Jam proofing drones

“Collect 1 million data points from a 15-minute flight compared to 300 points in a day from a traditional ground survey. It’s no wonder that drones equipped with GPS technology and remote sensors are revolutionising data collection. But will jamming spoil all the fun?”

Who let the drones out?

Recent years have seen the appearance of affordable, high-end drones which, coupled with easy-to-use mission-planning tools, has created the perfect environment in which drones can flourish. No longer the preserve of specialist drone users, applications using drones have been venturing into areas such as survey, inspection and volume analysis with an impact that is little short of revolutionary.

Interference can spoil it all

In the air, the stakes are higher. When things go wrong, the consequences are invariably much more serious than they would have been on the ground. One of the biggest threats to drone safety is GNSS interference. At the very least, disruptions to satellite signals can degrade position quality causing fall-backs from high-precision RTK and PPP modes to less-precise modes. In the most extreme cases, interference can result in complete loss of signal tracking and positioning.

Self interference

A significant source of interference on UAVs is often the other components installed on the UAV. The restricted space means that the GNSS antenna is often in close proximity to other electrical and electronic systems.

gopro_interference (1)

Figure 1: GoPro Hero 2 camera pick-up monitored by an AsteRx4 receiver

Figure 1 shows what happened to the GPS L1-band spectrum when a GoPro camera was installed on a quadcopter close to the GNSS antenna without sufficient shielding. The three peaks are exactly 24 MHz apart pointing to their being harmonics of a 24 MHz signal: the typical frequency for a MMC/SD logging interface.

An AsteRx4 receiver was used in this setup which includes the AIM+ system. As well as mitigating the effects of interference, AIM+ includes a spectrum plot to view the RF input from the antenna in both time and frequency domains. At the installation stage, being able to view the RF spectrum is an invaluable tool for both identifying the source of interference and determining the effectiveness of measures such as modifying the setup or adding shielding. For the quadcopter installation in this example, the loss of RTK was readily diagnosed and solved by placing the camera in a shielded case while the quadcopter was still in the workshop.

External sources of interference

GNSS receivers on-board UAVs can be particularly vulnerable to external sources of interference, be they intentional or not. In the sky, the signals from jammers can propagate over far longer distances than they would be able to on land.

In the case of UAV inspections of wind turbines for example, many countries encourage windmills to be built next to roads, a situation that increases the chance of interference from in-car chirp jammers. These devices though illegal are cheap and can be readily acquired on the internet. Using a chirp jammer, a truck driver can, for example, drive around undetected by the GPS trackers on the truck and car thieves can disable GPS anti-theft devices on stolen vehicles.

External interference: the effect of a chirp jammer on a UAV flight

Although transmitting with a power of around only 10 mW, chirp jammers are powerful enough to knock out GNSS signals in a radius of several hundred metres on land. In the air, the UAV is much more vulnerable as the jamming signals have a far greater reach, unhindered as they are by trees, buildings or other obstacles.

Figure 2 shows how a 10mW chirp jammer can knock out RTK positioning over more than 1 km in a high-end receiver. Even a low-end consumer-grade L1 receiver, being less accurate and thus less sensitive, loses standalone positioning over several hundred metres.

 With AIM+ activated, the AsteRx4 is able to maintain an RTK fix throughout the simulated flight as well as showing no degradation to its position variance. The full details on these simulations can be found in a recent white paper.

Solving interference on UAV systems

A comprehensive approach puts interference considerations at the forefront of receiver design and incorporates it into every stage of signal processing. In the case of the AsteRx4 and AsteRx-m2, the antenna signal is immediately digitised after analogue filtering and automatically cleansed of interference using multiple adaptive filtering stages.

As each interfering signal has its own individual footprint, being able to visualise the RF signal in both time and frequency domains allows drone users to identify sources of self-jamming and adapt their designs accordingly before the drone gets in the air.

When it is in the air, AIM+ is able to mitigate jamming from external sources: a set of configurable notch filters are complemented by an adaptive wideband filter capable of rejecting more complex types of interference such as that from chirp jammers, frequency-hopping signals from DME/TACAN devices as well as high-powered Inmarsat transmitters.


Figure 2: RTK position availability for the AsteRx4 with AIM+ activated and a comparable high-end receiver. The low-end receiver tracks L1 only and outputs less-precise standalone positions. A 10mW chirp jammer is located on the ground at position (0,0) as shown.

