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Johnson, A.

Publications and source records attributed to Johnson, A..

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2020

The Mars 2020 lander vision system field test

The Mars 2020 Lander Vision System estimates position relative to a map and provides this information to the spacecraft so that large hazards can be avoided during landing. The LVS is a new mission critical sensor and as such requires extensive validation. A field test conducted in May 2019 was the primary means to prove that the LVS will operate as designed. During this test over 600 independent real-time runs on engineering model LVS hardware and software were executed and clearly showed that it could meet a 40m position estimation requirement over a wide operational envelope. This paper will describe the test approach, operations and results. Specific examples as well as aggregate performance will be discussed along with off-nominal testing and fault recovery.

Montgomery, J.↗
NASA NTRS2020

The Mars 2020 Lander Vision System Field Test

The Mars 2020 Lander Vision System estimates position relative to a map and provides this information to the spacecraft so that large hazards can be avoided during landing. The LVS is a new mission critical sensor and as such requires extensive validation. A field test conducted in May 2019 was the primary means to prove that the LVS will operate as designed. During this test over 600 independent real-time runs on engineering model LVS hardware and software were executed and clearly showed that it could meet a 40m position estimation requirement over a wide operational envelope. This paper will describe the test approach, operations and results. Specific examples as well as aggregate per-formance will be discussed along with off-nominal testing and fault recovery.

Johnson, A.↗
NASA NTRS2004

Localization, Localization, Localization

Localization of the two Mars Exploration Rovers involved three independent approaches to place the landers with respect to the surface of Mars and to refine the location of those points on the surface with the Mars control net: 1) Track the spacecraft through entry, descent, and landing, then refine the final roll stop position by radio tracking and comparison to images taken during descent; 2) Locate features on the horizon imaged by the two rovers and compare them to the MOC and THEMIS VIS images, and the DIMES images on the two MER landers; and 3) 'Check' and refine locations by acquisition of MOC 1.5 meter and 50 cm/pixel images.

Parker, T.↗
NASA NTRS2001

Advances in autonomous systems for space exploration missions

This paper focuses on new and innovative software for remote, autonomous, space systems flight operation, including distributed autonomous systems, flight test results, and implications and directions for future systems.

autonomy core technologies↗
NASA NTRS1999

Precise Image-Based Motion Estimation for Autonomous Small Body Exploration

Because they hold answers to questions about the origin of our solar system, comets and asteroids play a prominent role in NASA's roadmap for solar system exploration. This paper presents an algorithm for autonomous onboard motion estimation that will enable the precision guidance and landing necessary for small body sample return.

precision↗