THE DIRECT GEOREFERENCING APPLICATION AND PERFORMANCE ANALYSIS OF UAV HELICOPTER IN GCP-FREE AREA

There are many disasters happened because the weather changes extremely in these years. To facilitate applications such as environment detection or monitoring becomes very important. Therefore, the development of rapid low cost systems for collecting near real-time spatial information is very critical. Rapid spatial information collection has become an emerging trend for remote sensing and mapping applications. This study develops a Direct Georeferencing (DG) based Unmanned Aerial Vehicle (UAV) helicopter photogrammetric platform where an Inertial Navigation System (INS)/Global Navigation Satellite System (GNSS) integrated Positioning and Orientation System (POS) system is implemented to provide the DG capability of the platform. The performance verification indicates that the proposed platform can capture aerial images successfully. A flight test is performed to verify the positioning accuracy in DG mode without using Ground Control Points (GCP). The preliminary results illustrate that horizontal DG positioning accuracies in the x and y axes are around 5 meter with 100 meter flight height. The positioning accuracy in the z axis is less than 10 meter. Such accuracy is good for near real-time disaster relief. The DG ready function of proposed platform guarantees mapping and positioning capability even in GCP free environments, which is very important for rapid urgent response for disaster relief. Generally speaking, the data processing time for the DG module, including POS solution generalization, interpolation, Exterior Orientation Parameters (EOP) generation, and feature point measurements, is less than 1 hour.

ON MODULES OVER GROUP RINGS OF LOCALLY SOLUBLE GROUPS WITH RANK RESTRICTIONS ON SOME SYSTEMS OF SUBGROUPS

We consider a DG-module A over a Dedekind domain D. Let G be a group having infinite section p-rank (or infinite 0-rank) such that CG(A) = 1. It is known that if A is not an artinian D-module then for every proper subgroup H, the quotient A/CA(H) is an artinian D-module for every proper subgroup H of infinite section p-rank (or infinite 0-rank respectively). In this paper, it is proved that if G is a locally soluble group, then G is soluble. Some properties of soluble groups of this type are also obtained.

ON BOUNDED ARTINIAN-FINITARY MODULES

Let G be a group, R be a ring and A be an RG-module. We say that A is an Artinian-finitary module overRG if for every element g ∈ G, the factor-module A/CA(g) is an Artinian R-module. The study of these modules was initiated by Wehrfritz. If D is a Dedekind domain and U is an Artinian D-module, then we can associate with U some numerical invariants. If V is the maximal divisible submodule of U, then V is a direct sum of finitely many indecomposable submodules. The number bd(U) of these direct summands is an invariant of U. The composition length bF(U/V) of U/V is another invariant of U. We consider the following special case of Artinian-finitary modules. Let D be a Dedekind domain and G be a group. The DG-module A is said to be bounded Artinian-finitary, if A is Artinian-finitary and there are the numbers bF(A) = b, bd(A) = d ∈ ℕ and a finite subset bσ(A) = τ Spec (D) such that lF(A/CA(g)) ≤ b, ld(A/CA(g)) ≤ d and Ass D(A/CA(g)) ⊆ τ for every element g ∈ G. In the article, the bounded Artinian-finitary modules under some natural restriction are studied.

ARTINIAN MODULES OVER FC-HYPERCENTRAL GROUPS

Artinian modules over a group ring DG, where G is an FC-hypercentral group and D is a Dedekind domain, are studied. In particular, the conditions under which an artinian DG-module is countably generated over D, and when the socular height of A is at most, have been obtained.