Targeting Interference with AIM+

 Radio interference is everywhere. GSM, LTE, FM broadcast radio, VHF/UHF communications, Wi-Fi, satellite phones and GNSS signals are all competing for a finite space on an already heavy populated radio spectrum.

The weakness of the GNSS signals makes them very vulnerable to radio frequency interference which can directly impact the quality of your measurements and the reliability of positioning. Even GNSS frequencies which are legally protected for military and civilian radio-navigation use are not immune.


These disturbances are usually very weak and your GNSS receiver is capable of extracting the necessary data from the GNSS signal. However, in many cases, the interference effect is more noticeable.

For example, radio navigation for assisting aircraft navigation and landing share their radio spectrum with one of the GNSS signal bands. The L5 band which has a centre frequency of 1176.45 MHz is shared by Distance Measuring Equipment (DME) and Tactical Air Navigation (TACAN). These radio beacons are deployed in the areas surrounding aerodromes and emit high-power radio pulses which can disturb GNSS receivers trying to use GPS and Galileo signals in this band.

At Septentrio, we devote considerable attention to interference throughout the design of our equipment. Working with customers over many years to solve real problems, we have developed Advanced Interference Mitigation (AIM+). These algorithms counteract the effects of interference. AIM+ is a standard feature of all Septentrio’s receivers including our newest reference receiver, PolaRx5.

AIM+ minimises the effects of continuous wave (CW) and narrowband interference on receiver performance. In the identification stage, the adaptive notch filter continuously scans the incoming signals for the presence of an interferer. Whenever an interferer is detected, the signal is digitally processed such that the interferer is suppressed.

One key element of AIM+ is the set of adaptive notch filters to target and eliminate narrowband interference on receiver performance.

A conceptual diagram of the adaptive notch filter is shown below.



Note that AIM+ can incorporate one or several adaptive notch filters, depending on receiver type. The core of the adaptive notch filter is a digital bandpass filter with an adjustable centre frequency. When an interferer is detected, a software-controlled switch (see Figure 1) routes the filtered signal to the remainder of the signal processing engine (suppression stage) instead of the input signal. During the suppression stage, the filter bandwidth is narrowed down and its centre frequency is fine-tuned. The installation process of the notch filter, including the fine-tuning of its bandwidth and centre frequency, is fully automated. If required, user controlled manual operation is also possible.

Septentrio recently won the tender to become the “preferred reference station vendor” to UNAVCO. In commercial testing of the PolaRx family with competitors, UNAVCO mentioned that:

            “Configuration of a notch filter to mitigate the interference was well documented and the effect of the filter was visible in the control software. The spectrum view feature can help users to rapidly identify the sources of RF noise and mitigate the using the built in mitigation tools”.

Septentrio delivers PolaRx5 GNSS reference receivers for volcano monitoring

TORRANCE, Calif. – Dec. 12, 2016 – Septentrio has completed delivery of PolaRx5 multi-constellation GNSS reference receivers and antenna systems to the U.S. Geological Survey (USGS).

The monitoring systems will be deployed through the Volcano Hazards Program (VHP) for volcano monitoring stations in Alaska and at various international locations through the Volcano Disaster Assistance Program (VDAP) – a cooperative effort between the USGS and the U.S. Agency for International Development’s Office of U.S. Foreign Disaster Assistance.

The PolaRx5 receivers take full advantage of the new 5.1.0 firmware which includes support for on-board PPP and dynamic response tuned for seismic applications. The PolaRx5 tracks all visible signals from Galileo, GPS, GLONASS, BeiDou, IRNSS and QZSS constellations. It provides industry-leading measurement quality and robust interference mitigation thanks to Septentrio’s patented AIM+ technology. The PolaRx5 supports these advanced features and more with a power consumption that is scalable from less than 2.0 watts.

“USGS and their partners will be among the first to exploit the PolaRx5’s seismic monitoring features,” said Neil Vancans, vice president of Septentrio Americas. “The PolaRx5 is Septentrio’s most complete GNSS receiver to date and provides the ideal upgrade for modernizing any continuously-operating reference station (CORS) network.”

More information about VHP and VDAP can be found via http://volcanoes.usgs.gov/index.html and http://volcanoes.usgs.gov/vdap respectively.

Disclaimer: Representations as to the capability of these commercial products are made by Septentrio.  The United States Geological Survey and/or other federal agencies mentioned above shall not be construed as having endorsed or otherwise recommended these products.

