From advanced research platforms to Unmanned Aerial Vehicles (UAVs), Micro Turbojet Engines (MTEs) have grown to be essential parts in many different kinds of applications. Extensive testing, encompassing analysis, alternative fuel suitability, performance characterization, and control system validation, supports their development. This survey examines the current state of MTE experimentation, along with information on experimental methods, sensor technologies, and new directions in corresponding research. Measurement techniques, alternative fuel effects, characterization of gaseous and particle emissions, and the utilization of experimental data to validate control systems and sophisticated engine models are among the recent advances in test bed design discussed here. Presenting an overall view, the aim is to highlight current challenges and inspire more MTE technology advancement.

Micro-turbojet experiments frequently provide local, software-referenced measurements that must be reconciled before they can be used as thermodynamic cycle states. This study develops and experimentally demonstrates a measured-pressure-constrained inverse thermal-cycle reconstruction for a stationary Swiwin SW190B micro-turbojet. Total/static pressure pairs were measured at the intake and the compressor exit as well as immediately downstream of the final nozzle outlet, while local temperatures, thrust, fuel flow, and rotor speed were recorded independently. Three quasi-steady states at $38.01\times {10}^3$, $67.29\times {10}^3$, and $93.22\times {10}^3{\min }^{-1}$ were retained. Software-zeroed pressure increments were restored to absolute pressure using a common ambient reference, and the measured compressor total-pressure ratio increased from 1.0718 to 1.5298. A two-anchor observation model linked the pressure-constrained compressor total temperature to the local compressor thermocouple and achieved a threefold leave-one-state-out RMSE of 4.10 °C and MAE of 3.75 °C. The reduced model was full rank, with condition number 1.63 and parameter correlation $-0.309$. Conditional Monte Carlo reconstruction yielded cycle-admissibility probabilities of 0.885 and 0.985 at intermediate and high power. Thrust and fuel flow were withheld from the primary inversion and used as independent cross-sensor checks. A one-parameter soft-constraint diagnostic, in which only the existing aggregate compressor-exit-to-turbine-inlet pressure-loss term was adjusted globally across the two non-idle states, quantified the influence of those auxiliary outputs without over-parameterizing the available data; the pressure-constrained solution was retained as the primary reconstruction. The novel aspect of this study is the explicit separation of measured signals, installation-dependent observations, latent cycle states, common-mode pressure uncertainty, and auxiliary-output information within one uncertainty-aware inverse framework. The method provides a transferable basis for thermodynamic reconstruction, measurement consistency assessment, and sensor-information prioritization in compact gas-turbine experiments.