Sensor to calculate FSPL over time

spatz/sensors/antenna/pathloss.py

@@ -0,0 +1,68 @@
+from numpy.typing import ArrayLike
+from typing import List, AnyStr
+from numpy import matrix
+from typing import List
+import re
+from io import StringIO
+import numpy as np
+
+import pandas as pd
+import math
+
+from scipy import constants as consts
+
+from spatz.sensors import Sensor
+from spatz.simulation import Simulation
+from spatz.transforms import Transform
+from spatz.dataset import Dataset
+from spatz.logger import Logger
+import time
+
+
+
+'''
+
+Estimats the free-space path loss (FSPL) in dB
+https://de.wikipedia.org/wiki/Freiraumd%C3%A4mpfung
+
+Used formulas:
+FSPL = ((4*pi*d*f)/c)^2
+FSPL_db = 20*log10((4*pi*d*f)/c)
+c = sciply.constants.c
+
+
+Parameters:
+ - Frequency: duh
+ - RX antenna offset: offset of the recieving antenna from the launchrail in Launcher frame. (Z is up, Y is north, X is east )
+'''
+
+
+class AntennaPathloss(Sensor):
+    def __init__(self, dataset: Dataset, logger: Logger, transforms: List[Transform] = [], frequency:float = 2.45e9, rx_antenna_offset: ArrayLike = np.array([0,0,0])):
+        super().__init__(dataset, logger, transforms)
+        self.__freq = frequency
+        self.__lambda = self.__freq/consts.c
+        self.__rx_offset = rx_antenna_offset
+
+
+    def _get_data(self) -> ArrayLike | float:
+        #Get rocket position
+        pos_fl = self._dataset.fetch_values(['x','y','z']) # X,Y,Z position in launcher frame. Z is upm, X is east
+
+        #Get connection vector
+        rocket_to_gs_fl = pos_fl - self.__rx_offset
+
+        #Get distance
+        dist = np.linalg.norm(rocket_to_gs_fl)
+        self._log("distance",dist)
+
+        #Calc FSPL
+        FSPL_db = 20.0 * np.log10(np.pi*4*dist*self.__lambda)
+
+        return FSPL_db    
+    
+    def _sensor_specific_effects(self, x: ArrayLike) -> ArrayLike:
+        return x
+    
+    def _get_name(self) -> AnyStr:
+        return 'antenna/pathloss'