PolaRx5 CORS receiver

Septentrio PolaRx5 with NEW Firmware specifically designed for Seismic and Volcanology

About Septentrio:

Septentrio designs, manufactures and sells high-precision multi-frequency multi-constellation GPS/GNSS equipment, which is used in demanding applications in a variety of industries such as marine, construction, agriculture, survey and mapping, geographic information systems (GIS), and unmanned aerial vehicles (UAVs) as well as other industries. Septentrio receivers deliver consistently accurate GNSS positions scalable to centimetre-level, and perform solidly even under heavy scintillation or jamming. Septentrio receivers are available as OEM boards, housed receivers and smart antennas.

Septentrio offers in-depth application and integration support to make its customers win in their markets. Septentrio is headquartered in Leuven, Belgium, and has offices in Torrance, California, and Hong Kong, and partners around the world.

APS3G’s are marching out the door

Satisfying the RTK GNSS needs of provinces and water districts is demanding.

Today we prepare 2 x Septentrio APS3G’s using the Juniper Allegro 2 field tough computers to connect with an existing AsteRxU base receiver to provide RTK correction via the Internet.

Just over a year ago the water district engaged Elliott Enterprises to develop a solution for a city wide RTK GNSS system to provide accurate height data to design a 21st century water system to deliver water to the household at the right pressure on demand. After some testing and R&D we recommended an Altus Positioning System.

Upper Cases: 2 x APS3G Kits for Internet connection via GSM. Lower Case: APS3G RTK kit

Upper Cases: 2 x APS3G Kits for Internet connection via GSM.                        Lower Case: 1 x APS3G RTK kit Peer-to Peer UHF radio

The third case (on the floor) consists of 2 x Septentrio APS3G’s as an RTK GNSS Kit with a Juniper Allegro 2 field tough computer to operate Carlson SurvCE software for road design, drainage design and subdivision developments across a province.

The Altus Positioning System is chosen consistently for speed, accuracy and versatility in the most challenging surveys. With free firmware for the life of the receiver, the province will enjoy continued free upgrades and support for an even better survey solution for many years to come.

Call Nelia Elliott on 0917 557 971 to join our business family!

Septentrio receiver tracks newest Japanese GNSS signals

Hong Kong – 12 October 2016Septentrio and its Japanese partner, GNSS Technologies, are proud to announce that they have successfully tracked and decoded the QZSS LEX signal. This achievement marks a milestone in the development of the Japanese QZSS satellite navigation system and is the result of a trusted partnership between Septentrio and GNSS Technologies. The partnership is committed to enable the success of their Japanese customers with the very latest in satellite navigation technology.

QZSS (Quasi-Zenith Satellite System) is Japan’s regional satellite navigation system. When completed, it will consist of 4 satellites: the first satellite was launched in 2010 and the remaining three are scheduled to become operational in 2017. All satellites will be equipped with a revolutionary CLAS (centimetre-level augmentation service). This service will send correction signals straight from the QZSS satellites to end-user receivers and enable them to calculate their position with centimetre-level accuracy. The CLAS corrections are broadcast in the LEX and L6 signals.

By implementing LEX signal tracking and decoding before the completion of the QZSS constellation and before the CLAS service becomes operational, Septentrio and GNSS Technologies are showing their long-term commitment to Japanese customers.

Using Septentrio technology, customers will be able to eliminate the need for investment in ground infrastructure to create correction signals or in subscriptions to commercially available correction signal streams. This opens up possibilities in new application domains in sectors such as marine, construction, agriculture, survey and mapping, geographic information systems (GIS) and unmanned aerial and vehicles (UAVs).

All NEW Juniper Geode submeter GPS receiver

Today, Juniper Systems would like to introduce to you… the Geode™ – our new real-time, sub-meter GNSS/GPS receiver! This compact, all-in-one receiver collects precise location data, without the huge price tag or complexity of other precision receivers. We designed it with an emphasis on simplicity so you can start collecting data at the touch of a button. The Geode is also highly versatile, and will connect via Bluetooth with Juniper Systems’ rugged handhelds, or any other Windows®, Windows Mobile, or Android ®device. Speaking of versatility, the Geode can also be carried in a number of different ways. It can easily be carried in-hand, in a pack, or mounted on a pole, depending on your specific use case and what your individual needs are.

