“the on board surveyor” - drobit · drobit “the onboard surveyor” 2 introduction drobit is...

“The on board surveyor”

A PPK solution for drone-mapping

DROBIT “The onboard surveyor”

http://www.drobit.es

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Introduction

DROBIT is a high precision positioning system created for drone-based photogrammetry. Its

working principle is differential correction of GNSS kinematic trajectories. DROBIT has been

designed to be on board of an aircraft solving continuously the camera center position and

attitude and logging precise time marks for shutter actuations. The system allows to attribute

geo-coordinates to each photo center point with centimeter level accuracy, and this

consequently makes possible to perform photogrammetric surveys with no need for ground

control points. The final product typical accuracy is 3cm.

DROBIT is not just a device, but a turn-key geomatic solution composed of hardware, software

and methods in tight integration. It has been designed by a team composed of engineers in

Surveying, Photogrammetry, Computers, Electronics and Telecomms.

Main advantages

Speed up survey operations: The fieldworks involved on drone mapping projects are limited to

the time it takes to deploy the UAV and fly a preprogrammed mission. No need for spreading

and surveying targets any more.

Lower the cost of mapping: Time is money. DROBIT will not only reduce time on site but also

turns the field mission into a one man operation in most cases. Having high precision photo

locations also shortens dramatically the computer process time, because it eliminates the need

for marking CGPs on all images and therefore allows the full automation of the

photogrammetric workflow.

Safety is first. Dangerous areas are not void for drone-mapping anymore because no one needs

to enter. Are there lions there? Could this stockpile collapse? Do you need to map the mine

field? OK …no problem. Difficulties for accessing by ground to the area of interest will not be an

issue any more. DROBIT makes them irrelevant.

Accuracy improvement. It is commonly accepted that for geo-referencing of a set of aerial

images accurately, ground control measurement is required. Hence a good instrument and the

right methods to survey a well distributed collection of ground targets is mandatory. This is

generally true but is not the only way to go as DROBIT proves. The direct reference by camera

centers forming a uniform grid always gives the most robust and populated network of

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positional constraints. The even distribution of known points enables homogeneous accuracy

across the entire mapping area.

Hardware

In physical terms, DROBIT is a small footprint electronic device boasting a powerfull CPU

integrated with high quality geomatic sensors in barely 50 grams.

DROBIT HW not only interfaces with most types of cameras to acquire precise position and

orientation of itself, it does much more. It can control camera’s settings, download images,

automatically write geotags and can even trigger the camera autonomously.

The IMU integrated in the DROBIT board allows it to solve dynamically the camera center point

by considering the offset between the same and the GNSS antenna phase center. A three-

dimensional vector whose components are varying constantly as drone frame attitude changes.

This feature puts DROBIT system ahead of its competitors.

DROBIT allows the operator a high level of functionality related with planning, acquisition and

postprocessing of photogrammetry works. And those functions will expand with every firmware

upgrade we provide in the future!

DROBIT SYSTEM COMPONENTS.

Rover module: Designed to be mounted on board of the

vehicle and presented as an OEM board that can be bundled

with different mounting parts kits to ease the integration. It

comes with a low weight active antenna that should be

mounted conveniently in the upper part of the aircraft frame.

The on board module is complemented by accessories for

interfacing the camera trigger by wire with different plugs and

a small device that allows to detect the shutter actuation

instant by “sniffing” the flash firing signal through the hot-

shoe port.




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Base module: Composed of similar parts as the rover module but enclosed in an appropriate

housing for the electronics and battery. The enclosure has a ⅝” thread for mounting it on

standard surveying tripod or pole. The base module can be replaced by any survey grade GPS

receiver capable for output RINEX data at 5hz or higher frequency. (DROBIT reaches up to 20hz

raw output)

Both modules are operated by means of one single button and provide a simple interface

formed of four status leds. In addition they can be accessed and configured by wireless

connection from a computer. Once the module is powered, at the press of a button it begins to

record position and attitude and to monitor the payload actuations.

DROBIT PPK. Is the software tool we have created to ease the post-process of the logs and

photo files. Drag your cards folders onto the software main window and all calculations will be

carried out almost without user interaction. At the end a handful of files will be created including

a quality report, a kml file with a graph of the flight to be visualized in Google Earth, and a list

of photo names with their corresponding coordinates and estimation of accuracy.

