Recognition and classification of patterned ground polygons from remote sensing data Abstract The main objective of this thesis has been to prove the possibility of using object based image analysis classification for identification of the ice-wedge polygons and to find general method for their classification. The thesis contains a comparison of the object based and pixel based classification of the subject. The three classification rulesets for OBIA were developed on three test sites on Mars captured by HiRISE sensor. As a result, the general classification approach is suggested. The manually collected datasets, which are common in geomorphological research, were used as the reference sample. The OBIA classification provided better results in all three cases, whereas the pixel classification was valid in only one case. Another objective has been the automatization of the process of gaining information about morphometric characteristics of the ice-wedge polygons and the subsequent classification of the polygons. Within the scope of the process were developed methods for creating polygonal network and specified parameters of those methods. Several toolboxes for the ArcGIS software were prepared and they are part of the results of the thesis. Keywords: patterned ground, ice-wedge polygons, remote sensing,...

Yardangs are streamlined ridges carved by the action of wind into consolidated yet erodible substrates. The direction of sediment transport is indicated by their elongate shapes and steep sides which redirects most of the sediment transport layer onto adjacent low-lying surfaces, resulting in lower erosion rates on the elevated areas. Despite this simple premise, the rates of erosion and transport as well as the material properties necessary to form yardangs have until now been largely unknown. This study aims to determine how material properties affect yardang dimensions in order to use yardang morphometry to derive the mechanical properties of a surface that has yet to been explored in situ. As a terrestrial analog for planetary yardangs, we use ignimbrite samples and a Digital Terrain Model (DTM) derived from drone imagery of the Campo Piedra Pomez, Argentina. For comparison, we examine a martian analog using a DTM generated by the HiRISE instrument team for a section of the Medusae Fossae Formation northeast of Aeolis Dorsa. We use the DTMs along with thin sections, porosity, density, and strength measurements of yardang materials to understand the conditions contributing to yardang morphology. This method reveals microscopic evidence of nuanced differences in terrestrial ignimbrite depositional processes that create strong, lightweight, yardang-forming ignimbrite like that suggested to occur in the Medusae Fossae Formation. On average, the CPP ignimbrite samples have 49.51 ± 0.43 percent porosity, density of 1.26 ± 0.13 g/cm^3, and uniaxial compressive strength of 4.88 ± 2.86 MPa. Using the topographic structure of yardangs in the DTMs, we automatically extract yardang polygons and characterize their length, width, height, and spacing in four directions. We ratio these measurements and find that yardang width over minimum crosswind spacing has a geometric mean near one for 4102 terrestrial yardangs (~0.7) as well as for 1269 martian yardangs (~1.3). The ratio of ~1 for closely spaced yardangs is probably caused by increased windspeeds enhancing erosion in the gaps between yardangs until the gaps achieve the same cross-sectional area as the yardangs. Finally, we use regressions of the material properties and morphometry data to suggest that if formation conditions are the same as in the Campo Piedra Pomez, the Medusae Fossae Formation surface would have 52.04 + 1.41 / - 1.37 percent porosity, density of 1.19 ± 0.02 g/cm^3 and strength of 0.64 + 0.84 / -0.36 MPa. These results indicate that topography, porosity, strength, and density attenuate the formation processes that ultimately determine the morphometric properties of yardangs. This establishes a framework on which to make progress towards a quantitative understanding of yardang morphology and evolution. The ArcGIS toolboxes and Python scripts used to obtain our results are available at https://github.com/dmcdoug/yardangtools.

The aim of this thesis is to analyze zonality of the thermal contraction crack polygons on the surface of Mars. Their morphology and its variation are analyzed in relation to the latitude of Mars. For spatial and morphological analysis were selected 64 images from the HiRISE (Mars Reconnaissance Orbiter) polychromatic camera dataset, images are covering the bandwidths proportionally. Images were first visually analyzed using HiView. 258 areas containing the thermal contraction crack polygons (with total area of 1184 km2 ) and 1036 well developed thermal contraction crack polygons were further vectorized using ArcMap. The thermal contraction crack polygons were found in every searched latitude which proves the ubiquity of permafrost. The largest amount of the thermal contraction crack polygons have been found in latitudes ±60ř and 45ř. In these latitudes were also found the largest and probably the deepest thermal contraction crack polygons (average length ranges from 42,1 - 73,6 m). The smallest polygons (average length 7,7 m) were found around the equator. "Altitude" has no effect on the spread of the thermal contraction crack polygons on Mars; however it has the effect on its morphology. The most widespread are pentagonal polygons, which occur mainly in the southern hemisphere. The next most...