Geode Real-Time Sub-meter GNSS Receiver

Geode Sub-Meter GPS ReceiverAnd of course, the Geode doesn’t compromise on ruggedness. It features IP68-rated protection against water and dust, and operates in extreme temperatures, providing reliable performance wherever you need to collect data.

Here are a few other Geode features:

  • SUB-METER ACCURACY – Collect precision GNSS data with your handheld device
  • REAL-TIME DATA – Multiple correction sources provide precise, real-time data
  • JUNIPER RUGGED™ – IP68-rated and designed to withstand harsh environments
  • AFFORDABLE – Professional accuracy at a budget-friendly price
  • COMPACT SIZE – Small and lightweight for all-day use
  • OPEN INTERFACE – Works with Juniper Systems’ handhelds or your own device
  • SIMPLE TO USE – Intuitive and easy operation, one-button simplicity
  • ALL-DAY BATTERY LIFE – Ideal for long work days
  • CONNECTIVITY OPTIONS – Connects to a handheld or tablet via Bluetooth or an optional 9-pin RS232 port
  • BUILT-IN ANTENNA – Comes with a built-in GNSS/GPS antenna, but also includes a port to connect an external antenna, depending on the user’s preference

Juniper Systems’ products are designed to reliably collect data in any environment,” said Debbie Trolson, Geomatics Market Manager at Juniper Systems. “Whether users need a GNSS solution that provides 2–5 meter accuracy, or one that provides even more precise, sub-meter accuracy, Juniper Systems can deliver a high-quality solution that enhances both productivity and data integrity.”

Juniper Systems Partnership in Pinoy

The Partnership between Elliott Enterprises and Juniper Systems, USA was agreed and finalized this week.

Desmond Elliott, Support and Training Manager at Elliott Enterprises and  Debbie Trolson, Geomatics Market Manager at Juniper Systems completed the Agreements for a Partnership to Supply and Support Juniper Systems products in the Philippines.

Juniper Systems products include:

  • Juniper Archer 2 Field Rugged Data Controller – Simple to use, Low cost, Rugged Field Computer providing excellent battery life between charges.
  • Juniper Allegro 2 Field Rugged Controller/Computer for Surveying and Engineering. With a Number Pad and QWERTY keyboard makes this Field Rugged Hand-held computer is the BEST available in the industry.
  • Juniper Mesa 2 – the latest Rugged Field Notebook, using the Windows 10 operating system, users can take their GIS software to the fiels – Sporting a 168mm Touch Screen this has to be a part of every field kit.
  • Juniper Geode released in July, a rugged compact Submeter GPS/Glonass GNSS receiver. Ideal for GIS applications the receiver provides 300mm accuracy using SBAS correction and 50-70mm accuracy using a reference station or post-processing.

These products plus more are now available from Elliott Enterprises where we provide Support, Training and Carlson SurvCE software to convert them to a dynamic flexible GIS and Surveying data collector. Importing and Exporting GIS and Point data is as simple as pressing a button.


New Channel Partner…..

We are proud to announce a NEW Channel Partnership with BSPH MARKETING, Philippines.


Bentley Map – GIS

On Thursday the 21st of July, 2016, Nelia and Desmond Elliott of ELLIOTT ENTERPRISES met with Eloisa Mabuyo of BSPH MARKETING in General Santos.

BSPH MARKETING a (Bentley Channel Partner) are Marketing, Consulting and Supporting Bentley software in the Philippines  

During this introductory meeting a Channel Partnership was agreed. The meeting and agreement brings together many years of experience between Professional Software and Professional Positioning Hardware teams.

BSPH MARKETING market Water GEMS and Energy Infrastructure software solution for Electricity Generation, Supply and Distribution companies and Water Supply and Distribution companies across the Philippines. Using Bentley software from the USA,  Lurlene Del Rosario her partner Eloisa market, consult and train company personnel in the use of the software to manage infrastructure networks and integrate costing and charging processes. They are now introducing Bentley GIS software to manage the assets and user needs.

