4P and 4P+ Detailed Introduction

Each of our sensor systems includes a fully self-contained navigation system driven by integrated GPS, inertial measurement unit (“IMU”), and Extended Kalman Filter (“EKF”) analytics solution to enable positioning measurements with no need for aircraft data. The self-contained navigation system enables image triggering without the need for external sources or data cabling.

 Information value is created through an engineered balance of spatial and spectral resolution with spectral diversity. The 4P Series’ narrow spectral bands isolate key markers of evolving plant health conditions while delivering true-color RGB for the ever-important value of human visual context.

This document introduces the factors related to mission planning and data collection that can affect system performance and provides guidance on best practices for obtaining reliable high-quality results. Remember to check your region's drone flight regulations!

Unboxing

4P and 4P+ Field Sensor 

AIS, data cable, microSD card

As a general rule, insert a memory card into the sensor and connect your AIS (Ambient Illumination Sensor) to the 4P before startup, and do not disconnect either until after the shutdown. The white connector on the data cable plugs into the field sensor, and the black connector plugs into the AIS. The system will boot up as soon as power is connected to the field sensor.

Mounting 

Please reference these instructions for SlantRange 4P and 4P+ systems. If you are using a DJI Matrice 200 Series UAV the SKYPORT integration allows you to seamlessly twist & clip the sensor into its gimbal port. Follow this guide if you are using a different aircraft.

Mounting kits for M100 and M600 aircraft are available in the SlantRange shop.

1. The field sensor and AIS are directional and must be oriented forward throughout the flight
2. The field sensor and AIS must be mounted parallel to one another and oriented nadir in flight. This is accomplished by mounting at an offset to match the aircraft's forward pitch in flight.

Procedure

The field sensor and AIS are directional and must be oriented forward throughout the flight. The button faces forward on the AIS; the power plug and AIS connector face forward on the 4P and 4P+ field sensor. Ensure your mission planning software turns your aircraft 180 degrees after each pass, in a "lawnmower pattern" DO NOT fly forward on one pass, crab to one side, and then fly backward on the next pass.

The field sensor requires cooling airflow while in operation; mount on the aircraft so cooling airflow reaches the sensor. Do not leave the field sensor on for extended periods of time without cooling airflow (e.g. for several minutes on the ground before takeoff or after landing), and do not leave the battery connected when not in use.

Power

Connect the field sensor to a power supply, either its own external battery mounted to the aircraft or the aircraft’s onboard batteries via a power wire harness. The sensor will boot up as soon as power is connected.

The 4P and 4P+ are designed to accept 9-36V or a 3-6 cell battery. A rough estimate to calculate the sensor's "on-time" is to calculate the battery's total capacity and then divide by the sensor's power draw of 11W. The 11W is only drawn when the system is taking pictures (green light blinking); when the system is on standby it is drawing < 2W. For example, a 14.8V 1300mAh battery will power the sensor for approximately 1.75 hours of data collection (14.8V x 1300mAh = 19240 mW or about 19.2WH, 19.2WH / 11W = 1.75 hours of 3p ""on-time"").

Make sure the power cable running from the aircraft or external battery to the field sensor, and the AIS cable running from the field sensor to the AIS, are secured so they cannot contact the propeller blades in flight.

For further mounting instructions please refer to this article here. 

Preparing Your First Flight

1. Upon powering the sensor, wait approximately 10 seconds for the Cylon sequence of green, yellow, and red lights. This indicates the system is checking memory card status.
2. If there is a problem with your memory card, a solid red light will appear. If you see the solid red light, first make sure a memory card is inserted in the field sensor. If there is a memory card, run the Format SD card tool in the 4P Toolbox app as described in this Calibration video.
3. If your memory card is working properly, the Cylon sequence will change to solid green, yellow, and red lights. At this stage, you can connect to the sensor WiFi if running any of the 4P/4P+ Toolbox operations, or you can begin a data collection by pressing the AIS button.
4. To begin a data collection, press the button on the AIS. DO NOT shade the calibration sensor after pressing the button. If the aircraft is on the ground, make sure no one is standing over the aircraft or otherwise shading the AIS. The AIS MUST have an unobstructed view of the sky.
5. After pressing the AIS button, you will see a solid, then blinking yellow light, indicating pre-flight checks are being performed.
6. The blinking yellow light will give way to a solid green light indicating a GPS lock. The boot-up is complete, and you do not have to worry about shading the AIS on the ground. Make sure antennas or other aircraft components will not cast a shadow on the AIS in flight.
7. Once the solid green light turns to blink green, data is being collected and the sensor is ready for flight.
8. Please refer to the Flight Planning article before flying to verify you are using the preferred flight planning apps. 
9. Upon landing, press the AIS button, and a solid yellow light will appear briefly. Then solid green, yellow, and red lights will appear indicating a completed data collection.
10. Once you see the solid green, yellow, and red lights on the AIS, you can power down the aircraft (or disconnect the external battery powering the sensor). When the lights on the AIS go out, the sensor is shut down, and you can remove the memory card to transfer data.

The sensor will store approximately 3.5 hours of data before the AIS LED begins to blink red, indicating the sensor memory is close to capacity. After starting to blink red, the memory will reach maximum capacity after one more hour of data collection. To ensure the sensor memory does not reach capacity mid-flight, transfer and delete data from the memory card before you see the blinking red light.

For troubleshooting purposes, SlantRange may request the system.log file from the sensor.

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