GEO++算法与GNSS定位理论解析

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"GEO++算法理论依据.pdf" GEO++算法是全球导航卫星系统(Global Navigation Satellite System, GNSS)中的一个重要部分,它涉及到伪距生成和定位理论。伪距是GNSS接收机用来计算用户位置的关键数据,这些数据是通过测量接收机与卫星之间的信号传输时间来获得的。在本章中,作者Marco Pini、Gianluca Falco和Letizia Lo Presti详细介绍了这一过程。 GNSS系统,如GPS、GLONASS、Galileo和BeiDou,通过发射特定频率的无线电信号,提供全球范围内的定位服务。这些信号包含了卫星的位置信息以及发射信号的时间戳。当这些信号到达地球表面的接收机时,接收机测量接收到信号的相位或码相位,从而估算出伪距。伪距是实际距离加上信号传播时的延迟,这个延迟包括了大气折射、接收机内部延迟等影响因素。 1. 伪距生成方式: - 码相位测量:GNSS信号通常携带一种称为伪随机噪声码(PRN)的特殊序列。接收机通过与本地生成的相同PRN码进行相关运算,来确定接收到的信号相对于本地信号的延迟,从而得到伪距。 - 相位测量:更精确的定位方法是利用载波相位,即信号的连续波频率。这需要更复杂的硬件支持,但可以实现厘米级的定位精度。 2. 定位理论: - 三/四维定位:基于伪距的定位方法通常需要至少四个卫星的信号,这是因为在一个三维空间中,需要三个独立的距离来确定一个点的位置,再加上时间信号的延迟用于纠正钟差。 3. 误差修正: - 大气折射误差:大气中的电离层和对流层对信号传播速度有影响,需通过模型修正。 - 接收机和卫星钟差:两者的时间基准可能不完全同步,需要通过算法估计并消除。 - 多路径效应:信号反射导致额外的伪距测量,需要通过多路径抑制技术处理。 4. GEO++算法的贡献: GEO++算法可能包含了一些先进的误差校正技术和优化策略,以提高定位精度和鲁棒性。这可能涉及到对非线性模型的处理、快速的平滑算法、数据关联方法等,以处理快速移动的接收机或者在城市峡谷等复杂环境下的定位问题。 5. 实际应用: GEO++算法的理论和方法广泛应用于各种领域,如自动驾驶、无人机导航、精准农业、地质灾害监测、物联网设备定位等,其中对于实时动态定位(RTK)和精密单点定位(PPP)有显著的提升。 GEO++算法是GNSS定位技术的一个重要组成部分,它通过优化伪距测量和处理方法,提升了定位的准确性和可靠性。深入理解这种算法的理论基础和实施细节,对于开发高效、精确的定位系统具有重要意义。
2014-01-14 上传
Home » Learn more about the DC1100 Air Quality Monitor Learn more about the DC1100 Air Quality Monitor Dylos Corporation's DC1100 Air Quality Monitor is the first monitor on the market that has been developed and tested for consumer use. Up until now, the only particulate air quality monitors available for purchase were the extremely high priced units that were sold to hospitals, laboratories, clean room facilities, etc. The DC1100, on the other hand, was designed expressly to meet the needs of the home or office environment at an affordable price. •True Laser Particle Counter •Counts individual particles •Sizes small and large particles •Immediate response to changing environment •Up to 30 days of stored history data The DC1100 Air Quality Monitor provides you with the necessary information for you to assess whether or not your indoor air is clean. It helps you stay proactive in the health of your family and if used in conjunction with the tips provided, you will be able to make sure that you are doing all that you can to keep the air your family breathes clean. All you need to do is simply plug it in and turn it on. The DC1100 will configure itself to continuously count the airborne particles in your home. The DC1100 will let you know if the steps you are taking to improve your air quality are really working or not. The DC1100 will let the consumer know if an $800 air purifier works any better than a $200 one in their home. This will save the consumer money by taking the guesswork out of improving air quality. To assist the consumer in these efforts the DC1100 stores up to 30 days of air quality history for review.
2023-06-02 上传