WaterGEMS software

Elliott Enterprises were approached to fill a role, providing accurate positioning equipment (Altus GNSS surveying equipment, Juniper data collectors and Carlson field collection software) to collect survey and GIS data quickly, accurately with efficiency. With our reputation in supplying the latest technology in GNSS and Laser positioning plus our technical capabilities in integrating data collection and GIS data management the partnership is perfect.
To achieve high accuracy in the computation of power and water network design and optimization the necessity for high accuracy positioning is paramount to the success of the solution. The Septentrio/Altus Positioning System is the best equipment for these projects – offering the highest accuracy specifications in the industry..
iStock_000004608305Medium copy

Septentrio/Altus Positioning Systems in the Field

We would like to inform existing clients and potential partners in the Water and Power industry that “we Support and we Care” This is our promise and our pledge in providing a professional service with Integrity. We look forward to working closely with BSPH MARKETING to provide the best possible solution to all existing and future infrastructure and management projects.


The Chirp Jammer: a GPS hit and run

Published by Septentrio Inc.on 16-06-2016 


The €50 device that brought a multi-million euro project to a standstill

You’ve got your base station setup in an open environment, its position has been properly surveyed and it’s tracking signals from all satellites visible overhead with good signal-to-noise levels. What could possibly go wrong?

Here’s what can and did go wrong on one building site in 2015. A major construction project was underway, an army of excavators, bulldozers, piling rigs and graders were operating in a confined area with their activities carefully orchestrated by an RTK guidance system. The foreman knew the position of each vehicle down to the centimetre. Without warning, GNSS positioning was lost, warning messages appeared on the screens of the operators’ guidance units and work ground to a halt resulting in days and weeks of machinery down-time and lost man hours.

The culprit: Personal Privacy Devices

The construction site was close to a busy thoroughfare frequented by commercial vehicles whose movements are often monitored by tracking devices that include a GNSS receiver. Such devices ensure for example, that drivers don’t exceed legal driving times or avoid road tolls. 

Recent years have seen an increase in drivers turning to cheap GNSS jamming devices, such as those shown in Figure 1, in order to move around undetected or to thwart built-in anti-theft systems.


The problem is that, although these GNSS jammers or PPDs (Personal Privacy Devices) are low power, GNSS signals are even lower power. One PPD powered by a 12 V car cigarette lighter socket is powerful enough to knock out GNSS signals in a radius of several hundred metres. With the increasing use of GPS trackers for insurance or road tolling, the number of jamming incidents has increased significantly in recent years.   

A recent report from the Homeland Infrastructure Threat and Risk Analysis Center (HITRAC) of the Department of Homeland Security (DHS) documented the case at Newark Liberty Airport in 2011 where a PPD caused harmful interference on the new GPS-based landing assistance system. Subsequent monitoring has since confirmed an  average of 5 interference events per day. According to the report, PPDs are considered to be among the 3 biggest threats for GPS/GNSS disruption


GNSS is more than positioning

GNSS applications have long surpassed positioning. GNSS has established itself as part of the critical infrastructure in areas as diverse as cellular communication, where providers use GPS time to manage communications between mobiles phone and phone towers, to banks and stock markets who use GPS to time-stamp their transactions to help prevent fraud.

The effect of Personal Privacy Devices on GNSS signals

Most cheap in-car PPDs transmit a chirp signal which is a signal that changes frequency rapidly over time. In this way, a signal with a rather narrow bandwidth can cover large swathes of the GNSS spectrum. Figure 2 shows the effect of the signal from a chirp jammer on the GPS L1 band. The region between 1565 and 1585 MHz is dominated by the jammer effectively swamping the GPS L1 signal.


The Septentrio solution

The intermittent nature of most jamming events makes them difficult to detect and even more difficult to diagnose. That’s why Septentrio offers built-in protection against intentional and unintentional jamming in its GNSS receivers. As part of our patented Advanced Interference Mitigation (AIM+) technology, a sophisticated system of sampling and mitigation mechanisms has been developed called WIMU (Wideband Interference Mitigation). The red trace in Figure 2 shows the dramatic result when activating WIMU in the presence of interference from a chirp jammer. More details on WIMU can be found here.

The benefit to the user

The effects of WIMU are also illustrated in the Figures below. The white triangle indicates the location of a 10 mW chirp jammer in the centre of Tampa and the red zone is the region in which the jammer knocks out the GNSS signal. When WIMU is enabled on an AsteRx4 receiver for example, the ‘No RTK Zone’ indicated by the red region, is reduced from several hundred metres to a few metres effectively confining the range of the jammer to inside the car it’s plugged into.


