The Data Collection Platforms are used to collect environmental data from sensors and to transmit those data within DCP messages to a DCP Control Centre. The field of DCP application covers beside others:
One objective of the study is the development of a DCP Transmitter covering the GOES 300/1200 Baud, the international 100 Baud LRDCP as well as EUMETSAT’s 1200 Baud HRDCP specification. The certification of the DCP-Tx for HRDCP used via METEOSAT is anticipated.
The second objective is the definition and prototype implementation of a new generation DCP radio interface. One of the cornerstones for the definition of the interface is a survey within the group of DCP stakeholders. This technical questionnaire helps to get external inputs to:
The results of the questionnaire allow to precise the study work on the NG interface. One example specification of the NG air interface is prototyped for the DCP transmitter and the receiver side.
The DCP transmitter shall autonomously work under harsh environmental conditions. Due to this and due to the DCP standards a number of design drivers have been identified such as
Furthermore SCISYS aimed for a common DCP-Tx HW platform supporting the legacy DCP and the new generation air interface. This approach could not be confirmed unless the baseline specification of the new generation air interface was decided.
The DCP market is dominated by US companies. There is no European supplier of DCP transmitters. The DCP-Tx design can serve as a basis for European companies interested in the DCP market.
Beside this the new generation radio interface specification could support the definition of a new international DCP standard closing the bridge between the different DCP specifications used by the different satellite operators.
The DCP-Tx system features are intended to be similar to other DCP transmitters. However the main difference is the support of the METEOSAT HRDCP specification. In addition the same HW shall serve the new generation air interface standard up to a prototype level.
The system architecture as depicted in the following figure is mainly centred on a low power microcontroller, a digital signal processor (DSP) and a dedicated quadrature digital up-converter (QDUC) chip.
The software based transmitter tasks are split to two different processors. The microcontroller is in charge of providing the required serial interfaces for data exchange, monitoring & control, GPS receiver and real time clock (RTC). It performs the time and frequency corrections based on the relevant GPS information on a regular basis.
The actual signal processing tasks like formatting and encoding of the data, symbol mapping and pulse shaping are running on a DSP. This concept provides the highest degree of flexibility due to the fully “software defined radio” approach up to the I/Q symbols at a moderately low sample rate used up to this point. The remaining signal processing is performed within a dedicated quadrature digital up-converter.
Further building blocks are a surface acoustic wave (SAW) band-pass filter before further amplification to the final RF output level by the following high power amplifier (HPA).
The overall project duration is 18 months according to the contract. The basic milestone planning is as follows:
The “-1” milestones are dedicated to the legacy DCP development whereas the “-2” milestones are focusing the new generation air interface work packages.
The legacy DCP-Tx development has successfully passed PDR-1. Currently the detailed design, HW and FW, is produced. In parallel prototyping activities are performed using DSP and QDUC evaluation boards.
The study of the new generation air interface has started. The main study goals have been selected based upon questionnaire results from DCP stakeholders and a workshop between ESA, EUMETSAT and SCISYS. As a result this study focusses on an Enhanced DCP (EDCP)