinger, M. Ravine, M. Kinch, K. M Herkenhoff, K. Horgan, B. Johnson, J. Lemmon, M. Paar, G. Rice, M. S Jensen, E. Kubacki, T. M Abstract The NASA Perseverance rover Mast Camera Zoom (Mastcam-Z) system is a pair of zoomable, focusable, multi-spectral, and color charge-coupled device (CCD) cameras mounted on top of a 1.7 m Remote Sensing Mast, along with associated electronics and two calibration targets. The cameras contain identical optical assemblies that can range in focal length from 26 mm ( 25.5 ∘ × 19.1 ∘ FOV $25.5^{\circ }\, \times 19.1^{\circ }\ \mathrm{FOV}$ ) to 110 mm ( 6.2 ∘ × 4.2 ∘ FOV $6.2^{\circ } \, \times 4.2^{\circ }\ \mathrm{FOV}$ ) and will acquire data at pixel scales of 148-540 μm at a range of 2 m and 7.4-27 cm at 1 km. The cameras are mounted on the rover’s mast with a stereo baseline of 24.3 ± 0.1 $24.3\pm 0.1$ cm and a toe-in angle of 1.17 ± 0.03 ∘ $1.17\pm 0.03^{\circ }$ (per camera). Each camera uses a Kodak KAI-2020 CCD with 1600 × 1200 $1600\times 1200$ active pixels and an 8 position filter wheel that contains an IR-cutoff filter for color imaging through the detectors’ Bayer-pattern filters, a neutral density (ND) solar filter for imaging the sun, and 6 narrow-band geology filters (16 total filters). An associated Digital Electronics Assembly provides command data interfaces to the rover, 11-to-8 bit companding, and JPEG compression capabilities. Herein, we describe pre-flight calibration of the Mastcam-Z instrument and characterize its radiometric and geometric behavior. Between April 26 t h $^{th}$ and May 9 t h $^{th}$ , 2019, ∼45,000 images were acquired during stand-alone calibration at Malin Space Science Systems (MSSS) in San Diego, CA. Additional data were acquired during Assembly Test and Launch Operations (ATLO) at the Jet Propulsion Laboratory and Kennedy Space Center. Results of the radiometric calibration validate a 5% absolute radiometric accuracy when using camera state parameters investigated during testing. When observing using camera state parameters not interrogated during calibration (e.g., non-canonical zoom positions), we conservatively estimate the absolute uncertainty to be < 10 % $<10\%$ . Image quality, measured via the amplitude of the Modulation Transfer Function (MTF) at Nyquist sampling (0.35 line pairs per pixel), shows MTF Nyquist = 0.26 − 0.50 $\mathrm{MTF}_{\mathit{Nyquist}}=0.26-0.50$ across all zoom, focus, and filter positions, exceeding the > 0.2 $>0.2$ design requirement. We discuss lessons learned from calibration and suggest tactical strategies that will optimize the quality of science data acquired during operation at Mars. While most results matched expectations, some surprises were discovered, such as a strong wavelength and temperature dependence on the radiometric coefficients and a scene-dependent dynamic component to the zero-exposure bias frames. Calibration results and derived accuracies were validated using a Geoboard target consisting of well-characterized geologic samples. 2021-09-20T17:41:44Z 2021-09-20T17:41:44Z 2021-02-18 2021-03-21T04:38:43Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/132062 Space Science Reviews. 2021 Feb 18;217(2):29 PUBLISHER_CC en https://doi.org/10.1007/s11214-021-00795-x Creative Commons Attribution https://creativecommons.org/licenses/by/4.0/ The Author(s) application/pdf Springer Netherlands Springer Netherlands |
| spellingShingle | Hayes, Alexander G Corlies, P. Tate, C. Barrington, M. Bell, J. F Maki, J. N Caplinger, M. Ravine, M. Kinch, K. M Herkenhoff, K. Horgan, B. Johnson, J. Lemmon, M. Paar, G. Rice, M. S Jensen, E. Kubacki, T. M MIGHT BE DUPLICATE: Pre-Flight Calibration of the Mars 2020 Rover Mastcam Zoom (Mastcam-Z) Multispectral, Stereoscopic Imager |
| title | MIGHT BE DUPLICATE: Pre-Flight Calibration of the Mars 2020 Rover Mastcam Zoom (Mastcam-Z) Multispectral, Stereoscopic Imager |
| title_full | MIGHT BE DUPLICATE: Pre-Flight Calibration of the Mars 2020 Rover Mastcam Zoom (Mastcam-Z) Multispectral, Stereoscopic Imager |
| title_fullStr | MIGHT BE DUPLICATE: Pre-Flight Calibration of the Mars 2020 Rover Mastcam Zoom (Mastcam-Z) Multispectral, Stereoscopic Imager |
| title_full_unstemmed | MIGHT BE DUPLICATE: Pre-Flight Calibration of the Mars 2020 Rover Mastcam Zoom (Mastcam-Z) Multispectral, Stereoscopic Imager |
| title_short | MIGHT BE DUPLICATE: Pre-Flight Calibration of the Mars 2020 Rover Mastcam Zoom (Mastcam-Z) Multispectral, Stereoscopic Imager |
| title_sort | might be duplicate pre flight calibration of the mars 2020 rover mastcam zoom mastcam z multispectral stereoscopic imager |
| url | https://hdl.handle.net/1721.1/132062 |
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