Uptime guaranteed

AIM+ technology brings considerable cost benefits to users of Septentrio’s GNSS solutions. Whether in urban or rural locations, on construction sites or piloting a UAS, the detrimental effects of PPDs and other sources of jamming can be considerably minimised thus reducing downtime and costs due to lost man hours.

AIM+ is available on the following Septentrio GNSS solutions: PolaRx5AsteRx4AsteRx-U and the Altus APS3G.

Jamming of GNSS signals is illegal in most countries. If you suspect that jamming is an issue in the area where you work, please report it to the local law enforcement authority. 

(Title Image: Wing)


20 Things They Don’t Tell You About UAVs

Elliott Enterprises suggest investment in an extra GNSS Rover or two (much lower cost than a UAV) to collect more topographical data….unless the projects justify the risk of loss of equipment, poor results and operational cost, amortization of purchase cost plus initial training and licensing required to perform UAV photogrammetry professionally….the risk is much higher than the rewards!

Neil Vancans and Doug Daggermond - UAV

Jack Dangermond, ESRI and Neil Vancans, Septentrio admire the Septentrio enabled C Astral UAV at Esri UC 2016

I have worked on projects with Mark Deuter’s company, AEROMETREX (the author of the blog) as a mapping and survey consultant in Australia.  AEROMETREX are an industry leader in photogrammetry and are respected across Australia. Their client portfolio consists of goverment, mining, environmental and real estate mangement.  by Desmond Elliott

To UAV or NOT to UAV…! by Aer0metrex_admin

RQ-84Z AeroHawk UAV system at hte end of a mapping mission.The energy, enthusiasm and the inventiveness that is going into UAV* technology these days is truly remarkable. There has been a proliferation of manufacturers, suppliers, users and conferences promoting the technology. We have all seen stunning video clips and images taken from UAVs – the low altitude aerial perspective enables unique views of a wide sweep of surrounds as well as the foreground focus of attention.

In July 2012 I attended the ESRI International User Conference in San Diego and assisted a UAV manufacturer on their trade exhibit, fielding questions from potential customers of this technology. It was a revelation, not only because of the technology, but because of the reaction of the punters. I could see it in their eyes. Everyone wanted to do this for a job. “Get paid to have fun? I’m in!”

As a long-standing aerial surveyor I have watched the rise of UAVs with an open mind. Indeed the company that I part-own and work for is a CASA-registered UAV operator and we have invested heavily in the technology. We know what it takes to make a good UAV aerial survey and we can show some great examples of our work. However we are in the somewhat unique position of being able to compare the cost-effectiveness and the results of UAV aerial surveying against the latest full-scale aerial surveying equipment and methodology, because we have both capabilities.

I can say right here and now that the concept of UAVs as a platform for aerial surveying is suffering from a typical problem that plagues new technologies. It’s over-hyped. Yes, you can take an aerial photograph with a UAV. Yes, that photograph can be used to map an area of interest. But no, in 99% of cases you cannot do it as well, as fast or as cheaply as you can with a large-format aerial camera in a conventional fixed-wing aircraft. That may surprise you but it’s true.

With apologies to Ha-Joon Chang, the author of the excellent book “23 Things They Don’t Tell You About Capitalism” ** I have set out here 20 things they don’t tell you about UAVs.

Please note that in this article we are referring to very small to small UAV ( A very small UAV is defined as an unmanned aircraft of mass smaller than 2 kilogram –  A Small UAV is defined as an unmanned aircraft of mass greater than 1 kilogram yet less than 150 kilograms (fixed wing) or 100 kilograms (rotary wing)).


Thing #1. A UAV is just a platform for a sensor

A lot of discussion in the UAV industry revolves around which UAV is best. Every manufacturer stridently proclaims the advantages of their system in terms of battery life, stability, payload, range control functions, etc. But hardly anyone acknowledges that a UAV is just a platform for a sensor. We don’t make a big fuss about whether we use a Cessna 441 or a Cessna 404 or a Piper Navajo to fly your aerial survey. To us an aircraft is just a means of positioning a sensor. It’s not about the aircraft, it’s about the sensor.

Thing #2. A small UAV carries a small payload which means small format sensors

There is no doubt that you can cram lots of megapixels into a compact camera or a DSLR these days. But even a 36MP DSLR camera is small format compared to the latest generation large-format aerial mapping cameras, at 360MP or even bigger. Small UAV = small format sensor = lots more runs and photos = inefficient capture.

