The limitations in obtaining sufficient datasets for training deep learning networks is preventing many applications from achieving accurate results, especially when detecting new constructions using time-series satellite imagery, since this requires at least two images of the same scene and it must contain new constructions in it. To tackle this problem, we introduce Chronological Order Reverse Network (CORN)-an architecture for detecting newly built constructions in time-series SAR images that does not require a large quantity of training data. The network uses two U-net adaptations to learn the changes between images from both Time 1-Time 2 and Time 2-Time 1 formats, which allows it to learn double the amount of changes in different perspectives. We trained the network with 2028 pairs of 256 × 256 pixel SAR images from ALOS-PALSAR, totaling 4056 pairs for the network to learn from, since it learns from both Time 1-Time 2 and Time 2-Time 1. As a result, the network can detect new constructions more accurately, especially at the building boundary, compared to the original U-net trained by the same amount of training data. The experiment also shows that the model trained with CORN can be used with images from Sentinel-1. The source code is available at https://github.com/Raveerat-titech/CORN. Remote Sens. 2020, 12, 990 2 of 25 Remote Sens. 2020, 12, 990 3 of 25 the same ground truth data. While normally, the detection of new buildings is supposed to use the data in Time 1-Time 2 format, our proposed architecture takes both Time 1-Time 2 and Time 2-Time 1 formats of data to allow learning based on both of the changing features to make it more viable. With this architecture, the amount of training data of the network appears to be doubled. This allows the network to be trained with a greater variation of data, and can result an increased detection accuracy without having to use more SAR data or create any additional ground truths. Moreover, CORN has the potential to use SAR images from other satellites and other environments because the training back and forth causes the model to be more robust.In summary, the objective of this paper is to cope with the lack of training data when training deep learning networks, which leads to inaccurate results in newly built construction detection. We do so by proposing a network architecture called "CORN", which doubles the training set by reversing the chronological order of the dataset. CORN contains two U-net adaptations; one trains on Time 1-Time 2 images, and the other one trains on Time 2-Time 1 images. The proposed network not only increases the detection accuracy, but can also be used in a greater variety of settings of the data; specifically, images from other satellites and other acquisition conditions, including the terrain of the testing area.