Earth Remote Sensing with Signals of Opportunity Advisors: Prof. J. L. Garrison Graduate Mentor: Yao-Cheng Lin Members: Keming Zhang, Jordan Cecil, Abdul Alqasir, Su Wang The overall goal of this ongoing project is to successfully capture and analyze signals from Earth-based communication satellites in order to gain a better understanding of various geophysical properties of the world around us. We used the Satellite Encyclopedia to acquire essential information about satellites. GPredict is the software we used to track the locations of the satellites in real time at any point in their orbit. Data collection should occur for a particular satellite during the window of time between its AOS and LOS. For the purpose of getting strong and distinct signals, we went to the roof of Northwestern Parking Garage where we had a higher elevation and minimal interference. We used the power adapter from lab to power the spectrum analyzer using the cars battery. We successfully captured the direct and reflective signal from FM 10 and FM 11. A successfully captured signal has a distinct peak that denotes its relative strength. The peak should be centered around the main downlink channel of the satellite. The Yagi antenna design is used to build both UFO and MUOS antennas. It consists of a long Mast, a reflector, a bended dipole, and multiple dipoles. A spectrum analyzer was fine-tuned to capture the specific signal of interest, avoiding interference from other satellites and our surroundings. Screenshot of Gpredict showing nearby Orbcomm satellites Our setup on the roof of Northwestern parking garage Close-up of spectrum analyzer displaying a successfully received signal This semester, the two sub-teams focused on receiving signals from Orbcomm satellites using antennas, and building operational antennas for two satellite systems, the UFO and MUOS. Orbcomm FM 11 satellite Orbcomm FM 10 satellite center frequencies for satellites from Satellite Encyclopedia Name:`OrbcommMUOSUFO Maker:Orbcomm Commercial US militaryUS DOD Channel details: 12 channels, 137 138 MHz for receive and 148 150 MHz for transmit. Four 5-MHz channels. Center: 260 MHz KHz and 22 5-KHz channels Center: 370 MHz Satellite position: Low orbit Geostationary We used 16dB range and 50 trace average to eliminate the noise and see the signal perspicuously. Figure 2 : sample Yagi antenna The ORBCOMM System is a world-wide, two-way, data communications system. A commercial Quad helix antenna is being used to collect data from the ORBCOMM FM Satellites. Figure 3: sample Orbcomm antenna and The interrelationship of the Orbcomm System elements UFO stands for ultra high frequency follow- on. UFO is a group of 8 geostationary satellites that are each responsible for a different zone. West Lafayette is covered by UFO 5 and UFO 6. The signal is amplified to obtain a reading from the spectrum analyzer. MUOS stands for mobile user objective system. MUOS is the replacement satellite group for UFO MUOS is a group of 5 satellites that are currently in progress to reach their positions. The North American CONUS came online in 2015 and has already reached it position. To collect a signal, the MUOS team uses the same techniques for UFO. Figure 4: Finished UFO antenna Figure 6: Finished MUOS antenna Figure 1: Satellite image courtesy ofMatassa C.K. (2011). Comparing the Capabilities and Performa nce of the Ultra High Frequency Follow-On System with the Mo bile Objective User System. Retrieved from Naval Postgraduate School. John D. Oetting And Tao Jen. The Mobile User Objective Syste m (n.d)