Thing #3. A $1,000 sensor is not as good as a $1.5m sensor

There are sensors and sensors. Most UAV systems carry small compact cameras to eke out precious payload. More sophisticated systems may be able to carry a DSLR camera. But these are non-metric consumer grade cameras, with uncalibrated lenses, prone to temperature variation, with limited storage on-board and using Bayer-filtered 3-band RGB imaging systems. They are not to be compared with modern aerial mapping cameras which have much bigger formats, separate lens cones for each multispectral channel, often in 4 bands (R,G,B and NIR) along with dedicated panchromatic cones, which have geometrically calibrated lenses with known distortion characteristics, with gyro-stabilised mount correcting level and drift, with almost unlimited storage and extremely sophisticated airborne GPS, IMU and navigation systems. Not surprisingly, a $1000 sensor is just not as good as a $1.5m sensor.


Hawkeye-UAV groundstation

Hawkeye-UAV groundstation

Thing #4. A UAV is not unmanned

Strangely, an Unmanned Aerial Vehicle is not unmanned at all. The men/women are on the ground. Hence the new terminology RPAS (Remotely Piloted Aerial System). There are usually two operators, just the same as the aircrew in a light aircraft. Where is the saving? 

Thing #5. Labour costs make small UAVs uncompetitive

Do the maths. Don’t forget to include the time and cost of getting the UAV operators to and from the survey area, the time needed to conduct the survey, the costs of accommodation and travel allowances, and the cost of masses of GPS ground control. As well as the salaries for 2 skilled people (UAV operator, surveyor). Adds up pretty quick. We reckon it’s more efficient to get a large-format system in for anything bigger than a few km2, even if you’re right there on the spot with a UAV.

Thing #6. UAVs are justifiably limited by airspace regulations

CASA (Australia’s Civil Aviation Safety Authority) is very concerned about the prospect of an airspace swarming with UAVs and has imposed strict limits on commercial UAV operations. We have already seen one instance in which a UAV operator (not us!) lost control of a UAV which flew across the flight path of a military airport. And one has now hit a jet aircraft in flight.

UAVs may only be operated by CASA-certified operators and can only legally be operated as follows:

  • Not above 400’

  • Not over a populated area

  • Not within 3.5nm of an airport

  • Not outside VLOS (Visual Line of Sight)

unless specific approval has been granted. These applications are considered on a case-by-case basis by CASA and the waiting period for a response was out to several weeks last time we applied. Fact is, if you operate legally there are not many places you can fly a UAV commercially.

Thing #7. Line of sight is no more than 500m

Try spotting a small UAV flying away from you. It takes about 15 seconds to completely disappear. Therefore run length is limited to 30s flight time, unless you station observers along the flight path equipped with radios for back-to-base comms.  This has been tried. See Thing #5. 

Thing #8. You will need formal training to operate a UAV legally

To be qualified as a UAV operator, you will need:

  • Basic Aeronautical Knowledge (BAK) or Private Pilots Licence (PPL).

  • Radio operators licence

  • Manufacturer training on type

and then pass the CASA exam. You can’t just take it out of the box and start flying.

Thing #9. A UAV is capable of killing you

Our small UAV system weighs 3.8kg (the same as a brick) and it travels at up to 120km/hr (33m/s). If it hits you in the face at that speed it will decelerate almost instantly, say in 0.1s.  No laughing matter.

My high school physics tells me Force = mass x acceleration.

So F = 3.8kg x (33/0.1) m/s2 = 1,254 Newtons. In the face.

Serious injuries have been caused by powerful UAV propellors and, as was demonstrated by Mythbusters recently, a large multi-rotor UAV propeller could sever an artery. There are a number of accounts on the web of unmanned helicopters decapitating their operators. Check your training, your safety systems and insurances. Don’t think they are too small to hurt anyone.

Thing #10. UAVs suffer from local environment effects (especially wind)

UAVs are very small aircraft and subject to forces that would not affect larger aircraft. Wind is especially problematic for small UAVs, and wind is often stratified, ie, much different even at 400’ than it is at ground level. Weather forecasts are usually published for ground level conditions. Can you really keep your UAV on track? Will your UAV be able to grind its way back to base in a 40 knot headwind?

