# Geospatial information

Several different sensors include geospatial information in the dataset metadata describing the location of the sensor at the time of capture.

**Coordinate reference systems**
The Scanalyzer system itself does not have a reliable GPS unit on the sensor box. There are 3 different coordinate systems that occur in the data:

Most common is EPSG:4326 (WGS84) USDA coordinates

Tractor planting & sensor data is in UTM Zone 12

Sensor position information is captured relative to the southeast corner of the Scanalyzer system in meters

EPSG:4326 coordinates for the four corners of the Scanalyzer system (bound by the rails above) are as follows:

**NW**: 33° 04.592' N, -111° 58.505' W**NE**: 33° 04.591' N, -111° 58.487' W**SW**: 33° 04.474' N, -111° 58.505' W**SE**: 33° 04.470' N, -111° 58.485' W

In the trait database, this site is named the "MAC Field Scanner Field" and its bounding polygon is "POLYGON ((-111.9747967 33.0764953 358.682, -111.9747966 33.0745228 358.675, -111.9750963 33.074485715 358.62, -111.9750964 33.0764584 358.638, -111.9747967 33.0764953 358.682))"

**Scanalyzer coordinates**
Finally, the Scanalyzer coordinate system is right-handed - the origin is in the SE corner, X increases going from south to north, and Y increases from east to the west.

In offset meter measurements from the southeast corner of the Scanalyzer system, the extent of possible motion for the sensor box is defined as:

**NW**: (207.3, 22.135, 5.5)**SE**: (3.8, 0, 0)

*Scanalyzer -> EPSG:4326*
1. Calculate the UTM position of known SE corner point 2. Calculate the UTM position of the target point, using SE point as reference 3. Get EPSG:4326 position based on UTM

**MAC coordinates**
Tractor planting data and tractor sensor data will use UTM Zone 12.

*Scanalyzer -> MAC*
Given a Scanalyzer(x,y), the MAC(x,y) in UTM zone 12 is calculated using the linear transformation formula:

Assume `Gx = -Gx'`

, where `Gx'`

is the Scanalyzer X coordinate.

*MAC -> Scanalyzer*

*MAC -> EPSG:4326 USDA*
We do a linear shifting to convert MAC coordinates in to EPSG:4326 USDA

**Sensors with geospatial metadata**

stereoTop

flirIr

co2

cropCircle

PRI

scanner3dTop

NDVI

PS2

SWIR

VNIR

**Available data**
*All listed sensors*

*stereoTop*

cropCircle

*co2Sensor*

*flirIrCamera*

*ndviSensor*

*priSensor*

*SWIR*

**field scanner plots**

There are 864 (54*16) plots in total and the plot layout is described in the plot plan table.

dimension | value |

# rows | 32 |

# rows / plot | 2 |

# plots (2 rows ea) | 864 |

# ranges | 54 |

# columns | 16 |

row width (m) | 0.762 |

plot length (m) | 4 |

row length (m) | 3.5 |

alley length (m) | 0.5 |

The boundary of each plot changes slightly each planting season. The scanalyzer coordinates of each plot are transformed into the (EPSG:4326) USDA coordinates using the equations above.

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