class SpiralIterator: def init(self, source, x=810, y=500, length=None): self.source = source self.row = np.shape(self.source)[0] #第一个元素是行数 self.col = np.shape(self.source)[1] #第二个元素是列数 if length: self.length = min(length, np.size(self.source)) else: self.length = np.size(self.source) if x: self.x = x else: self.x = self.row // 2 if y: self.y = y else: self.y = self.col // 2 self.i = self.x self.j = self.y self.iteSize = 0 geo_transform = dsm_data.GetGeoTransform() self.x_origin = geo_transform[0] self.y_origin = geo_transform[3] self.pixel_width = geo_transform[1] self.pixel_height = geo_transform def hasNext(self): return self.iteSize < self.length # 不能取更多值了 def get(self): if self.hasNext(): # 还能再取一个值 # 先记录当前坐标的值 —— 准备返回 i = self.i j = self.j val = self.source[i][j] # 计算下一个值的坐标 relI = self.i - self.x # 相对坐标 relJ = self.j - self.y # 相对坐标 if relJ > 0 and abs(relI) < relJ: self.i -= 1 # 上 elif relI < 0 and relJ > relI: self.j -= 1 # 左 elif relJ < 0 and abs(relJ) > relI: self.i += 1 # 下 elif relI >= 0 and relI >= relJ: self.j += 1 # 右 #判断索引是否在矩阵内 x = self.x_origin + (j + 0.5) * self.pixel_width y = self.y_origin + (i + 0.5) * self.pixel_height col = int((x - dsm_data.GetGeoTransform()[0]) / dsm_data.GetGeoTransform()[1]) row = int((y - dsm_data.GetGeoTransform()[3]) / dsm_data.GetGeoTransform()[5]) z = val self.iteSize += 1 return x, y, z, row, col dsm_path = 'C:\sanwei\jianmo\Productions\Production_2\Production_2_DSM_part_2_2.tif' dsm_data = gdal.Open(dsm_path) dsm_array = dsm_data.ReadAsArray() spiral_iterator = SpiralIterator(dsm_array,x=810,y=500) while spiral_iterator.hasNext(): x, y, z, row, col = spiral_iterator.get() print(f'Value at ({x},{y}) ({row},{col}):{z}')这段代码怎么改可以当原始航片该位置像素值为 0 值,修改其像素值为 255,当 原始航片该位置像素值为 255 时,说明此点已被占用,则对地面点(X,Y,Z)标记此点位被遮蔽

2023-05-24 上传

from osgeo import gdal import numpy as np class SpiralIterator: def init(self, source, x=810, y=500, length=None): self.source = source self.row = np.shape(self.source)[0]#第一个元素是行数 self.col = np.shape(self.source)[1]#第二个元素是列数 if length: self.length = min(length, np.size(self.source)) else: self.length = np.size(self.source) if x: self.x = x else: self.x = self.row // 2 if y: self.y = y else: self.y = self.col // 2 self.i = self.x self.j = self.y self.iteSize = 0 geo_transform = dsm_data.GetGeoTransform() self.x_origin = geo_transform[0] self.y_origin = geo_transform[3] self.pixel_width = geo_transform[1] self.pixel_height = geo_transform[5] def hasNext(self): return self.iteSize < self.length # 不能取更多值了 def get(self): if self.hasNext(): # 还能再取一个值 # 先记录当前坐标的值 —— 准备返回 i = self.i j = self.j val = self.source[i][j] # 计算下一个值的坐标 relI = self.i - self.x # 相对坐标 relJ = self.j - self.y # 相对坐标 if relJ > 0 and abs(relI) < relJ: self.i -= 1 # 上 elif relI < 0 and relJ > relI: self.j -= 1 # 左 elif relJ < 0 and abs(relJ) > relI: self.i += 1 # 下 elif relI >= 0 and relI >= relJ: self.j += 1 # 右 #判断索引是否在矩阵内 x = self.x_origin + (j + 0.5) * self.pixel_width y = self.y_origin + (i + 0.5) * self.pixel_height z = val self.iteSize += 1 return x, y, z dsm_path = 'C:\sanwei\jianmo\Productions\Production_2\Production_2_DSM_part_2_2.tif' dsm_data = gdal.Open(dsm_path) dsm_array = dsm_data.ReadAsArray() spiral_iterator = SpiralIterator(dsm_array,x=810,y=500) while spiral_iterator.hasNext(): x, y, z = spiral_iterator.get() print(f'Value at ({x},{y}):{z}')这段代码怎么改可以)依据共线方程将地面点(X,Y,Z)反算其在原始航 片中的像素值行列号( r,c),当 img1 该位置像素值为 0 值,修改其像素值为 255,当 img1 该( r,c) 位置像素值为 255 时,说明此点已被占用,则对地面点(X,Y,Z)标记此点位被遮蔽。

2023-05-25 上传