We lately launched the RTK Postcard, able to quadband reception. In the present day we’re gonna speak about what quadband is, why multiband reception is nice for accuracy, and what different merchandise we’ve that may get you there.
We’ve bought a variety of merchandise that speak about bands – we simply launched two merchandise that includes Quectel’s LG290P, the RTK Postcard and the Quadband Breakout Board. We even have merchandise that boast triband reception, just like the RTK Torch and the mosaic-X5. We talked about L-band a number of months in the past, the frequency at which GNSS communications are despatched from satellites. However now that we all know what bands are, why do we would like extra of them? Effectively, I’m glad you requested.
What are GNSS Bands?
GNSS indicators are broadcast over a number of frequency ranges throughout the L-band, these ranges are known as “bands.” L1, L2, and L5 are widespread GPS bands that every one transmit several types of information. As we talked about in our weblog about l-band, we use this frequency band as a result of these frequencies are low sufficient to penetrate atmospheric layers successfully, however excessive sufficient to offer dependable information transmission, even in difficult environments like forests or city areas. The time period “band” refers to a selected vary of frequencies throughout the radio spectrum. This terminology originates from radio engineering, the place all the electromagnetic (EM) spectrum is split into frequency “bands” (e.g., VHF, UHF, L-band) primarily based on traits, regulatory allocations, and customary makes use of..
In the present day, different GNSS constellations—reminiscent of Galileo (Europe), GLONASS (Russia), and BeiDou (China)—have their very own allotted frequency bands throughout the L-band and different ranges, usually near the GPS frequencies. To forestall interference, worldwide agreements and regulatory our bodies , just like the Worldwide Telecommunication Union (ITU), coordinate these frequency allocations. By means of a system of shared requirements and monitoring, GNSS constellations function side-by-side with minimal interference, and “multi-constellation” GNSS receivers can choose up indicators throughout a number of constellations to offer extremely dependable, correct positioning.
That’s a variety of bands! So if each has a selected function and consumer group, why can we make merchandise that tout multiband reception? The brief reply is it offers you higher accuracy. The lengthy reply? Let’s get into it.
What’s so nice about multiband?
The radio spectrum is broad, starting from 3 Hz to 3000 GHz. This implies radio waves can have a wavelength as small as 1mm all the way in which as much as 100km. The frequencies used for satellite tv for pc communications had been chosen resulting from their capability to penetrate by objects and interference, however even inside that small vary, completely different frequencies have completely different traits that make them helpful for various purposes.
Decrease frequencies penetrate by extra materials, however at the price of having decrease bandwidth (much less information per second). Larger frequency indicators with larger vitality are absorbed/mirrored extra simply, however they will carry extra information extra rapidly. Radio is ideal for satellite tv for pc communications due to atmospheric home windows.
Decrease frequency radio waves penetrate the Earth’s ambiance extra simply due to their longer wavelengths, which implies they work together much less with the molecules within the air, permitting them to cross by with minimal disruption, not like larger frequency waves that are extra readily absorbed or scattered by the ambiance’s parts.
When a receiver can absorb information from all these completely different bands, it raises the probability of that receiver getting a sign, which implies a quicker repair and a extra correct repair. Extra info paints a clearer image of precision.
Dilution of Precision
Dilution of Precision is a dimensionless quantity that specifies the error in a GNSS positional repair. This quantity is determined by a receiver’s relative geometry to the satellites it is receiving indicators from. The upper this quantity, the weaker the geometry and the decrease the accuracy of the indicators.
Complicated geometry is used to calculate this quantity, however we have illustrated it for you within the determine set above. In the event you’re counting on a number of satellites, their distribution within the sky is vital – in the event that they’re too shut to one another, your sign turns into much less dependable due to the overlap between indicators.
The extra satellites and indicators you get, the higher your sign will probably be. Because of this getting access to a number of bands and a number of constellations is useful to your accuracy.
What sort of {hardware} is able to multiband reception?
All receivers obtain a base GNSS sign from not less than one constellation; L1 (GPS), E1 (Galileo), B1 (Beidou), and many others. Many receivers can purchase base indicators from all constellations.
Extra superior receivers can obtain a number of bands from all constellations.
SparkFun RTK Side
GPS-19984
SparkFun RTK Side L-Band
GPS-20000
Essentially the most superior receivers can obtain throughout many bands (L1/L2/L5) and constellations.
The following time you are in search of {hardware} in your GNSS tasks, take into consideration what sort of accuracy you are in search of, in addition to reliability in several environments. Multiband is likely to be in your future!
