Introduction

1. Horizon Detection System The Horizon Detection System utilizes two subsystems: the Thermopile System and the Imaging System. Each system will detect the horizon and send the information to a single board computer to determine the payload’s pitch and roll. The Horizon Detection System is mounted on the ImAP RSD Payload Figure, as shown on the far left. Horizon Detection System Diagram ImAP RSD Payload Thermopile System Imaging System ImAP RSD was created to determine crop health using remotely sensed data and image processing from a high altitude weather balloon. The balloon has an attached payload to capture aerial images at specific GPS locations. The goal for this semester is to design a Horizon Detection System that will capture data from each side of the payload to determine the spatial orientation of the payload. Thermopile Theory of Operation The thermopile system detects the horizon based on the average temperature seen by the horizon facing thermopile and comparing it with the sky and ground temperatures. The average horizon temperature is given by the following equation: The roll of the payload (θroll) can then be determined by the following equation by combining the thermopile system temperatures in the single board computer. Original image The imaging system will detect the horizon based on the images captured from each side of the payload. The image will be processed using blue and grayscale based algorithms. The figures to the right illustrate this process. The blue based algorithm is best when cloud cover is present. The grayscale algorithm works best in the presence of haze. Blue Threshold/ Monochrome Grayscale Imaging System Diagram Thermopile Function Diagram Thermopile System Diagram Edge Detection after Grayscale • Edge Detection after Blue Threshold/ Monochrome Introduction The system block diagram of the image system is shown above. A VGA CCD camera will be connected to an FPGA. All of the processing will be done onboard the FPGA. The FPGA will be interfaced with SDRAM for storage of the images. A VGA port is available for debugging. Final Image after Blue threshold/monochrome Final Image after Grayscale Estimated Resources Testing The test platform, which is shown to the left, is a dual-axis mount that provides a range of motion to simulate different pitch and roll orientations for the HDS. To determine the angle of the platform, we will be using incremental optical rotary encoder. The camera would be placed on one edge of the top board and will be tested by moving the board. The encoder values when compared to the values calculated by the HDS will provide with the degree of accuracy of the system (HDS). Personal Efforts Budget Test Fixture $ 50 VGA Camera board $ 57 Thermopile board $ 80 Student Labor $10/hr $ 7640 ----------------------------------------- Total $ 7827 ONGO – 02a http://seniord.ece.iastate.edu/ongo02a CLIENT FACULTY ADVISOR Dr. John Basart TEAM MEMBERS Usman Aurakzai (EE) Christina McCourt (EE) Chia-Yuan Chang (CPRE) Andy Schulte (EE) Matt Clausman (EE) ShobhitVaish (EE) Jesse Griggs (EE) ACKNOWLEDGEMENT High Altitude Balloon Experiments in Technology (HABET) Team