Study Onautomatic Measurement Of Layer F2in Ionograms Based On Image Processing

As a part of atmospheric, ionosphere has an obvious feature of electrodynamics.It not only protects the earth from the influence of UV radiation and high energy ions,but also reflects low-frequency signals from the earth which achieves long distancecommunications. On the other hand, waves are refracted and scattered when they passthrough the ionosphere, which has a big influence on radio communicationstechnology with aerospace and other space exploration plans. In a period ofionosphere’s rapid change, ground communication, GPS navigation and satellite arefacing varying degrees of impact, even destruction. Therefore, as an important part ofthe atmosphere in the space environment, studying the ionosphere has a veryimportant significance.Previous ionospheric ionograms were measured by hand, which cannot bemeasured as a high-frequency instrument monitoring in24hours. Large amounts ofdata need to take a lot of manpower and resources. In order to improve interpretationcourier and reduce human consumption, this paper is based on the existent measuringrules and digital image processing technology to explore and design an ionogramsautomatic measuring method.The main work includes:1.Make a detailed description of the relevant knowledge of ionospheric verticalmeasurement and a layered structure characteristics and mathematical meaning ofeach parameter. Summarize the existent automatic interpretation methods to lay afoundation for the design of the algorithm in this period. Raising the importance andsignificance of ionograms automatic interpretation.Make a clear understanding of thegoal of this article and design algorithm flow By combing the existent measuring ruleswith image preprocessing method, make a plan for ionograms preprocessingmethod;2.According to the characteristics of the image, select an appropriate filter toremove the noise and use Otsu method to get a binary image for subsequent processing. According to the ionograms’ structure characteristics, separate Region Efrom Region F. The main trace of Layer F has many breakpoints after the separation.Use image dilation to fix them. Remove multiple reflections of Layer F by usingconnected component labeling and choose the main trace of Layer F. Erode the imageto get the bone of the trace which is composed by a single line of pixels.By analyzingthe position and relationship of each pixel on the trace, judge the endpoint,intermediate point and intersection point. By counting the line of the trace, Wave Oand Wave X are classified and separated finally.3.Extract the feature information on the tracing and get the parameter accordingto ionograms measuring rules.Verify the feasibility of this algorithm by experimentand calculate its accuracy. According to the result of the experiment, analyze themeasurement results and error in some special ionograms.