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Record W2484427460 · doi:10.11575/prism/3063

New strategies for combining gnss and photogrammetric data

2009· dissertation· en· W2484427460 on OpenAlexaff
Cameron Ellum

Bibliographic record

VenuePRISM (University of Calgary) · 2009
Typedissertation
Languageen
FieldEngineering
TopicSatellite Image Processing and Photogrammetry
Canadian institutionsUniversity of Calgary
Fundersnot available
KeywordsGNSS applicationsPhotogrammetryComputer scienceKalman filterBundle adjustmentKinematicsData processingReal-time computingGeographySystems engineeringComputer visionArtificial intelligenceEngineeringGlobal Positioning SystemTelecommunicationsDatabase

Abstract

fetched live from OpenAlex

The basic concept of integrating GNSS and photogrammetry dates back more than 30 years and for at least the past decade it has been ubiquitous in both aerial and terrestrial mapping. Throughout all its history the basic technique for integrating the two technologies has been the same: GNSS data is post-processed using a Kalman filter yielding positions and these positions are then used as constraining information in a photogrammetric least-squares bundle adjustment. As evidenced by its long and essentially unaltered use the existing strategy works well, nevertheless it has some drawbacks. From a theoretical perspective, the integration is sub-optimal while the information flow is only in the one direction. From an operational perspective, the current approach is unwieldy: (at least) two processing packages are required. The objective of the research contained within this work is to examine new strategies for integrating GNSS and photogrammetric data that alleviate the aforementioned limitations of the current integration strategy. Specifically, two new integration strategies are introduced, implemented, and tested: (1) Inter-processor communication between a kinematic GNSS Kalman filter and a photogrammetric bundle adjustment. (2) A combined least-squares adjustment of both GNSS and photogrammetric observations. The first strategy introduces two-way communication between the GNSS and photogrammetric processors, while the second strategy introduces measurement-level integration within a single processor. The combined adjustment also allows some more flexible GNSS processing options; for instance, a non-fixed base station or the use of observations when there are less than the 4 normally required. Testing of the inter-processor communication strategy showed that it could help GNSS positioning following signal outages, yet this improvement does not necessarily translate into improved photogrammetric mapping accuracy. Testing of the combined adjustment demonstrated how photogrammetric control could replace a fixed GNSS base station, and how use of use of GNSS observations during partial signal blockages (when they would otherwise be discarded) could help bound the mapping and exposure position error growth. The combined adjustment testing also showed that the exposure positions derived from a typical aerial block of imagery have too much noise to substantially improve the GNSS positioning; consequently, mapping accuracy also does not improve.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.

metaresearch head score (Codex)0.002
metaresearch head score (Gemma)0.003
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Simulation or modeling · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: none
Teacher disagreement score0.003
Threshold uncertainty score0.009

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0020.003
Meta-epidemiology (narrow)0.0010.001
Meta-epidemiology (broad)0.0010.001
Bibliometrics0.0020.002
Science and technology studies0.0000.001
Scholarly communication0.0030.004
Open science0.0020.003
Research integrity0.0010.001
Insufficient payload (model declined to judge)0.0030.001

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.019
GPT teacher head0.234
Teacher spread0.215 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designSimulation or modeling
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations1
Published2009
Admission routes1
Has abstractyes

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