Technical specifications.

ELECTRICAL INTERFACES

POWER 6V to 12V

TRIG IN Interface for input trigger commands from external hardware

(Autopilot, etc)

Contact closure to GND

TTL 3.3V

TRIG OUT & SYNC Trigger out command to Camera (both contact closure to

GND or PWM)

SYNC In from camera for precise geotagging

TTL 3.3V

Used with proprietary DROBIT HotShoe

UART TTL Uart for future expansions like RTK Radios

USB USB Click Mate connector for OEMs




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Physical

Board Size 71.1mm x 45.7mm x 11 mm

Board Weight 48g (excluding housing,

mounting/damping parts, batteries and

antenna)

CPU AND STORAGE

DROBIT mainboard has a Dual Core 500Mhz Intel Edison built-in.

SoC 22 nm Intel® SoC that includes a dual-core, dual-threaded Intel® Atom™ CPU at 500

MHz and a 32-bit

Intel® Quark™ microcontroller at 100 MHz

RAM 1 GB LPDDR3 POP memory (2 channel 32bits @ 800MT/sec)

Flash storage 4 GB eMMC (v4.51 spec)

WiFi Broadcom* 43340 802.11 a/b/g/n; Dual-band (2.4 and 5 GHz)

Bluetooth Bluetooth 4.0

External SDCard for storage expansion

GNSS RECEIVER

DROBIT mainboard is mated with a Comnav K501G GPS/GLONASS L1+L2 Receiver

Signal Tracking

Channels 120

GPS L1 C/A code,L1/L2 P code

GLONASS L1,L2

SBAS WAAS, EGNOS, MSAS,GAGAN

Performance Specifications

Cold start <50s

Warm start <45s

Hot start < 15s

Signal reacquisition <2s

Velocity Accuracy 0.03m/s

Acceleration 4g




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Overload 15g

Positioning Specifications

Post Processing Static 2.5 mm + 1 ppm Horizontal

5 mm + 1 ppm Vertical

Single Baseline RTK(<20km) 10 mm + 1 ppm Horizontal

20 mm + 1 ppm Vertical

DGPS 0.5 m 3D RMS

SBAS 1 m 3D RMS

Standalone Positioning Accuracy 1.5 m 3D RMS

Time Precision

GPS+GLONASS 20ns

Communications

Communication port 3 LV-TTL RS232 Ports, Baud rates up to 921,600 bps

Positioning data outputs 1 Hz,5 Hz & 10Hz

Raw data outputs 1Hz, 5Hz, 10Hz & 20Hz

PPS 1 Pulse Per Second Output

Event marker Event marker input

Indicating light 3 LEDs (indicating Power, Satellite Tracking and

Differential Data)

Data Format

Correction data I/O RTCM 2.x, 3.x. CMR (GPS only),CMR + (GPS only)

Position data outputs ASCII: NMEA-0183 GSV, RMC, HDT, VHD, GGA,

GSA, ZDA, VTG, GST, PJK, PTNL

Extended NMEA-0183 BDGGA, GPNTR, GPCDT,

GPHPR

ComNav Binary (compatible with major brands)




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INERTIAL MEASUREMENT UNIT

DROBIT is equipped with an onboard IMU that provides important orientation information that

is mandatory in order to calculate coordinates corrected to camera center.

IMU values are used to provide increased position accuracy and faster fusion position

estimations.

The IMU is a STMicroelectronics LSM9D with accelerometer data acquisition rate up to 1600 Hz.

Main features:

3 acceleration channels, 3 angular rate channels, 3 magnetic field channels

±2/±4/±6/±8/±16 g linear acceleration full scale

±2/±4/±8/±12 gauss magnetic full scale

±245/±500/±2000 dps angular rate full scale

16-bit data output

SPI / I2C serial interfaces

PRICING

Disclaimer: The following pricing scheme might be subject to changes according to options for

mounting, wiring and needs for customized parts required for integration.

VALUE ADDED TAX is excluded and will be 21% if applies.

DROBIT HW rover module 4000,00€

DROBIT HW base module 4500,00€

Custom Integration service available

If you have further questions, please request contact us at [email protected]


“the on board surveyor” - drobit · drobit “the onboard surveyor” 2 introduction drobit is...

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