Balloon News sponsors Royal Meteorological Society competition

Near Space Photography is sponsoring a competition to promote the investigation of the atmosphere. The Royal Meteorological Society has invited 11-16 students to design and build a science experiment to be carried through the atmosphere by a weather balloon.  Themes for the competition could include Earth observation, the atmosphere, Natural forces, cold temperatures, pressure or UV. Students could use a Raspberry Pi, or similar, to design and build their own tracker and/ or sensor package.
All entries must be submitted to the Head of Education at the Royal Meteorological Society by 17th February 2017.
The entry judged best by a panel of judges will be invited to build and launch their experiment.

We are providing some resources for the competition at https://balloonnews.wordpress.com/competitions/resources/

 

 

More ways that a high altitude balloon flight can go wrong

Two years ago I wrote an article on how a high altitude weather balloon flight can go wrong. I like to periodically update this article when I come across more ways that balloon flights can go wrong. Here I would like to include the ‘slow puncture’. During balloon inflation or manufacture, weather balloons can develop small holes that cannot be spotted during balloon inflation. If a weather balloon has a small hole then the lighter than air gas will obviously escape after launch. This may not become apparent until you have let go and notice that your balloon ascent rates are unusually slow. The general consequence is that as the balloon expands, gas will escape. This will lower ascent rates to the extent that it will probably not reach a point where is fails by bursting. Thus is will slowly and steadily ascend, then slowly and steadily descend.

I have had personal experience of this. I did a flight for a cosmetic company, launching a balloon close to Milton Keynes. The balloon ascended for 25 minutes then slowly descended for 25 minutes. We recovered it from a recently harvested field, bobbling about with the balloon partly inflated. This can be a real hazard, greatly increasing the chance of entanglement in power or telegraph lines.

I also have the experience of watching a flight from Warrington. Here the leak was much slower. The balloon ascended for well over an hour. It then slowly descended. By the time it reached ground level, it had drifted out into the North Sea; much further east than the forecast showed. This payload was lost.

 

KingsHAB flight from Warrington. Summer 2016. Note the altitude profile is symmetrical.

 

There are few ways to overcome this problem. You can listen out for gas leaks after balloon inflation but may not be able to hear micro leaks. You can routinely use a balloon cut off such as Doongara; set to remove the balloon after a set period of time. This would have certainly helped avoid the total disaster that the flight from Warrington experienced.

 

 

Go Pro Hero 5 – is it useful for high altitude ballooning?

 

Go Pro has released the latest version of it’s popular action camera series which has been used extensively in high altitude ballooning. The last iteration, the Hero 4, no new features for high altitude balloonists. Let’s see if the Hero 5 offers more by comparing it to the Hero 4.

First off here are a few broad reviews of the camera for terrestrial photographers:

http://www.gizmodo.com.au/2016/10/gopro-hero5-review-a-more-perfect-action-camera/

http://www.trustedreviews.com/news/gopro-hero-5-release-date-4k-waterproof-specs-features-price-news-rumours

http://www.valuewalk.com/2016/10/gopro-hero-5-black-vs-gopro-hero-4/

https://havecamerawilltravel.com/photographer/gopro-hero5-black-vs-hero4-black

 

Now let’s go through some of the new Hero 5 features and see if they improve your HAB photography.

Weight

The standard weight of the Hero 5 black is 118g including it’s integral housing. This is heavier than the previous models. The housing also makes the Hero 5 larger than previous models but I have been consistently flying mine in their extended housing to protect battery bacpacs, so there is no great change here.

Touch screen

There is no great advantage in the touch screen and now that I am used to interfacing with my Hero 4 through the app, the touch screen adds unnecessary weight and power consumption.

Voice control

As with the touch screen, this has no value.

 

Video

There’s a lot of overlap between the video modes of the HERO5 Black and its predecessor. They share top-end video modes of 4K30, 1080p120, and 720p240.

Video Stabilisation

This is one of the headline features of both the HERO5 Black and the HERO5 Session. It’s designed to smooth out the jerkiness you can get with unstabilised footage.

I’ve found it to work pretty well in many cases and very well in others. So long as you’re realistic about it, of course. It’s a software solution that does in-camera something similar to the Stabilization feature in Final Cut Pro or Adobe Premier’s Warp Stabilizer.

This may help if the balloon passes through particularly turbulent air… but don’t expect your footage during balloon burst to be any smoother.

Video resolution

There is no great improvement in video resolution from the Hero 4.

 

Video Resolution

Fields of view

Where there are some differences is in the fields of view, or FOV, offered. The most significant difference is that the HERO5s offer a new Linear FOV that removes fisheye distortion in-camera. This is also available on the still photography. So if you are tired of the lens distortion effect on your images then this would be a camera to try.

