# Enhancing Meteor Observations with Photodiode Detectors
## 3 Concept
Voltages from each module are sampled at 2000 Hz in a multiplexed manner, digitized (12-bit) by an ADC, digitally filtered in real time, then decimated to 100 Hz, and finally sent to a computer via RS232. The decision to use four modules in our observation system was based on several key considerations. First and foremost, the use of four independent modules allowed us to carefully examine the nature of the observed signals and distinguish between authentic signals coming from the sky and the noise generated by the sensors themselves. If all four modules record almost identical correlations during observations, the influence of the sensor's own noise can be considered minimal or even negligible, since this noise, being an independent phenomenon for individual modules, would not be correlated between the modules. In addition, the use of four modules allows verification that the observed light impulse is not the result of the registration of a high-energy particle, also known as a cosmic ray. This type of event is generally detected by only one of the sensors and would be a source of false detections if only a single module was used. Second, we plan to use three of the four modules for observations with optical filters in different spectral ranges, related to the presence of three main elements in meteors: magnesium, sodium, and calcium [19]. The fourth module will be used for broadband observations without filtering, showing the highest sensitivity to fainter meteors. Moreover, this wide-band signal will be used to confirm or reject phenomena observed in the other wavelengths. This configuration should allow us to analyze the signals in a more complex way and gain a deeper understanding of the observed phenomena. Such experiments are planned for the next years of research activity as the module will be sent to our remote station in Spain. Another argument for using four modules is the specification of the ADuC7020 microcontroller used, which allows the connection of up to four sources of analog signals and perform multiplexed sampling. Thanks to this, we can efficiently and economically manage data from different modules while maximizing the capabilities of our observation unit. Our system is equipped with an ASI ZWO 178 MM camera (Suzhou ZWO Co., Ltd., Suzhou, China) with a 2.5 mm fisheye lens, which allows 360-degree image recording. Taking exposures of 60 s, this camera serves as a verification unit for the meteor light pulses recorded by the photodiode modules. The camera is connected to an Intel NUC computer via a USB interface and operated with use of Python (version 3.8) script incorporating ASI ZWO libraries. The images from the camera and the data transferred from photodiode modules are received and synchronized by Python script running on Intel NUC to keep maximal correlation of both data types. The entire system, including the photodiode modules, camera, all electronics, and Intel NUC, was housed in a specially constructed box. This box is equipped with a system for ventilating and heating the components to prevent dew from settling on the components. It also has a large window made of BK-7 glass, allowing light to reach both the photodiodes and the camera. The small housings for the individual diode modules have also windows (BK-7 glass) of about 20 mm \(\times\) 20 mm through, which light can reach a photodiode. All four modules and the camera are placed horizontally, with the camera and photodiodes directed to the zenith. The system with the main elements extracted from the housing and opened to reveal the interiors is presented in Figure 2.