Fotogrametrik ve fotogrametrik olmayan ölçmelerin birarada dengelenmesi ile en uygun durumun araştırılması

Abstract

Son yıllarda bilgisayar tekniğinin hızla gelişmesi sonucu, fotogrametrik değerlendirmelerde ortaya çıkan matematiksel problemlerin sayısal çözüm olanaklarının hızla artması sonucu, analitik fotogrametri yöntemleri de ge lişmiştir. Bu çalışmanın ilk bölümünde f otogrametrik nokta belirlemesinde, ışın demetleri ile dengeleme prob leminde, fotogrametrik ve fotogrametrik olmayan ölçmele rin birarada dengelenmesinin kullanım alanları ve diğer yöntemlere göre üstünlükleri üzerinde durulmuştur. İkinci bölümde, hava triyangülasyonunun amacı ve gelişimi anlatılarak, hava triyangülayonunda kullanılan blok denge lemesi yöntemleri açıklanmıştır. üçüncü bölümde, fotogrametrik ve fotogrametrik olmayan ölçmelerin birbirleri ile olan ilişkilerini sağlayacak bağıntıların kurulmasını esas alan matematik model açık lanmıştır. Matematik modelin kurulması sırasında, ölçme ler iki ayrı grupta ele alınmıştır. Birinci grupta, fo togrametrik olmayan ölçmeler olarak, ölçülen boylar, ya tay açılar, yükseklik farkları ve yükseklikler için dü zeltme denklemleri kurulmuştur. İkinci grupta ise foto grametrik ölçmeler olarak, resim koordinatları, cisim koordinatları ve dış yöneltme parametreleri için düzeltme denklemleri kurulmuştur. Fotogrametrik ve fotogrametrik olmayan ölçmeler için kurulan düzeltme denklemleri bir- araya getirilerek, elde edilen denklem sisteminin, en küçük kareler yöntemine göre Çözümü açıklanarak, uygu lamada kullanılan bilgisayar programı ve özellikleri an latılmıştır. Çalışmanın uygulama bölümü olan dördüncü bölümde, hava fotogrametrisi ve yersel fotogrametriye ait dört ayrı ve ri grubu ile, fotogrametrik ve fotogrametrik olmayan öçl- melerin birarada dengelenmesi işlemi uygulanarak, sonu- lar irdelenmiştir. Beşinci bölümde, uygulama bölümünde elde edilen sonuçlara göre dengeleme hesabına kapsatılan jeodezik ölçmelerin, hesaplanan nokta koordinatlarına olan etkileri belirlenmiştir.

Photogrammetry is defined as " The art and science of obtaining reliable measurements by means of photography." New photogrammetric methods and instrumentation developed in recent years can help to solve problems in many photogrametric applications. The most striking feature of the new technique is that photogrammetric bundles replace photogrammetric stereo models. From the beginning each stereo model had sufficient geodetic control points for the restitution of the model. Later on techniques were developed to use less geodetic control because of the cost and labor for each geodetic point. For this photogrammetric triangulation methods were developed. Photogrammetric triangulation methods comprise two steps. The geodetic triangulation and leveling network are measured and adjusted separately from the photogrammetric measurements. The points determined are used as control for the following photogrammetric adjustment. That control is supposed to be without errors and the point coordinates are often considered to be uncorrelated. In many research projects and also in many practical applications these assumptions have proved to be wrong. There have been tensions and errors in control net which have been discovered in the photogrammetric adjustment. This has been more clearly demonstrated recently due to the increase in accuracy of the photogrammetric point determination. A way of obtaining better control of these discrepancies is to transfer variance - covariance information stating the quality and correlation of the control points. However, this method is hard to implement since the geodetic control often belongs to different nets, measured at different times. vi In case the geodetic net is established at the same time as the photogrammetric block triangulation is done, there is a better way to solve the problem of transferring variance -covarince information in the adjustment. The solution is to adjust the geodetic and photogrammetric observations simultaneously. The aim of the this study is examine to effects of geodetic observations on object coordinates by means of test data results which are obtained by simultaneously adjustment geodetic and photogrammetric observations. In the second part, block adjustment methods are discussed in details. The formulation of a mathematical model for simultaneously adjustment geodetic and photogrammetric observation involves the following three basic steps; 1- Develop observation equation for each type of observation. (Geodetic and photogrammetric observations. ) 2- Generate all necessary observation equations to build a mathematical model of the photogrammetric problem. 3- Develop an efficient computation algorithm. These steps are illustrated in third section by developing a simultaneously solution model for the problem of analytical aerial triangulation. The same mathematical model can be applied, with little or no modifications, to phototriangulation problems, in close- range and terrestrial photogrammetry. The model can also be easily adopted for space resection and camera calibration. A simultaneous adjustment of all the measurements in a photogrammetric mapping problem can be formulated by the use of condition and observation equations. In the case of analytical aerotriangulation, the basic measurements include; 1- the photo-coordinates of the relevant image points on the photographs, 2- the ground coordinates of at least three control points, Vll auxiliary data on the exterior orientation of the photographs. The purpose of the least squares adjustment is then to determine the most probable solution for the ground coordinates of all the unknown points and the exterior orientation parameters of all photographs. In order to combine photogrammetric and geodetic measurements in a simultaneous adjustment, all the observation equation must be expressed in the same reference coordinate system. Rectangular coordinates have been traditionally used in analytical photogrammetry to express the relationship between the exposure station, the orientation of the optical axis and the position of the ground points. Observation equations for geodetic measurements include three observations derived for measured distances, measured angles and measured elevation differences. These are ; Vs+Gs.Ag-Ls Equations for measured straight line distances,