## 1 Introduction  
In 1949, [PERSON] introduced the planetary _Kp_ index, derived from three-hourly \(K\) indices specific to observatories [1]. This planetary geomagnetic \(K\) index assesses geomagnetic activity within three-hourly UTC (Coordinated Universal Time) intervals on a quasi-logarithmic scale from 0 to 9. This geomagnetic _Kp_ index quantifies disturbances in the Earth's magnetic field caused by solar activity [2]. The _Kp_ index is derived from observations of magnetic field variations at specific geomagnetic observatories around the world [1]. These observations are used to calculate a single global index that represents the overall level of geomagnetic activity. The _Kp_ index is particularly useful for assessing the potential impact of space weather events, such as solar flares and coronal mass ejections, on Earth's magnetosphere. Monitoring the _Kp_ index is important for space weather forecasting and for assessing the potential impacts on various technological systems on Earth. The _Kp_ index is then derived by combining the individual _K_-values from different observatories. The overall _Kp_ index is a global measure of geomagnetic activity during a specific three-hour period. Every day the 24 h _Kp_ index is calculated by summing the _Kp_ values over eight consecutive 3 h intervals. The _Kp_ index is calculated on a semi-logarithmic scale, while its counterpart is calculated on a linear scale and is known as the _Ap_ index. The daily sum of the _Ap_ index is calculated by summing the eight three-hour _Ap_ index values. This helps provide a smoother representation of the overall geomagnetic activity for a full day [1]. It provides a daily measure of geomagnetic activity, and its values are related to the disturbance storm time (_Dst_) index, which measures the globally averaged strength of the Earth's geomagnetic field disturbance. The _Dst_ index was proposed by [PERSON] in 1964 [3] to measure the magnitude of the current that produces the axially symmetric disturbance field. It is derived from geomagnetic field variations in the \(H\) component measured at four low-latitude stations. The development of the _Dst_ index was a significant step in understanding and monitoring space weather, as it allowed scientists to assess the impact of solar activity on the Earth's magnetosphere. The _Dst_ index is widely used in space weather research and forecasting to characterize the severity of geomagnetic storms. In the realm of space physics and geomagnetism, numerous indices such as _Kp_, _Ap_, and _Dst_ are employed to assess and quantify the dynamic nature of the Earth's magnetosphere in response to solar activity. However, when delving into the intricacies of local magnetic field variations, particularly those influenced by lunar waves, a more refined approach is necessary. In this context, the focus shifts from general indices averaged over the day to the development of a distinct index for each hour and the specific geographic locations where magnetometers are deployed. This approach aims to capture the complexity of the local magnetic field in real-time, allowing for a more detailed understanding of the interplay between lunar waves and geomagnetic activity at specific locations and temporal intervals. Fine-grained indices of this nature enhance our understanding of the intricate dynamics within the Earth's magnetosphere and its interactions with celestial bodies such as the Moon. Understanding the Earth's magnetic field requires tracing its evolution over time and analyzing spatial variations. In [4], the field history of the Earth is determined through the current polarization of crustal material, specifically clay-like sediments in unconsolidated water environments, offering a simple form of polarization for examination. Ref. [5] enhances our understanding of the Earth system by investigating its internal dynamics and its impact on geospace, employing high-precision measurements of magnetic field characteristics, coupled with navigation, accelerometer, and electric field data.