How to read the contents of a VRI file

By default, the files downloaded from FieldNet are in a .vri file, which is not human readable. These files are zipped, but running a simple command to unzip them will not work. The first byte of the file is not correct for a standard unzipping utility such as the unzip command on a unix system. The file header for a zip file is supposed to be PK\x03\x04, and the file header for the .vri file is RK\x03\x04. To fix this and allow your system to unzip the file, you have to change the first byte. To do this in your terminal (tested on macOS):

echo -ne P | dd conv=notrunc bs=1 count=1 of={your_file_name}.vri

How to create a new VRI file

There are three steps to creating a new VRI file:

Create a plan.geojson file which describes the VRI plan
Zip the plan.geojson file into a .vri file
Switch the file header to match the .vri format

These three steps are discussed in more detail below.

Creating a `plan.geojson` file

Every plan.geojson file must have exactly this naming convention. In addition it must adhere to the standards laid out in https://datatracker.ietf.org/doc/html/rfc7946 . Specifically, the type of GeoJSON document that plan.goejson is is a FeatureCollection. The tables below describe the parts of the GeoJSON format that are relevant to the plan.geojson file, as well as what additional fields are used in the pla.geojson file.

Table 1: `plan.geojson` high level structure

Field	Type	Required	Notes

Field	Type	Required	Notes
“type”	String	yes	Must be exactly “FeatureCollection”
“features”	Array of `features` objects	yes	See table 2 for details
“crs”	Coordinate reference system object	yes	Must be exactly: `{ "type": "name", "properties": { "name": "urn:ogc:def:crs:OGC:1.3:CRS84" } }`
“bbox”	Array of numbers	yes	These points are represent a “bounding box” around which contains all of the coordinates in the “features” array. The order is: [ `furthestEastLongitude`, `furthestSouthLatitude`, `furthestWestLongitude`, `furthestNothLatitude` ]
“properties”	A “global” `properties` object	yes	See table 3 for details

Table 2: `features` JSON object structure

Field	Type	Required	Notes

Field	Type	Required	Notes
“type”	String	yes	Must be exactly “Feature”
“geometry”	GeoJSON geometry object	yes	As far as I can tell, FieldNet only uses `Polygon` geometry objects. See table 4 for details about this object
“properties”	A “local” `properties` JSON object	yes	See table 5 for details

Table 3: Global `properties` JSON object structure

This properties object is being called the “global” properties object because it appears in the top level of the plan.geojson document. Note: this is different than the properties object described in table 5.

Field	Type	Required	Notes

Field	Type	Required	Notes
“plan_type”	Enum	yes	Must be one of “FullVRI”, “VRI_Percent_Based”, or “VRIIgnoreFlowRates”. Generally, we will want to be using the “FullVRI” option.
“max_depth”	Number	yes	If “plan_type” is “FullVRI”, this number represents the maximum depth in millimeters used in this plan. Otherwise, this number represents the maximum depth as a percent of the maximum depth the machine can go to. For example, if “plan_type” were “VRIIgnoreFlowRates”, and “max_depth” was 55, that would represent a maximum depth that is 55% of the machine’s maximum.

Table 4: `Polygon` GeoJSON object structure

Field	Type	Required	Notes

Field	Type	Required	Notes
“type”	String	yes	Must be exactly “Polygon”. While other geometries are supported by the GeoJSON spec, it seems like the FieldNet system only generates “Polygon” geometries.
“coordinates”	Array of arrays of arrays of numbers	yes	Each array of numbers contains exactly two numbers: the first represents the longitude of the point, and the second represents the latitude of the point. These points must be sorted counterclockwise. Additionally, the last point must be identical to the first point. The doubly nested array is a GeoJSON feature, but FieldNet seems to only every have a single array of arrays of numbers within their coordinates array.

Table 5: local `properties` JSON object structure

Field	Type	Required	Notes

Field	Type	Required	Notes
“name”	String	yes	This is the name of the polygon in the UI
“type”	Enum	yes	One of “application”, “avoid”, or “ignore”. ”application”: Apply a certain depth of water to this area. ”avoid”: As soon as a sprinkler hits this zone, it’ll shut off - so bordering zones will be off. The priority is for the avoid zone. ”ignore”: This will prioritize the non-ignore area, as the sprinkler transitions into the ignore it will still pulse to ensure the neighbouring zones get the right depth.
“colour”	Hex string	yes	A string containing the hex code of the colour of the feature.
“application_depth”	Number	yes	The depth in millimeters of the irrigation. This is always provided, even when the plan is provided in percents. When the “type” is “avoid” or “ignore” this is always 0.
“application_percent”	Number	yes	The depth in percent of the maximum depth that the machine can irrigate. This is always provided, however when the plan is a “FullVRI” plan, it has a value of 0.

Example `plan.geojson` document

{
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "properties": {
        "name": "Field 1",
        "colour": "#00A4E6",
        "type": "application",
        "application_depth": 15.24,
        "application_percent": 0
      },
      "geometry": {
        "type": "Polygon",
        "coordinates": [
          [
            [
              -112.43697881698608,
              50.170837555341194
            ],
            [
              -112.4371075630188,
              50.16683798492274
            ],
            [
              -112.43678569793701,
              50.16569715262685
            ],
            [
              -112.43236541748047,
              50.165532210764646
            ],
            [
              -112.42837429046631,
              50.166425639042664
            ],
            [
              -112.42796659469604,
              50.16839112246747
            ],
            [
              -112.43039131164551,
              50.169957953446776
            ],
            [
              -112.43697881698608,
              50.170837555341194
            ]
          ]
        ]
      }
    }
  ],
  "crs": {
    "type": "name",
    "properties": {
      "name": "urn:ogc:def:crs:OGC:1.3:CRS84"
    }
  },
  "properties": {
    "plan_type": "FullVRI",
    "max_depth": 15.24
  },
  "bbox": [
    -112.42796659469604,
    50.165532210764646,
    -112.4371075630188,
    50.170837555341194
  ]
}

Zipping the `plan.geojson` file

To zip the plan.geojson file, you need to use whatever zip utility you prefer, so long as it uses the deflate method to reduce the file size. Additionally, you will need to change the file extension from .zip to .vri

Setting the appropriate file header

To set the appropriate file header for FieldNet to be able to process it, you need to set the first byte to be 0x52. In order to do this on a Unix based terminal, run:

Litefarm

Working with VRI files

How to read the contents of a VRI file

How to create a new VRI file

Creating a `plan.geojson` file

Table 1: `plan.geojson` high level structure

Table 2: `features` JSON object structure

Table 3: Global `properties` JSON object structure

Table 4: `Polygon` GeoJSON object structure

Table 5: local `properties` JSON object structure

Example `plan.geojson` document

Zipping the `plan.geojson` file

Setting the appropriate file header

Working with VRI files

How to read the contents of a VRI file

How to create a new VRI file

Creating a plan.geojson file

Table 1: plan.geojson high level structure

Table 2: features JSON object structure

Table 3: Global properties JSON object structure

Table 4: Polygon GeoJSON object structure

Table 5: local properties JSON object structure

Example plan.geojson document

Zipping the plan.geojson file

Setting the appropriate file header

Creating a `plan.geojson` file

Table 1: `plan.geojson` high level structure

Table 2: `features` JSON object structure

Table 3: Global `properties` JSON object structure

Table 4: `Polygon` GeoJSON object structure

Table 5: local `properties` JSON object structure

Example `plan.geojson` document

Zipping the `plan.geojson` file