Thing #11. The logistics of UAV operation are problematic

Think again if you are planning to provide a UAV service in remote areas, which if Thing #6 is properly observed, is where you will end up. Do I drive or do I fly to the site? If it’s too far to drive or the roads are rubbish, or don’t exist, perhaps I could get there in a light aircraft, or a helicopter? Wait …

Thing #12. Blurry images cannot be used to generate accurate results

We are sometimes asked to save UAV surveys which are comprised of blurry, badly exposed imagery.Lack of detail destroys the effectiveness of image matching algorithms, resulting in lack of tie points and geometric accuracy. Such surveys are usually unsalvageable and must be reflown.

Thing #13. Eagles hate UAVs

With a passion. The last thing any self-respecting eagle will tolerate is another predator blundering through its territory not even bothering to look up – the arrogance! Eagle hits on UAVs are common. See Thing #14.



Thing #14.  The capital cost of a UAV is significant

A sophisticated UAV is likely to set you back anywhere from $30,000 to $100,000. Let’s say you get a bargain at $50,000. What is its useful life? 200hrs? Let’s amortise that cost over 12 months assuming you’re a skilled pilot and can run the gauntlet of crashes resulting in total loss that long. It will cost $260 per hr in capital burn alone. About as much as the total running cost of a Cessna 172. 

Thing #15.  UAV crashes are common

The stories are mounting. UAVs escaping, getting lost, slamming into mine walls, crash landing, etc, etc. All expensive stuff. What is the life of a UAV system? Who knows? Only as long as your next uncontrolled event.

Thing #16. UAV insurance is hard to get

Not unrelated to Thing #15. UAV hull insurance (the aircraft and payload) is usually uneconomic and most operators insure for public liability risk only. That means a crash is usually a loss borne by the operator, and will add tens of thousands of dollars to your depreciation for the year. Hope you weren’t still paying off that loan. Please tell me there aren’t any UAV operators flying without Public Liability insurance. That would be financial suicide. See Thing #9. 

Thing #17.  You will need Professional Indemnity Insurance if you offer an aerial surveying service

Don’t even think about offering your services to a mining company or other engineering firm if you don’t really know what you are doing and you don’t have PI insurance. Your clients have too much money at stake. An error in calculation is a recipe for financial ruin. PI insurance is both expensive and necessary.


Thing #18.  If you’re not skilled in photogrammetry, you’re not an aerial surveyor

Most registered UAV operators optimistically put ‘aerial survey’ as a work category on their CASA application forms. Aerial photographic surveying is an exact and demanding science. A thorough understanding of photogrammetry is required to offer these services. Photogrammetric qualifications are usually offered as an advanced specialisation of a Surveying Degree. Buying a software package that promises centimetre accuracy does not enable anyone to become an overnight expert.  There are many traps for the unwary and industry best practice and university qualifications cannot be ignored.

Thing #19.  Airborne GPS and IMU for UAV are not accurate enough for direct geo-referencing

The Airborne GPS and Inertial Measurement Unit (IMU) technology that has been used in large-format digital aerial cameras since 2005 is the same technology that is used in guided missiles. Not surprisingly, some of it is embargoed by the US State Dept. It’s very sophisticated. The resolution of these measurement systems is very precise and is vital to determining the accurate position and attitude of the camera in flight. While advances have been made in the miniaturisation of these devices for consumer application in smart phones as well as UAVs, they really lack the resolution needed for accurate measurement.


Thing #20.  While we’ve all been watching UAV developments, other things are happening

The developments that have taken place in our industry are profound, and we should be very proud of them. But they are not really to do with UAVs at all. They are things like:

  • Much more efficient sensors. The Ultracam Eagle Prime, and the A3 Edge come to mind. Huge aerial camera sensors with outstanding capture efficiency and storage.

  • 3D models – the base map of the future. Great advances have been made in the accuracy, realism and applications of 3D models during the last 4 years. The transition from 2D to 3D mapping systems is happening faster than you think.

  • Automated processing and data extraction from aerial imagery.

These developments are the real direction of the industry and where we should be focussing more resources.


RQ-84Z AreoHawk UAV after take-off

RQ-84Z AreoHawk UAV after take-off

The UAV industry is what it is – there is no doubt that UAVs have many intriguing applications in many fields, although we have seen the existing service providers back-pedalling from things like pizza delivery or parcel delivery. At the current rate of development and with the concentration of resources being applied to the industry there is no doubt that further advances will be rapidly made.

But beware of the hype, and remember, in our industry it’s not about the platform, it’s about the sensor.  

Author: Mark Deuter, Managing Director AEROMETREX