Please wait, while we are loading the content...
Please wait, while we are loading the content...
| Content Provider | IEEE Xplore Digital Library |
|---|---|
| Author | Shankar, U.J. Wen-Jong Shyong Criss, T.B. Adams, D. |
| Copyright Year | 2008 |
| Description | Author affiliation: Appl. Phys. Lab., Johns Hopkins Univ., Laurel, MD (Shankar, U.J.; Wen-Jong Shyong; Criss, T.B.; Adams, D.) |
| Abstract | The NASA Autonomous Precision Landing and Hazard Avoidance Technology (ALHAT) program is developing an autonomous precision landing system capable of landing a spacecraft on the moon. To achieve the desired 90 m (3sigma) landing accuracy some version of a Terrain Relative Navigation (TRN) is necessary. One such algorithm is described in a companion paper. These algorithms require an accurate representation of the lunar terrain for both the on-board TRN algorithms and the ground-based software test bed (truth model) to verify the performance of the algorithms. In its terminal landing phase, the spacecraft will touchdown in a safe location using two algorithms: Hazard Detection and Avoidance (HDA) and the Hazard-Reference Navigation (HRN). To verify the performance of the HDA and HRN algorithms, ALHAT needs lunar surface models incorporating rock shape and size distribution statistics. The Johns Hopkins University Applied Physics Laboratory has been tasked by ALHAT to supply lunar terrain data for ALHAT. This includes both terrain data (elevation and surface reflectivity properties) for TRN and rock statistics for HDA and HRN. At the present time, detailed terrain data from satellite measurements is not available for all the lunar regions. In particular, data for the polar regions, which have been identified as regions of high importance, are sparse. Several missions are underway to map the lunar surface. Until data from the laser altimeters and cameras on these spacecraft are available, APL will provide representative lunar terrain data to test the ALHAT algorithms. This paper discusses APL's different approaches to generating lunar digital elevation maps for TRN. It does not discuss the generation of rock statistics for HDA and HRN. |
| Starting Page | 1 |
| Ending Page | 10 |
| File Size | 3741276 |
| Page Count | 10 |
| File Format | |
| ISBN | 9781424414871 |
| ISSN | 1095323X |
| DOI | 10.1109/AERO.2008.4526300 |
| Language | English |
| Publisher | Institute of Electrical and Electronics Engineers, Inc. (IEEE) |
| Publisher Date | 2008-03-01 |
| Publisher Place | USA |
| Access Restriction | Subscribed |
| Rights Holder | Institute of Electrical and Electronics Engineers, Inc. (IEEE) |
| Subject Keyword | Moon Space vehicles Software algorithms Hazards Navigation Statistical distributions NASA Space technology Software performance Software testing |
| Content Type | Text |
| Resource Type | Article |
| Subject | Aerospace Engineering Space and Planetary Science |
National Digital Library of India (NDLI) is a virtual repository of learning resources which is not just a repository with search/browse facilities but provides a host of services for the learner community. It is sponsored and mentored by Ministry of Education, Government of India, through its National Mission on Education through Information and Communication Technology (NMEICT). Filtered and federated searching is employed to facilitate focused searching so that learners can find the right resource with least effort and in minimum time. NDLI provides user group-specific services such as Examination Preparatory for School and College students and job aspirants. Services for Researchers and general learners are also provided. NDLI is designed to hold content of any language and provides interface support for 10 most widely used Indian languages. It is built to provide support for all academic levels including researchers and life-long learners, all disciplines, all popular forms of access devices and differently-abled learners. It is designed to enable people to learn and prepare from best practices from all over the world and to facilitate researchers to perform inter-linked exploration from multiple sources. It is developed, operated and maintained from Indian Institute of Technology Kharagpur.
Learn more about this project from here.
NDLI is a conglomeration of freely available or institutionally contributed or donated or publisher managed contents. Almost all these contents are hosted and accessed from respective sources. The responsibility for authenticity, relevance, completeness, accuracy, reliability and suitability of these contents rests with the respective organization and NDLI has no responsibility or liability for these. Every effort is made to keep the NDLI portal up and running smoothly unless there are some unavoidable technical issues.
Ministry of Education, through its National Mission on Education through Information and Communication Technology (NMEICT), has sponsored and funded the National Digital Library of India (NDLI) project.
| Sl. | Authority | Responsibilities | Communication Details |
|---|---|---|---|
| 1 | Ministry of Education (GoI), Department of Higher Education |
Sanctioning Authority | https://www.education.gov.in/ict-initiatives |
| 2 | Indian Institute of Technology Kharagpur | Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project | https://www.iitkgp.ac.in |
| 3 | National Digital Library of India Office, Indian Institute of Technology Kharagpur | The administrative and infrastructural headquarters of the project | Dr. B. Sutradhar bsutra@ndl.gov.in |
| 4 | Project PI / Joint PI | Principal Investigator and Joint Principal Investigators of the project |
Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon |
| 5 | Website/Portal (Helpdesk) | Queries regarding NDLI and its services | support@ndl.gov.in |
| 6 | Contents and Copyright Issues | Queries related to content curation and copyright issues | content@ndl.gov.in |
| 7 | National Digital Library of India Club (NDLI Club) | Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach | clubsupport@ndl.gov.in |
| 8 | Digital Preservation Centre (DPC) | Assistance with digitizing and archiving copyright-free printed books | dpc@ndl.gov.in |
| 9 | IDR Setup or Support | Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops | idr@ndl.gov.in |
|
Loading...
|