 

Still images

Both models have a maximum image size of 12MP (4000 x 3000 pixels). The new Hero 5 camera offers little improvement in the sharpness of images. If you do have the time and patience to post process the images then you may be interested in the RAW image function of the new Hero 5.

Battery performance

This is one of the most contentious features of every camera as it impacts on how long you can use the camera. This is really critical in high altitude ballooning where you cannot just pop another battery in.  The HERO5 Black uses a new, slightly higher-capacity battery (1220mAh vs. 1160mAh). Combined with more power efficient operation, you can get significantly better performance. BUT, some reviews have stated that the battery performance is just less than that of the Hero 4. More critical is the ability to extend battery life. It seems that the Hero 5 does not have a standard battery bacpac. To extend battery life you need to feed in a non standard external battery through the micro usb port.

 

Review

The Hero 5 offers just a few additional features that are of interest to high altitude balloonists. One of the key improvements is the ability to offer a linear field of view… though this does mean that you won’t be tricking people into thinking that your video shows genuine Earth curvature. But maybe our audience needs a reality check. One big barrier to me buying this camera is battery performance. Most of my flights last in excess of 150 minutes. This camera will not be capturing the payload landing unless I attach a third party battery pac.

 

Buy or No Buy?

 

No buy …unless I need to use the linear field of view.

 

 

 

 

 

 

 

Uputronics release new, improved, and lighter PITS tracker

Uputronics have released a companion to their successful radio tracker, the Pi in the Sky; based on the popular Raspberry Pi computer. At the centre of the new tracker is the cut down Raspberry Pi Zero. The complete PITS  Zero radio tracker includes many of the features of its bigger brother but at less than half the weight (110g including batteries). This includes:

• Efficient built-in power regulator providing run time of over 20 hours from 4 AA cells
• Highly sensitive UBlox GPS receiver approved for altitudes up to 50km
• Temperature compensated, frequency agile, Radiometrix 434MHz radio transmitter
• Temperature sensor
• Battery voltage monitoring
• Sockets for external i2c devices, analog input, external temperature sensor
• Allows use of Raspbery Pi camera
• Mounting holes and spacers for a solid connection to the Pi

For those that don’t want to play with electronics, the kit comes with all the essential components, including the Pi Zero and operating system on a memory card. It also differs from the standard PITS tracker in having LoRa protocol transmission included as well as RTTY.

The PITS Zero comes at an increased price tag of £240, compared to £132 for the standard PITS tracker. This price differential can be understood in part due to the inclusion of the Pi Zero and memory card. However, if you cost out a standard PITS at £132, LoRa expansion at £27, and Raspberry Pi at £35 then you have an equivalent complete PITS cost of £194.

 

VentuSKY – visualising wind

VentuSKY is a new web based tool to visualise wind data across the Earth. VentuSKY has been developed in the Czech Republic by InMeteo. It provides an effective way of visualising wind data so balloonists planning a launch can quickly identify if a launch site will have strong winds and some altitudes where balloon flight may be turbulent. While it is not a substitute for conventional meteorological forecasts, it  helps balloonists get a now cast on flight conditions.

Doongara – the next generation of thermal line cutters.

Smith and Williamson, the Oregon based tech company who developed the Boomerang controllable balloon valve, are now marketing their next product, the Doongara thermal line cutter. We first covered ‘off the shelf’ thermal line cutters for balloons in 2014 with the modified Zlog 7 from Hexpert. This was based on the original Zlog 7 gps data logger with a relay activating a nichrome wire thermal cutter. The device was effective but large and clunky; requiring two 9v batteries. One 9v battery for the gps data logger and the other for the line cutter. Given it’s weight and size though, it was hard to place close to the balloon line above the parachute. Doongara overcomes the issue of size and weight by relying on a barometric pressure sensor, thus requiring only a single AA cell for power. It also comes with a unique set of nylon cord to simplify the cut down process.

Here is some more information about Doongara from the Smith and Williamson web site:

Doongara is powered from a single AA battery and cuts line based off of user-programmable settings: elapsed time, barometric pressure, and/or rate of pressure change. Features include:

Small Tandem Balloon

• Integrated sensors with on-board data storage:
  • Barometric Pressure, Temperature
• Redundant burn-wires
• Battery heater
• Duration >3 hrs
• Light-weight at less than 40g, including battery

Single Doongara Applications:

• Cut-away “tow” balloon for Constant Rate Descending Flights
• Drop a sonde or ballast during flight
• Terminate a conventional flight at a specific pressure altitude
• Separate from balloon remnant after burst

Tandem Doongara Applications:

• Cut-away “tow” balloons and terminate for Level Horizontal Flights
• Cut-away “tow” balloons and terminate for Stepped Vertical Flights

 

 

Smith and Williamson have been kind enough to give us a Doongara to test fly. So we will be using it to drop a simple secondary payload from a primary payload. We will also attempt a tandem flight using the Doongara to separate the tow balloon.